- THE DUCT-FREE ZONE JULY 2019
- THE DUCT-FREE ZONE JUNE 2019
- THE DUCT-FREE ZONE – May 2019
- THE DUCT-FREE ZONE – March 2019
- THE DUCT-FREE ZONE – February 2019
- THE DUCT-FREE ZONE – January 2019
- THE DUCT-FREE ZONE – December 2018
- THE DUCT-FREE ZONE – November 2018
- THE DUCT-FREE ZONE – October, 2018
- THE DUCT-FREE ZONE – September, 2018
Category - News
Did you know that New Orleans is built on a swamp?
I was asked that question at a recent mini split class I conducted at my new friend’s, Tommy Flick, Flick Distributing Company, training facility in Harahan, LA. I think that ever since hurricane Katrina, most the planet knows of New Orleans’ unique structure and its relationship with surrounding bodies of water.
I have to admit the class found me ill prepared for several questions I got that evening about mini splits and humidity removal. Several attendees in that class seemed to have a predetermined perception that inverter driven mini splits do not do a good job of humidity removal…and humidity removal is a critical issue in New Orleans and surrounding areas.
In all my travels over the past three years and all my mini split classes over the last ten years, I had never had this issue come up…at least not in as persistent and consistent a manner as it did in my New Orleans class.
Well, you know me…this became a mission! I don’t like not having the answers and I’m never going to ‘wing it’ so finding the answer to inverter mini splits and humidity removal was my number one priority once I returned to New York.
The following represents my findings…
The first point regarding dehumidification when it comes up in a mini split conversation, (or ANY conversation for that matter), is that unless you have a Koi pond, water slide or hydroponic crop in your home, the source of the humidity is NOT found within the home…humidity issues are almost always the symptom of much larger problems such as a high level of infiltration. An entire industry has sprung up in the US dedicated to such issues…The Building Performance Institute BPI, has a ‘certification’ for such issues and a ‘blower door test’ will determine the source of infiltration.
No matter what type of AC system a structure might have, excessive infiltration must be addressed at its source…and that ain’t got nuttin’ to do with the AC system!
That all said….
I have almost 30 years of experience with Small Duct High Velocity SDHV air conditioning systems…I conducted SpacePak’s training in the NJ / NY market for 20 years. I mention in my inverter mini split class that SDHV is similar to inverter mini splits in that the delta T SDHV sees across their evaporator coil, (25 – 35 degrees), is extreme as compared to conventional ducted systems where a 10 – 15 degree delta T across a standard A-coil would be within specification. SDHV removes 40% more humidity than a standard ducted system and the extreme delta T is one reason why! If you look at the refrigerant coil of a SpacePak air handler, it is six rows deep…the air has more opportunity to have contact with the coil and thus the delta T increases and a secondary result of this is increased humidity removal.
Comfort-Aire & Century mini splits enjoy this same benefit…the delta T of 25 – 32 degrees on their evaporator has the same benefit as SDHV and as a result you see the following published performance:
B-VFH09MA-1 dehumidification = 1.69 pints / hour (wall mount)
B-VFH12MA-1 dehumidification = 2.96 pints / hour
B-VFH18MA-1 dehumidification = 3.80 pints / hour
B-VFH12CA-1 dehumidification = 2.96 pints / hour (ceiling cassette)
B-VFH18CA-1 dehumidification = 3.80 pints / hour
B-VFH24CA-1 dehumidification = 5.28 pints / hour
When placed in the DRY mode the above performance will increase dramatically…I will get into specifics in just a moment but first…
Take a look at this….
Heat Controller / Comfort-Aire / Century is also in the dehumidifier business. Their model
BHD-701 -H has the capacity to remove 70 pints / day or 2.92 pints / hour. This unit pulls 6.9 amps and has an operating sound level of 58.5 dBA. This is the largest standalone dehumidifier they make. The unit is designed specifically for ‘extremely wet’ conditions. It should also be noted that this is an Energy Star rated unit with an energy factor of 1.85 liters/kWH
The B-VFH12MA-1, (12,000 BTU), wall mounted evaporator will remove 71.04 pints / day or 2.96 pints / hour, pull 7.6 amps, (when connected to a A-VFH18DA-1 outdoor unit), and have an operating noise level as little as 21 dBA…and additionally provide the primary benefit of COOLING!
…oh yeah, and it will heat like crazy as well!
The humidity removal performance of the two above is almost identical so I’m comfortable in saying that the B-VFH12MA-1 has equal humidity removal performance to that of an Energy Star rated, 70 pint / day dehumidifier with a 1.85 EF, (Energy Star status requires less than 1.90 EF for a dehumidifier capacity less than 75 pints / day).
OK…time to talk turkey!
I wanted to see for myself just how effective an inverter mini split is at humidity removal so I conducted a test in my lab here in New York. The test and its results have been posted on my website in the form of a video titled, ‘COMFORT-AIRE B-VFH09MA-1 HUMIDITY REMOVAL TEST’. The video can be viewed by going to my website, www.ESPCOtraining,com and clicking on MEDIA in the upper tool bar and then clicking on VIDEOS…it will be the first video listed.
My lab is a 10’ X 20’ prefabricated garage…no insulation and no sheet rock. ..a ‘sieve’ you might say! This actually works in this case as it goes to my earlier statement regarding the source of humidity.
Here are the parameters of the test:
DURATION: one hour
STARTING HUMIDITY LEVEL: 79.8%
STARTING DEW POINT: 78.4F
STARTING WET BULB: 80F
EQUIPMENT: Comfort-Aire model B-VFH09MA-1, 9000 BTU wall mounted indoor unit with
A-VFH24TA-1, 24,000 BTU outdoor unit
I started the test with the system in the COOL mode with a setpoint temperature of 68F. The indoor unit’s fan was producing 327 CFM with a supply, (discharge), air temperature of 59F.
I then put the system into the DRY mode with the same setpoint temperature of 68F. This reduced the fan speed by 43% bringing it to 182 CFM.
25 minutes into the test, the following were the recorded conditions:
HUMIDITY LEVEL: 63.2%
DEW POINT: 59F
WET BULB: 63.6F
The supply air temperature dropped to 55F when placed in the DRY mode.
33 minutes into the test, the following were the conditions recorded:
HUMIDITY LEVEL: 58.5%
DEW POINT: 59.9F
WET BULB: 65.3F
The conditions recorded at the end of the one hour test are as follows:
HUMIDITY LEVEL: 52.8%
DEW POINT: 58.4F
WET BULB: 64.9F
I collected the condensate that the indoor unit produced during the one hour test and it measured 5.75 pints.
The proof is in the pudding…or in the condensate in this case!
The end result of our test was a 43% reduction in humidity and 15F degree reduction in wet bulb all from a 9000 BTU inverter wall mounted indoor unit producing 5.75 pints of condensate.
A couple observations beyond the obvious:
The lion’s share of the humidity reduction took place within the first 25 minutes of the test which is good news for homeowners who work all day and leave their systems off…relief comes very quickly!
The DRY mode is the key here…it increased the published humidity removal, (pints / hour), by 70%!
CONCLUSION: Inverter mini splits remove a boat load of humidity…a ton of humidity…all puns intended!
NOTE: A special THANK YOU to Tommy Flick for what was a standing room only training event in his beautiful facility… Tommy actually BBQ-ed a pig himself the day before the class so we all enjoyed pulled pork for dinner…it tasted so good that it was well worth the risk of possible spontaneous combustion when 30+ men consume pulled pork in close quarters!
Thanks to all who attended for inspiring me to research their question and conduct the aforementioned test.
HAVE A GREAT SUMMER EVERYONE!
See you soon!
The views and opinions expressed in this newsletter are those of the author and do not necessarily represent those of ESPCO’s sponsors and training partners.
What is the definition of ‘critical charge’?
The American Society of Heating, Refrigeration and Air Conditioning Engineers (ASHRAE), defines ‘critical charge’ as follows:
“Refrigerant quantity required by a system to maximize performance when a capillary or fixed restriction expansion device is used.”
The inverter mini split world has been using the term ‘critical charge’ in describing the critical nature of the charge in their systems but if we look at the literal definition of ‘critical charge’ it is an inaccurate use of the term…I have been guilty of this myself.
Most inverter mini splits utilize an Electronic Expansion Valve (EEV) as the refrigerant metering device. The EEV by its anatomy is NOT a ‘fixed restriction expansion device’ like a traditional capillary tube or Thermostatic Expansion Valve (TXV).
The following comes from an article written by John Tomczyk, a professor of HVACR at Ferris State University and published in the August 2, 2004 issue of The ACHR News:
“EEVs control the flow of refrigerant entering a direct expansion evaporator. They do this in response to signals sent to them by an electronic controller. A small motor is used to open and close the valve port. The motor is called a step or stepper motor. Step motors do not rotate continuously. They are controlled by an electronic controller and rotate a fraction of a revolution for each signal sent to them by the electronic controller. The step motor is driven by a gear train, which positions a pin in a port in which refrigerant flows.
Step motors can run at 200 steps per second and can return to their exact position very quickly. The controller remembers the number of step signals sent by the controller. This makes it possible for the controller to return the valve to any previous position at any time. This gives the valve very accurate control of refrigerant that flows through it. Most of these EEVs have 1,596 steps of control and each step is 0.0000783 inches”.
So, by the strict interpretation of the ASHRAE definition of ‘critical charge’ and the nature of the anatomy and function of an EEV, the term ‘critical charge’ does not apply to most inverter mini splits…so what do we call it?
Well, here is my proposal…‘Non-Fixed Orifice Critical Charge’ (NFOCC).
Are we splitting hairs here…maybe…but this misuse of the term ‘critical charge’ was brought to my attention in a recent mini split class I conducted in Canada and I had to admit to the faux pas.
Another area where the literal definition of ‘critical charge’ does not apply to most inverter mini splits is the fact that rarely is it required for an installer to remove refrigerant should the installer not use the maximum lineset length determined by the
pre-charge. Where a receiver is present in these systems, any unused refrigerant will be stored in the receiver…in smaller systems that do not have a receiver; unused refrigerant will be stored in the accumulator. If the charge was truly defined as ‘critical charge’, refrigerant would need to be removed in this scenario.
The charge in inverter mini splits is so…here I go again…critical, that it can’t be over stated…these systems are a hot mess, (pun intended), when the charge is less than exact! I have experienced this first hand…you can convince yourself that the problem is in a control board, (either indoor unit or outdoor or both), and in fact your problem is being under charged.
Here is my advice when you have a problem with an inverter mini split system…pull the charge, calculate the weight of the correct charge and weigh it in…trust me…more often than not this will lead you toward resolution of your problem!
14/4 wire – 14/3 with ground wire? Tomato – tomahto?
I had another interesting discussion come up in Canada about the wire / cable requirement between the Comfort-Aire inverter mini split outdoor and indoor units. I have been describing the cable as 14/4…14 gauge wire, 4 conductors. A gentleman attending a mini split class stated it is 14/3 with ground…
tomato – tomahto?
I never had this come up before…I always thought it was pretty straight forward but I do see in the MARS product catalog, (they got EVERYTHING), that it is stated and available as both…14/3 with ground and 14/4.
Hey look, I’m no electrician, but best I can tell the only difference between the two is that in 14/3 with ground, the ground wire is bare and solid and in 14/4 the ground is insulated, (green).
Seems to me both will work just fine for the Comfort-Aire VFH, VMH and DV equipment.
Class notes downloads
The past couple years I have been making the class notes for all my classes available as a download on my website. The past six months has seen the curriculum for all my classes change substantially and as a result I encourage all past students to once again download the notes for the class you attended…there’s a lot of new stuff in there!
If you have forgotten your password, just email me with the subject of the class you attended and where and when the class was held I will email you back with the password.
I suggest downloading the class notes at least once a year as the products change, technology changes and my class curriculums change accordingly. You can update yourself by simply downloading the class notes…no need to take the course again…unless you want to! I would be glad to see you again!
I strongly suggest anyone who attended a mini split class in the past to download the notes again…this subject has seen the most changes to the curriculum and I believe you will be pleasantly surprised how multi-zone mini split technology has continued to evolve.
Just click on ‘DOWNLOADS’ in the upper tool bar. Click on the class subject you attended and then enter your password…you can now download the class notes.
Some months back in a previous newsletter I wrote about my positive experiences with the business networking tool known as LinkedIn. I want to re-visit the LinkedIn subject with you once again.
After each class I conduct, I use the class sign-in sheet to capture attendee’s email addresses so I can add them to my newsletter distribution list and I also check to see if the attendee is registered on LinkedIn…if they are, I send them an invitation to ‘connect’.
Let me say again, as I have said many times…LinkedIn is NOT social media! I hate social media…right or wrong, I am NOT on Facebook or Twitter and have no desire to find old girlfriends, (there weren’t many anyway), or kindergarten classmates. I find the concept of social media to be a bit creepy…there is usually good reason why we move on from people in our past.
LinkedIn is business networking…I don’t care if you’re a one man / woman ‘Mom & Pop’, (or just Mom or Pop), in the HVACR contracting world or you’re a big HVACR manufacturer…you will find it beneficial to use LinkedIn. LinkedIn can help you find new clients, stay in touch with current clients and expose you to ideas, companies, products and people that you otherwise may not have encountered on your own.
You may find a new job…you may find your next employee through LinkedIn.
Look, we all need a little help growing our business and staying ahead of the curve…LinkedIn is a tool to help you do just that.
You can register for LinkedIn here.
Give it a try and when you do, send me an invitation to ‘connect’…I will look forward to it!
I haven’t written anything other than serious HVAC stuff in a long time so a little music discussion is long overdue.
I just came back from a week in Canada conducting mini split classes. I got turned on to a band from Kingston, ON. called ‘The Tragically Hip’.
One of the many reasons I love working in Canada is I always get turned on to music I haven’t heard down here in the States. Canadian radio stations are actually mandated by law to dedicate at least 35% of their air time to Canadian artists…I think this is a great concept!
As you would expect, you hear a lot of RUSH, The Guess Who, BTO and Gordon Lightfoot, but you also hear bands like Doug & The Slugs, Big Sugar, The Kings, Coney Hatch and The Tragically Hip, (the locals just call them ‘The Hip’).
The Hip have a tune you got to check out titled, ‘50 Mission Cap’. It is the story of the 1951 Toronto Maple Leafs and their Bill Barilko. Bill scored the winning goal clinching the 1951 Stanley Cup for the Leafs…and then four months later he went missing. The Barilko story is fascinating and the song does a masterful job of telling that story in a clever and rocking manner.
Check out The Tragically Hip performing ‘50 Mission Cap’ back in 1993 on YouTube.
A special thanks to my friend Mike Duffy of Delta Components for turning me on to The Hip!
See you soon!
The views and opinions expressed in this newsletter are those of the author and do not necessarily represent those of ESPCO’s sponsors and training partners.
Why is Commercial Water Source Heat Pump (CWSHP) technology the best kept secret in HVACR?
I have been preparing for a two week tour of the Pacific coast which will include a couple ‘Introduction to Commercial Water Source Heat Pump Heating & Cooling’ classes, (see www.ESPCOtraining.com for class dates, times and locations). I have had this class in my repertoire for a few years now and I felt it was time to overhaul it and freshen it up a bit.
I was surprised to find in my research of the subject that there is very little information about CWSHP available…I mean like close to nothing! Compared to the abundance of information available about geothermal, (the sexy version of water source), it really seems like CWSHP is a secret that needs to be told…and since I have never been any good at keeping secrets, I’m here to spill the beans!
Before I get into the nuts and bolts of CWSHP, let’s take a minute to look at what is the latest craze in HVACR right now…Variable Refrigerant Flow (VRF) ductless split systems. VRF is getting a lot of attention for many reasons, not the least of which is the fact the these systems can heat and cool at the same time…a wonderful advantage for commercial buildings where core, (interior), offices may require cooling when perimeter offices may require heating…all at the same time! VRF is fascinating technology but it’s not all fairy dust and rainbows…the technology is very complicated making the proper installation tricky and the equipment ain’t cheap!
There is an alternative to VRF that fulfills many of the same goals, (most notably simultaneous heating and cooling), at a fraction of the cost with proven technology that most guys my age, (old that is), feel comfortable with and has been around in its simplest form since time immemorial…you guessed it…Commercial Water Source Heat Pumps!
So how do these mysterious little anomalies work? Well, let me tell ya…
A Water Source Heat Pump is a self-contained water cooled packaged heating and cooling unit with a reversible refrigerant cycle. During the cooling mode, the tube-in-tube (coaxial) heat exchanger functions as a condenser and the coil as an evaporator. In the heating mode, the tube-in-tube heat exchanger functions as an evaporator and the coil as a condenser. A reversing valve is present in the refrigerant circuit permitting changeover from heating to cooling and vice versa.
Multiple WSHPs utilize a single hydronic (water) loop with a boiler or water heater as well as a cooling tower in the loop. The loop is often referred to as the ‘condenser loop’. The heat rejected by the units in the cooling mode is absorbed by the condenser loop and used to warm the units, (zones), calling for heat. A boiler or water heater is generally used for adding heat, (BTU’s), to the condensing water during peak heating periods.
The system also utilizes a water cooling tower to reject the heat energy from the condenser water loop during periods of high cooling demand.
In cold weather, the condenser loop supply temperature can be about 70°F with return temperatures around 64°F…the boiler / water heater is on, the condenser loop pump is on and the cooling tower is off.
In hot weather, the condenser loop supply temperature can be about 85°F with return temperatures around 95°F…the cooling tower is on, the condenser loop pump is on and the boiler / water heater is off.
In certain times of the year, (generally spring and fall), the system actually becomes ‘balanced’ where the condenser loop components, (boiler / water heater and cooling tower), are dormant, (off), and the WSHP units themselves do all the work. The units in the interior of the building where cooling is required reject their heat to the condenser loop water, (via the coaxial coil), which is absorbed by the perimeter units where heating is required. The only component of the condenser loop energized through this period is the loop pump which keeps the water flowing throughout all the WHSP units so units that are cooling and units that are heating can all work in concert with each other utilizing each other’s rejected BTU’s.
How cool is that? (pun intended)
These systems are universal in their applications throughout North America. I have conducted my class in Florida, New England, Canada and now the left coast. No matter what the climate, CWSHP can solve tough heating and cooling problems for commercial buildings of all sizes with relatively simple technology applied in a unique manner…what I like to call ‘good ole American ingenuity’!
Advantages of these systems beyond what I have already discussed are; the ability to ‘zone’ and the ability for those zones to adapt to changes in location, size and occupancy…i.e., one tenant moves out, another moves in who requires a different floor / wall plan within the space, the CWSHP system can be easily adapted to the new occupants needs.
A distinct advantage that these units have over ‘central ducted’ type systems is that since they do not share a common ducted system, any airborne contaminants which may be present in one zone is not transported via common duct to another zone, i.e., if the accounting department has the flue, the sales department won’t be effected.
Normally, multiple units serve an occupied space so there is built in redundancy so should one unit go down, there is another in the same space / zone providing some conditioned air until the down unit can be repaired or replaced.
…and speaking about replacement…
The ‘packaged unit’ concept of the CWSHP allows for quick change outs when required. This is great business guys…replacements units are available from my good friends at Comfort-Aire® that replace a wide variety of other manufacturer’s units and are available for quick delivery!
If you are at the AHR EXPO in NYC next week, drop by the Heat Controller / Comfort-Aire® booth #1607 and talk to the CWSHP pros from Comfort-Aire®!
Keep an eye on my website for a CWSHP class coming to a town near you in 2014. I will tell you this straight up about the class…it is not for the faint of heart! I go through the equipment selection process for new jobs as well as troubleshooting of both the water and refrigerant side of the system. You will learn how to calculate both the Heat of Rejection HR, (cooling), and Heat of Extraction HE, (heating). Your sixth grade math teacher, old lady Gillacuddy, will be proud as you put our math skills to work!
AHR EXPO 2014
I will be roaming around the EXPO aisles so if you see me please stop and say hi…I’m the old, fat, hippy looking guy…actually, here in NY that describes a lot of us!
HVACR Workforce Development Foundation
The HVACR Workforce Development Foundation is dedicated to leading an industry effort to develop and promote educational projects, programs and partnerships to attract committed and skilled employees to a career in HVACR.
- To raise the awareness of the HVACR industry and the importance it plays in daily lives.
- Create interest in the HVACR industry as an attractive and profitable career choice.
- To enhance the quality and quantity of available workforce for the HVACR industry.
As an HVACR industry ‘trainer’, I applaud the efforts of the foundation and I support their goals, as their goals are the same as mine…to raise the general perception of our industry and attract young, talented men and women to our workforce.
I have posted a video about the foundation at my website, Click here…the video about the foundation is the first one you will come to.
I encourage you to use the foundation’s website as a resource. You can visit them at http://www.careersinhvacr.org
The site is a clearinghouse for information about HVACR training programs throughout North America, scholarship programs and job postings. The foundation is the HVACR industry at its best…we recognize how good the industry has been to us and our families and we want to share that with the next generation…not only to insure their success, but to ensure the success of this wonderful industry for generations to come.
New videos posted on the website:
Besides the video I mentioned above, there are a couple more new videos posted since the last newsletter. ..be sure to check’em out!
Geothermal in Canada…’the times they are a changin’:
I received this very interesting article from my good friend, Hans Gautschi of HRC Services, about regulations imposed on geothermal drilling in Ontario…and new Canadian national standards which may have an effect on the industry as well. You can read the article here.
Do flat plate thermal solar collectors hold snow?
I haven’t done a thermal solar class in a while but when I was a player in that market a few years back, I remember an ongoing debate about flat plate versus evacuated tube collectors was ‘which will hold snow and which will not hold snow’?
Many of you know that I have a Sunnovations® Thermal Solar System (TSS) installed at my home that produces most of the domestic hot water for our home year round. I took some pictures of the collectors after a recent snow storm and I have posted them on my website…you can see them here. You will see definitive evidence that flat plate collectors do indeed hold snow.
The flat plate ‘community’ would insist that their preferred collector would not hold snow and that the evacuated tube collector would. My position at the time was that since the tube collector was just that…a series of tubes with space in between each tube, the tubes stood less chance of holding snow because the snow would simply fall through the spacing of the tubes whereas the flat plate had no defense against snow. I think the pictures prove my point.
I believe the myth about flat plate collectors and snow came from the fact that a flat plate collector will indeed be hot to the touch when in direct sun light but an evacuated tube’s surface will be at ambient temperature. This is all true but the problem with this argument as it relates to snow is that the sun is not shining during a snow storm and thus the surface of the flat plate collector will too be close to ambient temperature and as a result…hold snow.
Bottom line is snow is a temporary hindrance to flat plate solar collectors…the good news…in a day or two of sunshine all is right again!
See you soon!
The views and opinions expressed in this newsletter are those of the author and do not necessarily represent those of ESPCO’s sponsors and training partners.
There are a total of 29 videos now posted on the website. I debuted a ‘video series’ at the Heat Controller national sales meeting in Las Vegas this past October. The subject of the series is a singular project… a 22’ X 12’ ‘four season room’ or what some call a ‘Florida room’.
I chose this project for several reasons; first, it is an application where a mini split is going to be used as a primary source of heat. This particular room has screened panels installed for the spring and summer and glass panels in the fall and winter. The mini split will never be used to cool the room as a result of it being open via the screened panels but it will be heated by the mini split once the glass panels are installed so the room can be utilized throughout the fall and winter. My friends up in Canada have been using mini splits for heating applications for some time now and I wanted to share the ‘genius’ of their adaptation of this product to the rest of North America…and beyond!
Secondly, this project thinks ‘outside the box’… both figuratively and literally. It stretches what has previously been seen as the limitations of mini splits and takes it to some new application frontiers.
Third, being that it was a single room application it was a relatively simple job to document in video form and present the entire project from the design / sizing stage to actual system performance under load.
The first installment is titled, ‘Sales Training Video #1: System Sizing’. Let me get this out of the way now…please don’t be turned off by the words, ‘sales training’, in the title. This series of videos was created by me to assist you on many levels…including how to sell a mini split job. Let’s face facts…you can’t demonstrate your mechanical skills if you can’t ‘sell’ the job so the videos touch on not only the design and installation but how to approach the job with the homeowner.
In video #1 I use the sizing software I told you about in last month’s newsletter, the HVAC-Calc software by Don Sleeth of HVAC Computer Systems, LTD.
You get an opportunity to see how easy this software is to use and ultimately how effective it is in creating ACCA Manual J based load calculations.
Video #2 is titled, ‘Sales Training Video #2: How to Sell & Install a Mini Split for a Four Season Room’. This video takes you through the entire installation of the system from A to Z. Although this video is quite comprehensive, you may still wish to view other videos on the website which detail system pressure testing with nitrogen, system evacuation and system charging.
Video #3 is titled, ‘Sales Training Video #3: Jobsite Electrical Evaluation’. This video is dedicated to just the electrical side of the job…from evaluating the existing service within the home as well as how to utilize installation accessories such as a Surge Protection Device SPD like the MARS 83900 which I introduced to you in last month’s newsletter.
Lastly, in video #4 titled, ‘Sales Training Video #4: System Performance’, the system is now up and running and the outdoor temperature is dropping… you can see the results as the system takes the room from 40 degrees to 72 degrees in less than 1 ½ hour at 40 degree outdoor air temperature.
I actually plan to expand on the last video as the temperature here in Orange County, NY, (where the job is located), continues to drop this winter.
Video #4 also shows a potential problem with the system that was detected once the system was commissioned and how the ‘follow me’ mode of the wireless remote was employed to resolve that problem… check it out!
As always, remember all the videos on the website are intended as a technical resource for you but local codes and regulations ALWAYS take precedence.
‘What Delta T should I be seeing across the heat exchanger on my geothermal heat pump’?
I had this question come up at a geothermal class I conducted in Boston this past October 29.
The answer is, ‘well, it depends’…
Let’s use the Comfort-Aire model HTV048, vertical upflow, 3 ton water to air geothermal heat pump as our example. We need to reference the unit’s typical operating temperatures and pressures in the product’s IOM and you can find it for the HTV048 here (PDF).
Scroll to page 35… you will find the chart for the HTV-48 at the bottom of page 35.
Once you find the chart for your specific product / model, then you need to determine what the entering water temperature to the heat pump is…this will ultimately determine where you enter the chart.
Let’s use an example of 50 degree entering water temperature. You will find this in the first vertical column from the left, second horizontal column down.
Now, let’s move just one vertical column to the right and find the GPM / ton for which our system is designed… I promote the closed loop industry standard of 3 GPM / ton, (which in this case would actually be a system requirement of 12 GPM based on our 4 ton heat pump).
Now that we have the horizontal axis from which we work, let’s move to the right hand side of the chart to the heating mode specifications.
The second to last vertical column is the ‘water temperature drop F’…and in our case we should see a delta T of 5.7 – 7.7 degrees Fahrenheit. So there you have it… for our example, we would be looking for a temperature drop, (delta T), across the water side of the Ground Source Heat Pump’s GSHP heat exchanger of 5.7 – 7.7 degrees.
Don’t sound like much does it? One always has to remember that a GSHP uses the refrigerant side of the system to heat or cool the air being used to heat or cool the home so the water side is simply used for the extraction, (heat mode), or rejection, (cool mode), of heat to and from the house to the ground. It is because of the refrigeration side that we can heat a home with a ground temperature of 50 degrees or even less, (think about all those wonderful geothermal system in Canada…they can only dream of a ground temperature of 50 degrees).
We can see some other interesting phenomenon which takes place from the operating temperature and pressures chart; let’s go back to the second vertical column,
‘water flow GPM / ton’.
Note that as you slow down the flow through the ground heat exchanger you increase the
delta T across the GSHP heat exchanger, i.e., drop the flow to ½ of our previous example, (1.5 GPM / ton), and now your delta T almost doubles, (11.3 – 13 .3 F).
What if your delta T across the GSHP’s heat exchanger is not within the product’s spec? Well, it could be an indication of a problem, i.e., low delta T could indicate an under charged system, high delta T could indicate an over charged system.
I suggest going back and reviewing my April, 2012 and May, 2012 newsletters, (you can see them by scrolling down through archived newsletters under the ‘What’s New’ tab on the website), for more details about geothermal system performance and diagnostics.
So the answer to the question, ‘what delta T should I be seeing across the heat exchanger on my geothermal heat pump’ can’t simply be answered with a ‘rule of thumb’… you have to look at the system in its entirety and go to the product performance specifications.
Spring 2014 training schedule coming soon!
Please keep an eye on the website for spring 2014 training dates soon to be posted. Here is a sneak preview:
WEEK OF 2/3/14
WEEK OF 2/10/14:
West coast to include, California, Oregon, Washington & Nevada
WEEK OF 2/24/14:
WEEK OF 3/3/14:
WEEK OF 3/10/14:
South Dakota, Minnesota & Wisconsin
WEEK OF 3/24/14:
WEEK OF 3/31/14:
WEEK OF 4/7/14:
WEEK OF 4/21/14:
WEEK OF 4/28/14:
What mini split outdoor unit mounting brackets are you currently using?
I need your help! I’m hoping you all could answer the subject question along with the following:
- What mini split outdoor unit mounting brackets are you currently using?
- Why do you use this particular bracket?
- What is the percentage of jobs that require mounting brackets?
- Is the material the bracket is made from important and if so, why?
- What is the average cost of these brackets?
If you would take a moment to answer each of these questions via return email it would be of great help to me.
I am testing an AC/R leak sealant product in a single zone mini split inverter system with a capillary tube metering device…I hope to report on it’s performance in the next newsletter.
I will be creating installation and performance videos for a new Comfort-Aire product… electric infra-red heaters. These are NOT the heaters you see at the Sam’s Club and in SkyMall magazine… these are super high quality and I look forward to sharing this product with you in the next newsletter.
As a 30 year season ticket holder of the New York Jets in the NFL, I have been forced to seek competitive football anywhere I can find it. Many of you know that I am a huge Calgary Stampeders fan… you will see in video #1 of the four video series that I referenced earlier, I predict the Stampeders will win the 2013 Grey Cup…they did not. The Stamps didn’t make it past the semi-finals where they lost to the Saskatchewan Roughriders who ultimately won the cup.
You can see pictures of me in my Stampeder garb in the ‘Gallery’.
Just like I have been saying about the Jets for the past 30 years…’we’ll get’em next year’!
2013 coming to an end…
I just want to thank all the distributors who hosted training classes this year, the local reps who promoted them and especially those installers and service technicians who give me the privilege of spending 3 – 4 hours with them…to you I dedicate all my efforts as you are the wheels that keep this wonderful industry of ours moving forward. THANK YOU!
HAPPY HOLIDAYS AND A HAPPY NEW YEAR TO ALL!
See you soon!
The BEST heat gain / loss calculation software I have ever used!
One of the reasons I write this newsletter is to inform you when I discover something really cool and / or something that makes my life in the HVACR biz easier…and here is something that hits both marks!
I have been searching for an easy to use, ACCA Manual J based software program for heat gain / loss calculations. I have used programs offered by equipment manufacturers and others offered by software writers and frankly, none were for me.
Now that is the key…they were not for ‘me’.
I’m going to share something very personal with you…I’m lazy. Not the ‘can’t get out of bed’ kind of lazy but rather the more benign type. The type of lazy where I just can’t get myself to sit at a desk and do mind numbing, math laden, monotonous heat gain / loss calculations…it has always been something I dreaded.
I’m old enough to have attended IBR schools for heat loss calculations back in the 70’s. The Institute of Boilers and Radiation, IBR, had a wonderful traveling class that pre-dated the hand held calculator. You would attend an IBR school and be taught to perform a heat loss for an assigned structure by using the IBR Heat Loss Calculation Guide #H-21, (which I still have to this day), a ruler, a pencil and a legal pad…that was it!
It reminded me too much of real school and for me that was a turn off and it probably affected my attitude toward these calculations for life.
I decided to take the 21st century approach to research and I simply Googled, ‘best HVAC heat gain / loss calculation software’ and the name that kept coming up in HVAC blog and bulletin board conversations was Don Sleeth of HVAC Computer Systems, LTD.
Don is the creator of HVAC-Calc software. Don has been doing this type of work for some of the biggest names in the biz as far back as 1981. The product he offers today is the result of over 30 years of development.
Some of the many features that I find particularly helpful are:
- Help, right on screen, where and when you need it.
- ‘Think Ahead’ technology anticipates your next move, saves you precious time.
- All construction data is presented on screen, in English, no code numbers, no searching, no scrolling
- ‘Think Ahead’ technology automatically pre-selects the construction type, based on your past preferences.
- Check the load of any individual item immediately.
- View the whole house load as you go, watch it grow as you add components.
- Automatically saves your work as you do it…for those of us who have spent hours on a design only to ‘loose’ it, this is especially helpful!
- Each job is saved with a full name and address, date modified as well as an unlimited comment; no cryptic file names to try and remember
I will be using the HVAC-Calc software in future ‘Introduction to Geothermal Heating & Cooling’ classes starting in October, 2013. The combination of the HVAC-Calc program and Comfort-Aire’s ‘LoopLogix’ software make an invaluable tool for geothermal design.
You can take a trial run at:
Guys, I never thought I would endorse a heat gain / loss software product simply because I didn’t think one existed that truly made the process simple, easy and quick…but I was wrong. I cannot say enough about Don Sleeth and his HVAC-Calc software…download the trial version today and give it a try!
Speaking of upcoming classes: New class dates for the fall and winter 2013 are being added to the website so be sure to keep an eye out for a class coming to a town near you. You can see upcoming training events at this address:
Are you using a surge protection device on your inverter mini split installs?
You should! I was surprised to learn that in many inverter type mini split systems, the ‘main board’ of the outdoor unit, ODU, is surge protected but the inverter and PFC boards are not. Thus, the need for ‘external’ surge protection…like the MARS 83900 Surge Protection Device.
Let’s first discuss exactly what a ‘surge’ is and why equipment needs to be protected from it.
I found a great article by Tom Harris, (staff writer for Discovery’s Howstuffworks), ‘How Surge Protectors Work’…the following is an excerpt:
‘A power surge, or transient voltage, is an increase in voltage significantly above the designated level in a flow of electricity.
To understand the problem, it is helpful to understand something about voltage. Voltage is a measure of a difference in electric potential energy. Electric current travels from point to point because there is a greater electric potential energy on one end of the wire than there is on the other end. This is the same sort of principle that makes water under pressure flow out of a hose — higher pressure on one end of the hose pushes water toward an area of lower pressure. You can think of voltage as a measure of electrical pressure.
Various factors can cause a brief increase in voltage.
- When the increase lasts three nanoseconds (billionths of a second) or more, it’s called a surge.
- When it only lasts for one or two nanoseconds, it’s called a spike.
If the surge or spike is high enough, it can inflict some heavy damage on a machine. The effect is very similar to applying too much water pressure to a hose. If there is too much water pressure, a hose will burst. Approximately the same thing happens when too much electrical pressure runs through a wire — the wire “bursts.” Actually, it heats up like the filament in a light bulb and burns, but it’s the same idea. Even if increased voltage doesn’t immediately break your machine, it may put extra strain on the components, wearing them down over time’.
Come on fellow ‘wet-heads’, you got to love Tom’s analogy of water pressure and electricity…it makes perfect sense now, doesn’t it?
Tom’s article continues:
A more common cause of power surges is the operation of high-power electrical devices, such as air conditioners and refrigerators . These high-powered pieces of equipment require a lot of energy to switch on and turn off components like compressors and motors . This switching creates sudden, brief demands for power, which upset the steady voltage flow in the electrical system. While these surges are nowhere near the intensity of a lightning surge, they can be severe enough to damage components, immediately or gradually, and they occur regularly in most building’s electrical systems’.
How does a Surge Protection Device, SPD, work?
A surge device absorbs surges, spikes and transients through the use of Metal Oxide Varistors, MOV, and dissipates them as heat and shunts them to ground. During this process the MOV can get warm and in some cases, a thermal failure can occur if the spike is significant.
MARS surge devices use a patented TPMOV, (Thermally Protected MOV). The thermal protection eliminates potentially dangerous thermal failures.
The MARS 83900 protects the entire mini split system, (as long as the evaporator is powered by the condenser as with Comfort-Aire). It installs easily to the system disconnect and features a green LED indicator which when illuminated indicates the MARS 83900 SPD is operational.
MARS SPD’s are type 1 and 2 approved which means they can be installed on the line, (at the breaker), or load side, (at the disconnect), for ease of wiring. The MARS unit can be installed on 120V and 240V systems.
The MARS 83900 has a 3 year product warranty as well as $7,500 connected device coverage.
Keep an eye on my website for a future video showing the installation of the MARS 83900 with a Comfort-Aire, VMH36SC-1 inverter mini split.
Bring the USS Pueblo Home
I was seven years old on January 23, 1968 when the USS Pueblo came under attack by North Korean forces in international waters. The crew of the Pueblo staved off the attack for two hours as she was pursued by no less than four North Korean torpedo boats, two sub chasers and two MiG-21 fighters. The Pueblo was an ‘intelligence gathering ship’ and as a result she was armed with only a single .50 caliber machine gun and only one crew member was trained in its operation.
One of the sub chasers opened fire with a 57 mm cannon killing 21 year old Petty Officer Duane Hodges from Creswell, Oregon.
The USS Pueblo was boarded by North Korean forces and the crew would serve 335 days as prisoners, enduring brutal physical abuse and mental torture.
Why am I writing about this in my newsletter? Well, for the following reasons…
If you are younger than me, (and everyone is younger than me), chances are good you aren’t aware of what has become known as the ‘Pueblo Incident’. Although I was seven years old, I do have a vivid memory of the news reports and the images of the crew when they were freed on December 23, 1968.
The images and later interviews with the Captain of the USS Pueblo, Commander Lloyd Mark ‘Pete’ Bucher, affected me…I just had a sense that this man was a true hero…it turns out I was right. Cmdr. Bucher is credited, (by his 81 crewmembers), for leading his crew through the 11 months of captivity…leading by example, displaying courage and giving hope as they endured unimaginable brutality.
This is just one example of the brutality Cmdr. Bucher endured;
Cmdr. Bucher describes how he was about to be executed by his North Korean captives when a gun was placed at his head…he wanted his last words…his last thought…to be that of his wife Rose. He shouted out her name just as he heard the click of the gun’s trigger…the gun was not loaded. You can hear Cmdr. Bucher recount this experience in his own words in an interview at this address:
Cmdr. Bucher died on January 28, 2004 at the age of 76. His death was partly attributed to injuries he sustained while a prisoner in North Korea 36 years earlier. Rose Bucher passed away just weeks ago on September 4, 2013.
The main reason for this article is this…the USS Pueblo remains to this day, a prisoner of North Korea. I find this both disgusting and unacceptable. The USS Pueblo is the second oldest still commissioned ship in the US Navy fleet…second only to the USS Constitution which was commissioned in 1797 and moored in Charlestown, MA today. Think about that…the second oldest actively commissioned US Naval ship sits in captivity today in the waters of North Korea’s Botong River in Pyongyang as an exhibit of the ‘Fatherland Liberation War Museum’. ..are you kidding me? This is an outrage!
Here’s what we all can do…write to our representatives in Washington DC and let them know we haven’t forgotten the USS Pueblo. BRING THE PUEBLO HOME!
Look, I know this is not the most pressing issue in today’s international political scene but 45 years have passed and if something is not done soon, the remaining surviving crew members will go to their graves with their ship…our ship…still in captivity.
Please go to the following address for a comprehensive history of everything related to the USS Pueblo and the brave men who served her and their nation.
May I suggest when at the above website, go to the ‘Ships Store’ and purchase a ‘Return the Pueblo’ bumper sticker and put one on each of your trucks.
See you soon!
A bunch of new videos posted on the website!
I have been taking advantage of my time off the road this summer to create some new videos…many of which were inspired by comments from class attendees over the first half of 2013.
I have posted a total of nine new videos all pertaining to the Comfort-Aire, Century and Kerr mini split products. A list of the video subjects is as follows:
- Moving the Refrigerant Into the Receiver
- Forced Operation Mode
- Discharge Air Temperature & CFM
- Lineset Flare Nut Torque
- Refrigerant Recovery
- Inverter Test
- Data Flow Test
- Mini Split Charging
- Mini Split Evacuation
The videos show the use of some great tools and instruments from the Yellow Jacket, REFCO and Fieldpiece companies as well as the Comfort-Aire, Century & Kerr mini splits.
You can see all the videos here.
Record breaking attendance for ESPCO classes in 2013!
The first half of 2013 has been exciting, adventurous…and exhausting! Check out these stats:
- TOTAL INSTALLERS / TECHNICIANS TRAINED: 621
- TOTAL NUMBER OF CLASSES: 45
- TOTAL NUMBER OF STATES: 14
- TOTAL NUMBER OF PROVINCES: 4
- TOTAL AIR MILES TRAVELED: 48,844
Thanks to all the reps and distributors who sponsored classes and to all those who attended!
Stay tuned for class announcements for the fall / winter 2013 which will soon be posted on the website.
How much do you really know about your liability insurance?
I have wanted to share this with you for some time now but have been hesitant until I felt I was out of any legal peril…that time has come, so here goes.
As I sat at my desk back on March 26th of this year, a fax spat out of the machine from a lawyer’s office in Chicago…that’s never a good thing! The very formal, and very scary, correspondence informed me that a fire had taken place in New Jersey and a boiler was suspected of being the ignition source. Here’s what drained the blood from my brain and took my breath away for a moment…the boiler had my service sticker on it!
Yup, this is what we all have nightmares about in our business and it was happening to me…I was truly shaken.
Let me give you some background.
Late 2012 a fire in a condominium complex, where I have done boiler service for many years, destroyed multiple units. I was aware of the fire because it was reported by local TV news and I of course recognized the building. At the time, I really didn’t think much of it as it was in a portion of the complex where I hadn’t worked for many years and I hadn’t worked at all in the complex for at least a couple years.
I also knew of the event because within days after the fire, several residents of the complex who I had worked for in the past called me asking me to ‘service’ their boiler as they were concerned by the recent fire.
This had been the second fire in my memory at this same complex…almost the same units were involved. I decided that I was not going to service the complex any more…just seemed like I didn’t need the risk, (or the work). You know what we always say in this business…’you never want to be the last schmuck to service a piece of equipment and then have it be suspected of causing a fire’!
Ok, back to March 26th of this year.
The letter from the lawyer told me the condominium unit number where the fire was suspected to have originated. This is was invaluable to me because I have EVERY original hard copy invoice that my company has EVER created from our inception and incorporation back in 1995. I actually have my late mother to thank for this!
My mother, the former Rita McDarby, taught me many lessons and one was to keep good records…throw nothing out! Mom wasn’t a hoarder by any stretch, but she kept every paid invoice, receipt, canceled check, etc., and kept them in this huge chest of drawers. I can remember like it was yesterday, her opening one of the drawers that held hundreds…heck, thousands of envelopes. My mom ran a modest household so years and years of documents could be contained in that one large chest of drawers.
Here I am decades later and instead of a chest of drawers, my wife and I keep each year’s documents in huge Tupperware type tubs up in the attic…there are a bunch of them!
Here’s a real interesting coincidence…my wife and I, just prior to receiving this letter from the Chicago attorney, actually considered throwing out some of the older documents. We went as far as to contact our account and asked how far back we needed to keep business records…’three years’ he said. We have a great accountant and he has served us well for many years but I have to admit we are so grateful we did not take his advice…frankly, it might simply have been my laziness and I just kept putting off throwing the stuff out.
OK, back to the subject at hand…the specific address of the suspected ignition source of the fire.
My wife and I pulled all those old records out of the attic and working backwards from newest to oldest, went through EVERY invoice until we found one for the address in question…it was dated November of 2004.
I had not been in the unit in question since November of 2004! Nine years ago!
What did I do nine years ago in this unit? I changed the speed of a three speed pump because the homeowner was complaining of a velocity noise in the hydronic baseboard…that was it…I moved a switch on the pump from speed three to speed two…and nine years later here I am potentially being named in a multimillion dollar damage claim!
Whereas having this document made me feel better about ultimately having my company removed from any potential litigation, as I have said since October of 1995, the OJ verdict, ‘you can’t count on the legal system to always do the right thing’.
My next step was to contact my insurance agent. This agent and agency has handled all of my wife and my insurance needs for decades, both personal and professional. We know him and he knows us…he has been to our home and knows as much about us than most anyone…and he knows who we are when we call…isn’t that novel in today’s world!
I was thrilled that within a few days my insurance carrier had assembled a ‘team’ of professionals assigned to my case…a lawyer and a forensic fire expert among others. These two gentlemen would be a comfort to me moving forward…let me tell you why.
In early June, I was ‘invited’ to a ‘forensic inspection’ of the boiler in question…both gentlemen accompanied me. What a learning experience this was…unless you have gone through this, I suspect you would never know an entire industry exists dedicated to this type of incident.
This ‘inspection’ took place in a warehouse type building filled with ‘evidence’ not only from the case I was there for but also charred automobiles, washing machines, barbeques…you name it! If I had been there under any other circumstances I would have said, ‘wow, this is cool’!
There were more than twenty people there for the boiler inspection…lawyers, forensic experts of all types, local utility people, local fire marshal and the people running the show…this is what they do…inspections of all types carried out in a very legal, almost courtroom type manner.
I’m not embarrassed to tell you that I was nervous and worried. I knew I had done nothing wrong but once again, you can’t trust the legal system to always make the right call. The fact that I had a lawyer and forensic expert with me, advising me, guiding me and telling me that we ‘were in good shape’ and ‘not to worry’…well, I can’t tell you how good that was.
The time came to actually see this boiler that I had not seen for nine years…and suddenly there it was…not looking at all that bad to tell you the truth…certainly not like it had been in a fire.
…and there It was…right on the boiler jacket…my service label. You know what I’m talking about…a label that says, ‘for service call…yada, yada’.
I have to tell you, even with a lawyer and a forensic expert telling me ‘not to worry’, you can’t help but worry when you see your sticker on a piece of equipment in these circumstances.
Let me just throw this in here. It is my understanding that another service company had ‘serviced’ the boiler in question less than 72 hours before the fire…72 hours! I haven’t been there in nine years and can prove it and they got a guy who was there 72 hours prior and their still messing with me…come on!
Look, I don’t want to see anyone get hurt in this situation but certainly the guy who was there three days earlier has a bit more to explain than I guy who was there nine years earlier!
OK, let me wrap this up.
You get a letter from a lawyer telling you may be named in a lawsuit but you do not get a letter saying you won’t be named in a lawsuit. The best that happens is your team advises you that they believe, based on their experience and knowledge of the case, you are in the clear…not exactly what I was hoping for but from what I’m told this is about as good as it gets in the legal world so I’ll take it.
I share this unpleasant experience with you because I think there are many lessons to be learned from this experience…and here they are;
Document the service you performed in the content of your invoice. Include model numbers, serial numbers…be specific about the work you did. Make sure to date your invoice and keep a copy of it…forever!
- Don’t take your liability insurance casually! Know who your agent is and make sure he / she knows you. Know your coverage…not just the dollar amount…be sure you are covered for the different types of equipment you might work on and different fuel types.
- Take pictures of your work…why not? Virtually every service technician has a cellular phone in his / her pocket…tell them to take a few pictures ‘before and after’ and print those images and attach them to the invoice for your records.
- Ask your insurance carrier how they would handle a situation like what I went through…better to know now than find out later!
- Incorporate….I’m a big believer in this! Look, you have to talk to your accountant and lawyer and have them advise you on your specific situation but incorporating does give your private assets protection should a decision go against you.
- Do good work and always be conscious about ‘what could happen’. We deal with combustion equipment, we deal with volatile fuels, with electricity…the safety of our customers and their homes must always come before comfort issues…if something ain’t safe to run then shut it down until it can be repaired or replaced and document the situation.
I won’t feel completely out of the woods with this thing for some time but I felt it important to share this with you because until you go through it, you have no idea just how quickly your business…your life…can be effected by something like this.
Some sad news: I was shocked and saddened to hear of the passing on June 14th of Canadian Comfort-Aire rep, Paul Dion. I spent most of this past April with Paul, traveling the North Atlantic region of Canada…you spend that much time with someone in planes, cars, restaurants and ultimately training classes, and you get to know, (and appreciate), each other pretty well.
Paul was one of the funniest, quirkiest guys I ever traveled with…you had to be smiling when in his presence.
I know if there is a ‘Tim Hortons’ in heaven, (it’s a Canadian thing), Paul is sitting at the counter, having a bowl of soup with the Tim Horton!
I knew and worked with Paul for just a short time but he impressed me on so many levels…a good man in every way.
Have a great, safe & fun summer everyone!
To drill or to trench?…that is the question
In my ‘Introduction to Geothermal Heating & Cooling’ class I speak to the many options for the ‘Ground Heat Exchanger’, GHEX, and I wanted to take the conversation one step further.
In my class, I use a portion of a tutorial for the Comfort-Aire LoopLogix geothermal design software narrated by the great Bob Sykes, retired Director of Sales at Heat Controller, Inc. Bob uses an example of a three ton system and he demonstrates how the LoopLogix software allows the designer to go back and forth from any number of GHEX applications, and in doing so, shows how each application changes the amount of tubing required for the GHEX…in some cases, dramatically changes the amount!I always point out these dramatic changes to the class attendees and I emphasize that one must balance the additional tubing required for ‘trench’ applications with the cost of vertical borehole drilling to truly see which is the more cost effective…that is the ‘next step’ I want to take here.
We need to obviously set a scenario here…not every job allows us the luxury of choosing between trenching or vertical application but for this example we are going to assume we have the land to do whatever we find to be the best, most cost effective approach.
I just spent a couple weeks in the mid-west, (Iowa & Nebraska), and traveling through that very beautiful, (and very flat), part of our great country inspired me to do this exercise. My new friends in the mid-west often have many application options with geothermal as they have plenty of land, (farms), often with ponds and / or small lakes on them. The choice often comes down to cost of tubing and trenching versus cost of vertical drilling.
Let’s use the example Bob Sykes uses in the LoopLogix tutorial. The result of our ACCA Manual J heat gain / loss calculation requires a three ton heat pump. Now, let’s not only see how much tubing, drilling or trenching will be required for this job buts let’s put some real numbers to the example and see where we are at the end…is trenching more economical over drilling or are they a wash?
Ok, let’s start with a vertical GHEX…LoopLogix tells us that based on the design criteria we have entered, a vertical application will require the following:
- Three vertical boreholes of 200’ depth
- 1200’ of ¾” HDPE tubing
Let’s try and put some real costs to this…I’m going to use costs associated with my neck of the woods here in New York & New Jersey and they might be different from where you are so you can make adjustments where needed.
- Three vertical boreholes of 200’ depth
- $18.00 / foot drilling, pipe insertion & grouting
- Three ¾” U-bend coils of 230’ length
- $167.00 / coil
- Three coils = $501.00
- Total cost for vertical GHEX = $11,301.00
Next, let’s look at the same job but now plug it into a two pipe backhoe application. LoopLogix shows us, among many other things, that our annual ‘operating costs’ changes by a whopping $11.00…obviously insignificant. It also shows us the following is required:
- Three trenches 2’ wide X 5’ deep X 577’ length
- 3461’ of ¾” HDPE
- 1154’ of ¾” HDPE per trench
On the surface, (excuse the pun), this might seem like a ‘no brainer’ based on the amount of tubing required alone…the trench application requires almost three times more pipe!
We need to look closer however, to see if indeed this is as simple as it appears.
Like we did with the vertical application, lets apply some real costs associated with the trench application:
- Three trenches of 2’ wide X 5’ deep X 577’ length
- Two day rental for a Case #580M backhoe = $630.00
- Five coils of ¾” HDPE tubing X 700’
- $194.00 / coil
- $970.00 tubing cost
- 2 men labor / two days = $3,680.00
- Total cost for horizontal GHEX = $5,280.00
Pretty dramatic results!
Let’s now take a look at the same job using a slinky GHEX:
- Three trenches 3’ wide X 5’ deep X 200’ long
- 4826’ of ¾” HDPE tubing
- 1609’ of ¾” HDPE per trench
Our tubing requirement has gone up yet again, (by another 1325’), and we also need a wider trench to accommodate the slinky loop diameters of approximately 36”. Although the trench is wider, it is also considerably shorter so I believe two days for trenching is still a reasonable estimation for this application.
- Three trenches 3’ wide X 5’ depth X 200’ long
- Two day rental for a Case #580M backhoe = $630.00
- 4826’ of ¾” HDPE tubing
- Seven coils of ¾” X 700’
- $194.00 / coil
- $1,358.00 tubing cost
- 2 men labor / two days = $3,680.00
- Total cost for horizontal slinky GHEX = $5,668.00
So there we have it…where we can trench, the numbers show it to be the economical choice by far.
You can download the Comfort-Aire LoopLogix geothermal design software for FREE here.
Next time, I want to look at two other popular applications…’pond slinky’ and ‘directional drilling’ and see where they fall in this scenario.
You can now download the notes from any ESPCO class!
Click on the tab ‘Downloads’ on the menu bar and choose the class you attended:
You will need to enter a password in order to download the notes…passwords will be given at each class and each class has its own unique password. Those students who attended a class in the past and still want to download the notes can email me directly at:
You will need to provide me with the date, location and subject of the class you attended and I will forward you the password.
Kerr Controls of Canada
I have added some pictures of the classes I conducted for the Kerr brand of mini splits distributed in Canada by Kerr Controls. You can see the pictures here.
I was privileged to visit Kerr locations in Ontario, New Brunswick, Nova Scotia and Newfoundland last month and at each location they had a huge crowd for me to address…in fact, in Truro, Nova Scotia we had the biggest crowd in 2013 so far! So big that we had to change venues and conduct the class in a local hotel’s ballroom…it was like playing Vegas!
The following is from Kerr’s company bio:
‘In business since 1949, Kerr’s business has grown over the years from a humble beginning with the founder (and current chairman David Kerr Wilson) selling and servicing out of a milk truck. This start to Kerr Controls took place with the founder identifying suppliers around New York and selling throughout New Hampshire and surrounding areas along the route. When the business started taking off Dave established a presence closer to his home in Truro, Nova Scotia and expanded throughout Atlantic Canada from there’.
One of the pictures in the ‘gallery’ on my website shows David Kerr Wilson in his red ‘milk truck’ …this picture, along with the company’s mission statement, is displayed at every Kerr location.
My time in the Atlantic north of Canada was made especially productive and fun because of Serge Cormier of Kerr Controls. Serge is the Sales Manager at Kerr and was with me at each location…he was a wonderful asset to me while there and for Kerr and Kerr customers, he is an invaluable asset year round!
In the group of pictures from the Kerr classes are two pictures of an ‘eatery’ in St Johns, Newfoundland called ‘Long Dicks Sausage Emporium’. I want to stress that this establishment has nothing to do with Kerr but I just couldn’t resist taking a picture…I could resist eating there, as I thought submitting a receipt for expense reimbursement from ‘Long Dick’s’ might not be in my best interest!
The best way to contact Gerry
Just want to remind everyone that the best way to contact me is via email. I’m either driving or flying most the time, and when I’m not, I’m conducting classes, so the best way to contact me is via my email…I tend to answer emails when I’m in my hotel room at night so you have a much better chance of getting the quickest reply through email.
That said, I also need to remind everyone that if your question is related to a Comfort-Aire or Century mini split in the United States you must call ‘Technical Services’ in Jackson. MI at 517-787-2100 first and they will involve me if necessary.
If you are calling about a Comfort-Aire, Century or Kerr mini split in Canada please call Aiton’s Equipment at 888-744-2911.
I am glad to assist when I can but because of my schedule I often cannot reply promptly and I don’t want to disappoint anyone so it is best to call the above numbers.
See you all soon!
Should the ‘counter day’ go the way of the dinosaurs?
I have been meaning to write this article for years but I always figured someone else would get to it so I kept putting it off…well, no one did so here goes!
I have been convinced for more than a decade that the ‘counter day’ event at wholesale supply houses has been the biggest waste of time, effort and money for the manufacturer’s rep, the supply house…and maybe the contractor as well.
Let me start by asking this question…have you ever gone to a counter day and learned something? I mean reallylearned something about a product and / or application that you didn’t know before? Now, I’m sure there is an exception to every rule and someone out there has indeed had something other than a free lunch at a counter day but I think if we all were honest about it we would say that is the rarity and not the rule.
I worked with and for manufacturer’s rep agencies for almost thirty years and I’m going to break the code of silence about counter days and how reps see them.
Most reps see counter days as a ‘part of doing business’ or a ‘necessary evil’. ..I see it as an ‘unnecessary evil’.
Because most reps see the counter day experience as a waste of time and a free lunch opportunity they send their least experienced, ‘newbies’ to man these events. Think about it…you wouldn’t send your best guy / gal to an event that you believed to be a waste of time…would you?
Maybe, if you’re a small agency, you have no choice but to attend these events yourself and instead of doing something productive, (and potentially revenue generating), you end up spending the day talking to the other rep who is there and / or flipping burgers.
Let’s look at it from the contractor’s point of view…who does the installer / service company send to the wholesale counter to pick up material…most often the ‘Johnny’ of their crew. Now, for those of you who have attended one of my mini split classes you know who Johnny is…he is the guy on your crew that in a perfect world would NOT be on your crew. Johnny is the guy you pay on Friday and is broke on Monday…he is the guy who is constantly texting…the guy who has a few Budweiser’s for lunch and that you know smokes the ‘ganja’…his name may be Pete or Tim but you know who I’m talking about…Johnny. The reason Johnny is on your crew at all is because you need a second set of hands from time to time, a guy to run to the supply house for material and, frankly, he shows up which is always half the battle with employees.
So you send ‘Johnny’ to ACME Supply to pick up a ¾” ball valve, a stick of 1” PVC and cement and tell him to get right back to the job because you and the rest of the crew are waiting for this material to finish the job. Johnny heads off with all good intentions but you don’t see him again for two hours…why? Because Johnny is enjoying the free lunch being served at ACME that day for a ‘counter day’ event.
Yeah, while he’s eating three hot dogs and two burgers, Johnny will learn about the attributes of organic hand towels that will not only clean your hands but take paint off most automobiles.
The counter day is the HVAC & plumbing equivalent to the ‘time-share’ event where you and the Mrs. go to learn about a new condo community being built in Boca Raton, Florida and get a FREE toaster oven too! Now, for most of us, our time is worth more than a toaster oven and because we realize that relatively simple fact we would never be caught dead at a time-share event…but, there is a segment of our world that live for free toaster ovens. We wouldn’t waste our valuable time spending a Saturday in the Poconos with the likes of them so why would we go to the counter day at ACME and hang out with the likes of ‘Johnny’ and his other ‘helper’ buddies?
A little harsh? Maybe.
If ACME wants to have a BBQ lunch as a ‘customer appreciation day’ I’m all for it! Maybe even solicit funding for the event from manufacturers and their reps…but please stop the practice of disguising these events as ‘counter days’ and just call them what they are…a free lunch!
Top 10 states for HVAC careers
There is a great article detailing a study / survey by Emerson Climate Technologies which created a top 10 list of states with the best opportunities for HVAC careers. You can see the article at Contracting Business .com at this address:
I found some states which I expected to see on the list like Florida and California but some surprises as well like Ohio and Illinois.
Back in the day when I was just starting out it was popular for guys to head to Florida because it was seen as the ‘mecca’ of HVAC. The problem was everyone had the same idea and the market became flooded with techs and those who did find work also found the wages were substantially less than what they had in NY, NJ and up through New England.
Based on the article it sounds like California is the new ‘HVAC mecca’ and it does seem to hold promise for those who want a warm climate near the water…and who doesn’t.
Many of the top ten states made the list based on the training opportunities found within the state…such as Ohio. I just spent the entire month of February in Ohio and Kentucky and I can attest to their ongoing desire for training.
I also find it interesting that no New England states made the top ten, (sorry, but as a NY Jet fan I cannot consider NY & NJ to be in New England). I would be curious to know if the fact that New England is traditionally a hydronic market is the reason it didn’t make the top ten.
Check out RectorSeal HVAC accessory products
I recently had a dilemma with a mini split ceiling cassette condensate drain that was driving me nuts! As with all mini splits the drain connection was an odd metric dimension and I couldn’t figure what would easily connect to the drain fitting that was also readily available either at my local HVAC supplier or online.
I discovered that RectorSeal has a line of insulated flexible tubing in all kinds of odd diameters specifically for this application. You can see them all here.
Also check out their line of mini split condensate pumps here.
You can see me install the Aspen model ASPMAUNI in a Comfort-Aire mini split wall mounted evaporator in a new video I posted on my website. Go to the ‘Videos’ section and click on the video titled, ‘Mini Split Condensate Pump Install’.
Those of you who attend my classes know I like to use the phrase ‘it will get you out of a jam’…RectorSeal has what seems like an endless catalog of products that will ‘get you out of a jam’…and there ain’t nothin’ better than that!
Something I wanted to share with you…this has nothing to do with HVAC so bail now if you like
I was supposed to be in Columbus OH on Monday, February 5th but bad weather in Detroit didn’t allow it so I tried again the next morning. I took off from Stewart International in Newburgh, NY at about 6:30AM and for the first 15 – 20 minutes all was fine. It is at this point that I heard and felt a BANG but looked around and no one in the 3/4 empty plane seemed to be reacting so I thought nothing of it…with over 48,000 air miles under my belt in 2012, it just seemed to be literally a ‘bump in the road’.
About ten minutes after the BANG the captain came on the PA to inform us the landing gear had come down in a malfunction and we were no longer going to Detroit…he said we had plenty of fuel and they were devising a ‘plan’. I noticed we had lost serious altitude and were turning left and right rapidly. Another announcement informed us that we were diverting to JFK and the landing gear ‘would most likely stay down upon landing’.
About ten minutes out of JFK we were informed that even if the landing gear remained down it was likely the wheels were locked and thus this was now an ‘emergency landing’ and JFK was preparing a foamed runway and fire trucks, ambulances and police were awaiting our arrival. I turned on my phone at this point to text my wife what was happening.
A few minutes before landing we were given one last set of instructions…assume the ‘kiss your ass goodbye position’…(my words, not theirs, but you know what I mean).
We landed safely among a sea of emergency vehicles and were escorted to a remote location where we deplaned…all was well!
Here is the interesting part…at least I think so.
I always hoped that if I knew the end was eminent, that I could control my emotions. I didn’t want my last emotion on this earth to be fear. I wanted to go down smiling rather than pooping in my pants sort of speak.
Well, I am pleased to say that I passed the test! If that morning was to be the end I was cool with that…no fear, no nerves…texted Patricia that I loved her and I was good to go.
I know this may be strange but I’m weirdly comforted by the fact I was ready. This was not the result of any courage on my part, oh no…rather I think it is a benefit of age.
As we approached JFK I looked around the plane, the fear I saw in a young couple…literally shaking in their skin…and another young couple with a very new baby…that made me sad. I must say, one of the advantages of age is that in a moment like that there ain’t much I haven’t done…our daughter is grown, I know I would leave Patricia financially OK and the people I love know I love them. Youth, however, has not had the time to make mistakes and learn from them.
See you all soon!
Are your employees ‘like family’?
Do you tell your employees they are ‘like family’ to you? Has your boss told you that you ‘are like a son’ to him? If you answered yes, how did it make you feel?
I ask these questions because I have become increasingly convinced that this practice of equating one’s job environment to ‘family’ is not a good thing for either employer or employee. Unless you’re Tony Soprano, your family is your family and your work / business is just that.
I understand where the sentiment for this now common practice comes from…we all want to feel that we are an integral part of something…something that couldn’t exist and / or would be less if we were not involved. The problem with telling an employee he is ‘family’ or ‘like a son’ is that it diminishes one’s actual family.
I was at a sales meeting years ago for a predominant radiant floor heat manufacturer and during the course of the meeting one of their reps got up and gave a presentation about his company. I won’t give his name or his company but it is one of what I call the ‘mega-reps’ on the east coast.
This fellow had a video presentation of his facility and discussed the many product lines he represented and the significant investment he had in product inventory…frankly, stuff we have all heard a million times at sales meetings. The owner got my attention when he began to speak about his employees and the ‘culture’ within his agency.
Before I go any further, let me say that this rep was second generation in an agency that was started by his dad. I think this is significant to mention because this fellow actually did work with family and most of the people who now worked for him, (his dad had retired), saw this man literally grow up from a young boy to now, their boss.
As the speaker went through descriptions of key employees and their roles in the company, he ended by saying that he was not going to describe his company as a ‘family’…he said that each employee had their own family…he described his company as a ‘community’. I really liked that…a ‘community’.
Webster’s dictionary defines the word community as follows; ‘a class or group with common interests’.
I like that! A group with common interests…that’s what I want my company to be!
The familiarity that comes with true family usually does not make for good business. Think about this…how many HVACR contracting companies can you think of that were fragmented, (or worse), by dueling brothers? The trades are notorious for this phenomenon!
Now, don’t get me wrong, there are exceptions and we all can probably think of a company where the owner uses the expression ‘family’ when speaking about his employees and he / she truly feels a kinship with them…this is wonderful but probably not practical and certainly not typical.
We all know families that we would like to be a part of…Rockefeller comes to mind…and we all know ones that we are happy not to be a member. Communities, however, are generally choices we make willingly to belong to and to leave as our needs and interests change.
So, the next time your boss says to you, ‘you’re like family to me’, ask him if you are in his will and if you can have the keys to his 1969 Corvette Stingray this weekend…I suspect you will feel more like a citizen than a son.
Remember the HydroPulse boiler?
Where was the first condensing boiler offered in the US manufactured? Germany? NO…it was Dundalk, Maryland.
Where was the technology developed? Germany? NO…the technology for the Pulse combustion boiler was developed by a man named Thomas Kitchen who was a Canadian national. Mr. Kitchen sold his patent and technology to the HydroTherm boiler company of Northvale, New Jersey back in the mid 70’s.
I actually communicated recently with a nephew of Mr. Kitchen who works for Danfoss as a trainer up in Canada.
Pulse combustion technology actually dates back to the late 1800’s. It has seen many applications over the years…some good and some, well, actually evil. The Nazis used pulse combustion to propel the V1 rocket used to attack Great Britain the WWII. The V1 used a pulse jet engine for propulsion…it was nicknamed the ‘buzz bomb’ because of the distinct noise created by the pulse combustion process. I actually got the chance to see a real V1 when my wife and I visited the Imperial War Museum in Duxford, England some years ago.
Jump about 35 years ahead and it’s 1979 and the United States is smack in the middle of an energy crisis…people are waiting in long lines for gasoline and home owners are suddenly faced with higher utility costs. The time was right for a newfangled boiler that could boast efficiencies of 90% + that was fueled by natural gas or propane…and so the HydroPulse boiler by HydroTherm was introduced.
In 1979 I was seventeen years old…two years later I would join HydroTherm as a nineteen year old long haired, (some things haven’t changed), pimple faced kid who was looking for money to go to college as well as support his wife and child, (new wife since then, same kid).
The HydroPulse boiler was met with much excitement back in the day…HydroTherm’s moniker was ‘innovators in energy conservation’…and they were living up to the hype with the HydroPulse! HydroTherm engineers were being interviewed by Sue Simmons on ‘Live at Five’ on NBC New York television and an ad for the HydroPulse was featured on the entire back cover of Time magazine…it was the days of ‘wine and roses’ at HydroTherm.
HydroTherm was officially a ‘player’ in the US boiler market reaching #3 behind the likes of
Weil McLain and Burnham. They drew the attention of investors and speculators and were purchased by Penn Central…yeah, THE Penn Central!
It was the best of times; it was the worst of times.
Problems began to arise with the HydroPulse fairly early on in its inception. The earliest vintage Pulse boilers utilized a mechanical sequence timer that would engage the gas valve and ignition transformer with a mechanical timing device that looked like the insides of a cuckoo clock. If the timer malfunctioned and delayed the ignition sequence but left the gas valve open…once the ignition transformer did engage it was possible, (and it happened), that the combustion chamber now contained a double or triple charge of fuel…ignition took place and, well, let’s just say that the concrete base of the boiler now looked something like a shattered clay flower pot.
Another early issue was the blower fan. The HydroPulse was a sealed combustion boiler…no open flame and it took 100% of combustion air from the outdoors through small diameter PVC tubing and discharged the bi-products of combustion through small diameter CPVC tubing. The blower assembly was used to purge the combustion chamber of any gases from the previous combustion cycle and at the same time induce outside air into the boiler for the next combustion process. The problem with the blower was that it was in a pretty harsh environment sitting atop the upper air chamber with temperatures of 1800 degrees taking place in the combustion chamber not all that far below. Fresh outdoor air coming in would cause condensation on the blower…it was susceptible to precipitation coming down the air intake tubing and the result was a rash of premature blower failures.
The early HydroPulse had what in some cases was a fatal flaw, (fatal to the boiler that is), and that was upper chamber leaks. The Pulse boiler had essentially three components…the base…the heat exchanger…the upper air chamber. The combustion chamber was suspended to the upper plate of the heat exchanger which was a closed vessel…literally made of steel the same gauge as tank armament. In between the combustion chamber and the upper plate was a red rubber gasket.
Now we all know the purpose of a gasket…to prevent a leak…well, in the case of the early HydroPulse, the red rubber gasket actually was the cause of the leak…a fatal leak that could not be field or factory repaired because the heat exchanger was a sealed vessel.
For many, the early problems with the HydroPulse were too much to overcome and the boiler began to get a bad reputation in the trenches.
…and of course there was the noise.
Pulse combustion by its nature is a noisy process…remember the nickname of the V1 rocket?
The noise, in the end, was the final blow for the HydroPulse boiler. Those of us who hung in there with the boiler through its 27 year run knew that all the early flaws had been resolved along the way and by the end of its run the HydroPulse had finally lived up to its early hype and expectations…but alas, long term success for the boiler was not to be.
European condensing boilers began to flood the market in the 2000’s and they were silent…no noise whatsoever…and so was the last nail in the HydroPulse coffin.
I’m still a Pulse believer to this day…a Pulse boiler is the heat source for low temperature radiant floor heating in my shop here in New York, (you can actually see a picture of the system in the January issue of Contractor magazine, page 21, for an article I wrote). I own and operate PulseParts.com which is an internet based business for OEM Pulse boiler repair parts and through that business I offer technical support for the tens of thousands of Pulse boilers which are still out there chugging along, producing BTU’s like crazy at efficiencies still rivaling today’s new condensing boilers.
The HydroPulse boiler wasn’t perfect, but it’s a part of US hydronics history…a part that I’m proud to say I had a small part in and still do today.
Are you on LinkedIn? You should be!
Look, I’m the last guy who would ever recommend ‘social media’…LinkedIn is NOT social media’. It is a wonderful resource for business networking where you can ‘connect’ with others in your same industry…or in an industry that you are interested in.
Bottom line it works…I have connected with people and companies which ultimately became clients and that is invaluable! Yeah, you might see your high school girlfriend on there but chances are she looking for work…not to rekindle and old flame…and by the way, don’t think so much of yourself…she could care less where you are today.
I’m on LinkedIn so if you want to connect with me to get started then send me an invite…I would be glad to help you get started!
AHR EXPO / ASHRAE Show, Dallas, TX
I will be at the show on Tuesday, January 29, so if you see me floating around looking lost please stop and say hello!
See you all soon!
HAPPY BIRTHDAY ESPCO!
December 13, 2012 marks ESPCO’s second year and 2012 could not have been more exciting and busy…busy is good! Go to ‘About ESPCO’ to see a review of our 2012 activities…I have to admit it blows my mind!
Thanks to all who attended an ESPCO class in 2012 and to all our great class sponsors and training partners…you made it all possible!
If you’re not already a subscriber to Contractor then I strongly suggest you go to www.contractormag.com and sign up for a free subscription. Contractor calls themselves the ‘news magazine of mechanical contracting’ and you will find great articles on plumbing, piping, hydronics, radiant, tools, trucks and much more.
I have an article being published in Contractor early 2013 so sign up for your subscription now so you get your first issue…hopefully with my article!
Click on ‘Training Events’ to see our growing schedule for 2013. We have seventeen classes already scheduled starting in February and going through April and more will be posted as they are confirmed. ESPCO classes will be coming to a city near you in 2013 so please take a moment and register for a class today!
GEOTHERMAL…TO PRESSURIZE OR NOT TO PRESSURIZE…THAT IS THE QUESTION
A growing preference among geothermal installers is to create a non-pressurized system rather than the more typical pressurized.
Before we get too deep into this conversation lets define non-pressurized: to call a geothermal system non-pressurized is a bit of a misnomer…with the cover off the flow center canister, (I will explain what a ‘flow center’ is in just a minute), and no pumps running there is atmospheric pressure, 14.7 PSI, on the geothermal fluid.
Let’s go for a moment to my basic hydronics class where I talk about ‘head’ pressure as it applies to sizing circulators in a heating system. A column of water 2.31 feet high has a gauge pressure of 1 PSI thus 1 PSI = 2.31 feet of head
With this in mind, 14.7 PSI can support a column of water 34 feet high, (this is based on 100% water which has a specific gravity of 1):
14.7 X 2.31 = 33.957
We are going to come back to this equation at the end of our conversation because it is critical to remember when designing a non-pressurized geothermal system.
Pressurized is easy to understand for us ‘wetheads’…we have been creating and servicing pressurized hydronic heating systems for most of our lives. We can apply most of this knowledge to pressurized geothermal systems but the big difference is in the pressure itself…when we’re talking geothermal we ain’t talking 12 PSI.
Pressurized geothermal systems can have pressures such as the following:
winter = 50 – 75 PSI
summer = 35 – 40 PSI
idle = 40 PSI
The difference in the winter and the summer pressures is the expansion and contraction of ground heat exchanger GHEX tubing…in the summer time when we are rejecting heat into the ground the tubing expands and the pressure goes down.
Pressurized geothermal systems use ‘flow controllers’ which are prefabricated pumping stations of sorts that utilize fractional horsepower, wet-rotor type circulating pumps, (one pump for systems up to 3 tons and 2 pumps for systems greater than three tons). Flow controllers come with directional valves, (five positions), on both supply and return for ease of system purging.
Typically pressurized systems have the GHEX headers buried in the ground…this was done to limit the number and size of penetrations into the structure’s foundation bringing supply and return piping to and from the mechanical room.
This was a good thing but it posed disadvantages at the same time…mainly that you cannot segregate each loop independently with appropriate valving. The little fractional horsepower pumps on a flow controller cannot create enough flow to properly purge the entire ground heat exchanger, (2 feet / second), to remove all of the air from the system and as a result you need to use a flush cart which has either 1 ½ HP or a 2 HP pump. I plan on discussing flush carts in depth in a future newsletter but for now you can see a flush cart in use here, watch the video titled ‘Flush & Purge, Montgomery, NY’
Some other disadvantages of pressurized systems are: thermal expansion of the ground heat exchanger may cause a large enough reduction in system pressure to cause pump cavitation, (negative pump suction side pressure). This will result in the dreaded ‘callback’ to re-pressurize the system.
Another disadvantage to the pressurized system is that any air that was not removed from the system in the purge process will remain in the system.
So let’s talk non-pressurized; the best place to start is with the ‘flow center’ that I briefly mentioned earlier. A flow center looks a bit like a flush cart in that is has a cylinder where you can actually see the geothermal fluid…there is a removable cap so you can add fluid and introduce and maintain antifreeze levels very easily.
Here’s a killer advantage…you can use a tubular flowmeter to actually determine the system’s flow through the GHEX. The flowmeter slips onto a dip tube inside the cylinder of the flow center and you can direct the flow from the meter back into the cylinder or into a bucket or drain to remove system water to be replaced by antifreeze. You can see me using a flowmeter in an instructional video I posted on my website…click on the video titled,
‘How to Use a Geothermal Flowmeter’. The flowmeter is a great diagnostic tool that among other things, could identify a damaged loop.
Non-pressurized systems tend to have the loop connections inside the mechanical room, (manifold headers). Loops are valved so that each loop can be purged independent of the others allowing the small flow center pumps to do the job instead of a flush cart…another nice advantage!
You don’t think you got out all the air in the purge process…no problem! Non-pressurized systems will remove the air all by itself over time…nice!
Think about this one…let’s say you have a pressurized system that is leaking…what do you do? If you can identify which loop is leaking, (that may be tough and what if multiple loops are leaking), you may be able to abandon the damaged loop only if you have the loops valved inside the mechanical room, (not typical of pressurized systems). Maybe you dig up the GHEX but that is a needle in a haystack and if it is a vertical heat exchanger, well, as Tony Soprano would say…’forget about it’!
How about you simply convert that leaking pressurized system to non-pressurized? Think about it…a non-pressurized system is going to leak a lot less than a pressurized one…yes? Fluid levels can be easily ‘topped off’ periodically as needed by removing the cap of the cylinder of the flow center…brilliant!
A perceived disadvantage with having the header manifold inside the mechanical room has always been the concern over making multiple penetrations in the structure’s foundation to accommodate each loop’s supply and return. This concern can be addressed by simply making two larger penetrations or a ‘chase’ to allow all the pipes to come through one or two larger penetrations.
OK…let’s wrap this up.
Let’s go back to my comments about atmospheric pressure supporting a column of water 34 feet high. You need to consider this should you ever install a GHEX in land with a steep incline…think about it…if the GHEX was 34 feet above the mechanical room where the flow center is installed you will drain the ground loops into the mechanical room when you take the cap off the flow center…and this is NOT a good thing!
ADVICE I RECEIVED YEARS AGO FROM ONE OF MY HEROES / MENTORS
When I was in my twenties and still pretty new to this HVAC thing, (and even greener as a business person), I worked for and learned from one of the greats in the HVAC industry…Harry Eklof. I was one of a few young guys Harry had in his employ and he would tell us that “you have to make yourself recession proof”.
Now, on the surface that statement may seem overly simple because most of us in the service and install side of HVAC believe we chose a business, (either consciously or otherwise), that by its nature is recession proof…when times are good our customers have us install new equipment and when times are bad they have us repair their old equipment…either way we got a job!
Many of us have learned, the hard way, that when times are real bad like they are now, people do nothing and the next thing you know is you’re not recession proof and you’re taking it on the chin.
Harry and his contemporaries lived through the depression years so being recession proof to Harry meant diversification beyond your core business always trying to stay ahead of the curve and not being a market follower but rather a market leader.
As we look to a new year I share with you the wisdom of Harry Eklof…be recession proof…think outside the box and prepare yourself, your family and your company for better times because they are ahead for us…maybe not around the corner but there nonetheless. Keep learning and as a result you will keep growing…betting on yourself is the best odds you will find in this world.
I hope everyone has a happy and safe holiday season and a prosperous New Year!
See you all soon!