November / December 2013 ESPCO Newsletter
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 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.