April 2012 ESPCO Newsletter
How do you know if your geothermal system is performing to specification?
I had the pleasure last month to travel to Jackson, MI. to participate in a Comfort-Aire geothermal class conducted by Leon Cogswell and Bob Sycks of Heat Controller / Comfort-Aire. This was a unique opportunity for me to observe and learn from Bob who has been conducting the Comfort-Aire geothermal classes for some time and recently announced his retirement to be effective later this year. Bob is one of the those special trainers who after being in his presence a short time you sense his brilliance but at the same time has a wonderful ‘every man’ way of speaking that allows him to put forth what can be very complicated material in an easy going, comprehensive manner. There is a geothermal class scheduled for May 16 – 17, 2012 in Jackson and I can’t encourage you enough to take what may be this last opportunity to learn from the best…Bob Sycks.
Leon Cogswell, Heat Controller Sales Manager, has been assisting Bob with the class for the past couple years now and he brings his extensive knowledge of geothermal as well as practical experience in actual installations to the party. Leon and Bob conduct butt and socket fusion welding demonstrations and each attendee gets the opportunity to participate.
I have added pictures of Bob and Leon in action on my website in the ‘gallery’ under the heading ‘Comfort-Aire Geothermal Class, March 13 – 14, 2012, Jackson, MI.‘ Check out the great training facility these guys have created in Jackson, MI. not only for geothermal but for the entire Heat Controller product offering. It was an honor for me to have Bob and Leon ask me to participate in their class…it was like playing the ‘big room in Vegas’!
I want to share with you my portion of the class which pertained to ‘system performance checks’.
It is essential that once the system installation is complete that a performance check is conducted to verify that the system (and equipment) is performing as designed. A water side performance check requires NO refrigeration gauges but rather the use of pressure and temperature gauges located at the inlet and outlet of the heat pump’s coaxial heat exchanger, (where the water exchanges heat with the refrigerant).
We need to calculate the heat of extraction / rejection of the system water to the earth. My good friend, John Barba, is famous for the line, “you gotta do the math” and as one who freely admits to being ‘mathematically challenged’, I would always cringe when there was math to be done…but this process is painless and very necessary.
Heat of extraction refers to the amount of heat extracted from the water through the refrigeration effect and can be compared to the design data of the equipment manufacturer for a performance check.
Let’s go through a quick four step procedure in preparation for the performance check:
- Always start up the new unit in the cooling mode…this will expand the Ground Heat Exchanger (GHEX), tubing as it will be rejecting the heat to the ground in this scenario.
- Disconnect the Hot Water Generator (HWG) / desuperheater pump before beginning the performance check…you do not want the HWG to influence the measurements you will be collecting.
- Allow the system to run for at least 15 minutes achieving ‘steady state’ conditions before taking measurements.
- Begin to fill in the numbers for the Heat of Extraction equation…here is the equation:
HEAT OF EXTRACTION (BTUH) = WATER DELTA T X FLOW (GPM) X FLUID FACTOR
The system should perform within 90% of the unit’s specified performance.
Let’s review some of the formulas we will be using through this process:
DELTA T is the temperature difference between the Entering Water Temperature (EWT) and the Leaving Water Temperature (LWT).
DELTA P is the pressure differential between the EWT and LWT
Entering Water Pressure (EWP) – Leaving Water Pressure (LWP) = Delta P
Delta P converts to GPM (gallons per minute) using the pressure drop table for the equipment at the correct EWT, (see manufacturer’s product performance data sheet).
FLUID FACTOR is the ability of a solution to transfer heat in a certain period of time.
The fluid factor of a 30% propylene glycol mixture is 483
The fluid factor for a 25% ethanol mixture is 515
The fluid factor for water is 501
Okay…let’s go through an example:
We will use the Comfort-Aire model HTV036 1200 CFM / FULL LOAD as our example. Our EWT is 50 degrees and out LWT is 41 degrees. The EWP is 43.1 PSI and the LWP is 40 PSI
We can easily calculate the delta T is 9, (50 degree EWT – 41 degree LWT = 9), so let’s plug that into the equation:
HEAT OF EXTRACTION (BTUH) = WATER DELTA T X FLOW (GPM) X FLUID FACTOR
HEAT OF EXTRACTION (BTUH) = 9 X FLOW (GPM) X FLUID FACTOR
So now we would need to refer to Comfort-Aire’s performance data sheet for the model HTV036 1200 CFM / FULL LOAD. You can see it in the ‘Engineering Design Guide’ on page 16 at this address:
http://hci.heatcontroller.com/lib/HTV-HTD-HTH%20Design%20Guide%202-23-12.pdf
We know the EWT is 50 degrees so we find that on the first vertical column. We also know that our Water Pressure Drop (WPD) is 3.1, (43.1 EWP – 40 LWP = 3.1 PSI), so we can find that in the third vertical column marked WPD / PSI moving downward until we hit the 50 EWT section. Now move horizontally to the left to find our GPM is 6.8 in the second vertical column. Let’s add that to the equation:
HEAT OF EXTRACTION (BTUH) = WATER DELTA T X FLOW (GPM) X FLUID FACTOR
HEAT OF EXTRACTION (BTUH) = 9 X 6.8 X FLUID FACTOR
We are making progress!
The last part of the equation is the fluid factor. We are using a 30% propylene glycol mixture in our GHEX so we know our fluid factor is 483…lets add this final number to the equation:
HEAT OF EXTRACTION (BTUH) = WATER DELTA T X FLOW (GPM) X FLUID FACTOR
HEAT OF EXTRACTION (BTUH) = 9 X 6.8 X 483
The calculated HEAT OF EXTRACTION = 29,560 BTUH
Going back to the performance data sheet we can now move horizontally to the right and locate the vertical column marked ‘HE’ and see that the specified heat of extraction for this piece of equipment is 29,400 BTUH. The calculated heat of extraction is well within the specified HE, (in fact it can’t get much better), and so we know our system performance, at least on the water side, is in great shape!
Next month we will look at the refrigeration side of the system and check our system performance there.
Thermostat and high limit control museum in Salem, Oregon
I had the incredible pleasure of conducting mini split classes for the Comfort-Aire people at six Johnstone Supply locations in the Pacific Northwest last month. On my stop at the Johnstone in Salem, OR. I met Glenn Crossway who has the most incredible collection of antique thermostats and high limit controls that I have ever seen and it is on display at the Salem Johnstone. I have posted some pictures of the collection on my website in the ‘gallery’ under the heading ‘Johnstone Supply, Salem, OR. antique thermostat and high limit collection‘.
I have collected similar vintage thermostats myself but my collection can only be described as ‘modest’ compared to Glen’s.
Glenn is a dead ringer for the guy named Jack on the reality show ‘Gold Rush’…luckily he does not have a similar voice, (that guy Jack has the most grating voice I have ever heard on a male human being). If you’re ever in the neighborhood of Salem, OR. you have to stop in and see Glen’s collection in person…great stuff!
New class dates posted on the website
Here are a few new dates for upcoming classes:
SUBJECT: Mini Split Air Conditioning & Heating
DATE: Thursday, April 26, 2012
CLASS SPONSORS: Comfort-Aire / Heat Controller & FW Webb
LOCATION: FW Webb
101 Jefferson Blvd.
Warwick, RI 02888
CONTACT: 401-463-8339
SUBJECT: Mini-Split Training
SPONSORS: Heat Controller / Comfort-Aire and FW Webb
DATE: Thursday, May 3, 2012
TIME: 5:00 – 7:30PM
LOCATION: FW Webb
3 Highland Ave
Queensbury, NY 12804
CONTACT INFO: 518-792-1316
SUBJECT: Mini-Split Training
SPONSORS: Heat Controller / Comfort-Aire and FW Webb
DATE: Monday, May 14, 2012
TIME: 5:00 – 7:30PM
LOCATION: FW Webb
737 Bank St.
Waterbury, CT. 06708
CONTACT INFO: 203-574-5959
SUBJECT: Mini-Split Training
SPONSORS: Heat Controller / Comfort-Aire and FW Webb
DATE: Monday, May 21, 2012
LOCATION: FW Webb
43 Sword St
Auburn Industrial Park
Auburn, MA. 01501
CONTACT INFO: 508-757-9322
SUBJECT: Mini-Split Training
SPONSORS: Heat Controller / Comfort-Aire and FW Webb
DATE: Tuesday, June 5, 2012
TIME: 5:00 – 7:30PM
LOCATION: FW Webb
2409 Portland St.
St Johnsbury, VT. 05819
CONTACT INFO: 802-748-8101
Music
I haven’t written a ‘music’ section in recent newsletters simply because I have had so many other things to talk about but this month I had to make room to tell you about the most incredible guitar shop that I visited in Eugene, Oregon. The name of the shop is McKenzie River Music. My friend, Tim Trantham (Comfort-Aire rep) took me there.
I have been to most of the renowned guitar shops in Manhattan, (30th Street Guitars, Rudy’s, etc.), and McKenzie River rivals any of them. I couldn’t believe the offering of vintage acoustics, electrics, resonators, Dobros, ukuleles and mandolins all on display and the visitor are encouraged to sit and play anything he / she might fancy…what a joy!
In my modest collection, two of my prizes are a 1926 Martin ukulele and a 1956 Martin style A mandolin…McKenzie River had at least three of each!
You can check out McKenzie River Music’s website at this address:
See you all soon!