Geothermal Performance Issues and Questions

1. Is your geothermal system working properly?
   
2. Am I getting the most bang for my buck?
   
3. Is the payback timing less then it should be?
   
4. Is this thing suppose to run this much?

These are just a few of the questions that come up with geothermal installations. Sad thing is, some of these and other questions come up after the unit is installed. Sales people should cover all the choices and make sure the buyer understands them before the system goes in. Geothermal units have far more options then any other conventional heating, cooling systems. Folks thinking of buying into this wonderful technology need to understand the options and what each of them offer in performance and comfort.

For those that already have your units and have issues and questions, how about posting them in this thread and lets talk about them.

1. Is Your geothermal system working properly?

Yes I beleive it is.

2. Am I getting the most bang for my buck?

Compared to the heating cost of convential systems I'm getting a pretty good bang for my buck. Replacing my 19 year old system will most certainly increase my "Buck Bang" but it still has a little more kick left in it. Unless its horribly inefficent compared to newer 2 stage system, I rather just keep it to it dies.

3. Is the payback times less then it should be?

I'm the 2nd owner of the house/system. I don't know that the original cost was but comparing the size of the house with heating bills to smaller or simular sized houses I would guess it's living up to it's hype.

4. Is this thing suppose to run this much?

I've never noticed the system run all the time. I really haven't paid a lot of attention to how much it runs, only the electric bill at the end of the month. My system does not have backup heat, so installing a programmable temperstat was proably a good idea. I initially feared that with having the system turned off for extended periods at night when its 10 or 20 degrees out would risk the discharge pipe freezing, but my fears were unfounded. I examined the discharge pipe during the coldest weather and there was no ice build up anywhere around where it was dumping the water. I had expected the water to form ice around the discharge pipe and for the frozen ground not to absorb the water, there by forming a pond of water. There was no water buildup, I had trouble finding any wet ground at all 2 or 3 feet from the discharge pipe.     

Great idea! I'm going to defer my answers because time is short, but in general, there seems to be very little post-installation performance monitoring in the geo world. Given current fuel prices, it is entirely possible that even a poorly installed and underperforming system could be saving money when compared to an oil or propane system.

Also, Eric, did you get the email I sent through the site a few days ago? I suspect not since I've sent some others that haven't gone through - I'm not sure if the system is broken or if I'm doing something wrong. Could you let me know your address or send me a note at braman at braymo dot net? Thanks.

Hello,

I have been meaning to write about my experience with a closed loop geothermal system for quite some time. This thread provides a good opportunity to do so.

I live in South East PA. I had a closed loop Climatemaster Tranquility 64 system installed in my house around Thanksgiving of 2007.

Before the installation of Geothermal system, our house had a 100,000 Btu Bryant propane furnace with a reported efficiency of 93%. I believe the furnace was installed when the house was built 17 years ago. Sheet metal ducts in the house were designed for a 5 ton system but the air conditioning unit and blower were in keeping with a 4 ton system.

When I started looking into a geothermal system, I did my own load calculations which were later verified independently by the contractor who installed my geothermal system. Heating loads for my house were in the range of 60,000 – 75,000 Btu/hr depending upon the assumptions made for enclosure infiltration and insulation in the basement. Cooling loads were in the range of 35,000 Btu/hr. Contractor and I agreed to size the system to the heating loads and hence the 64,000 Btu heat pump. My house is roughly 3,700 sq ft of living space. I have an unheated basement.

The heat pump uses two closed loops connected in parallel – each loop is 380 ft deep comprising 1 ¼” pipe. The loop uses two Bell and Gossett circulating pumps, that came packaged in a panel assembled by a company in Indiana – Flow Center Inc.

1) I believe the system is performing correctly. In January and February I did have a problem with the heat pump shutting down on very cold mornings – always happened around 6:00 am in the when the external temperature was 20 F and below. It turns out that the installer had forgotten to clip the jumpers on the control board – these need to be clipped for cold weather performance where the loop temperature can get close to freezing. That problem was fixed.

2) I am definitely experiencing significant energy and cost savings, since the system was installed. During previous years, my house would roughly use 800 – 1000 gallons of propane/year. I own my own propane tank and last year I paid on the average $1.80/gallon for propane. This year the price for me would have been $2.40/gallon. This year during the months of January, February and March I am averaging about 1500 KWhr/month of electricity. Last year at the same time I was averaging 750 KWhr/month. So the heat pump is using 750 KWhr/month to heat our house. With an all electric rate of $0.073/KWhr (above 600 KWhr), we are only using $50 -$60/month to heat our house. That is great savings for us and better than what was predicted from GeoDesign calculations by Climatemaster. Whether the system has been optimized and is performing at its best, I cannot say. I hope it is but I do not have enough information to say that for sure. I do wonder about the loop temperatures and whether the average heat transfer coefficient in the geo loop is good enough.


3) If the energy/cost savings continue, and I do not have any mechanical problems with the system, I would be very happy with the rate of return on the system.

4) My system does not run for long periods of time. We keep our house at 64 F. At times, I wish it would run longer at a low stage so that it would not cycle as much. Our Honeywell Vision Pro thermostat is set for 3 cycles/hr.

I hope this information helps.

Regards,

VK

Eric,

Thanks for your input. The Climatemaster manual describes the high pressure interlock just as you described it in your note. They also state that if antifreeze is used in cold zones then the two specific jumpers need to be clipped. I know that one of the installers did call Climatemaster for technical support.

I know that the installer did use glycol (either ethylene or propylene; not sure which) as the antifreeze. I am not sure what was the concentration of the glycol in water and hence do not know the freezing point of the solution in my loop. I will ask him about that.

Thanks for the "heads up".

Regards,

Vivek

Climate Master heat pumps come from the factory set to not operate with incoming water temps lower that about 40 F. There is a jumper provided that the installer can clip if antifreeze has been added to the system. With the jumper clipped, the units will then work with incoming water temps down to about 20 F.

This is a great feature as it protects heat pumps from damaged heat exchangers.

Was the orginal saving estimate based on 1.80/gallon or propane? I beleive that somehting many people forget, that the cost of fuel is going to continue to raise making any pay back estimate higher than it will be. That's a big different in heating costs, a 75% increase in heating cost in one year?

I really have little sympathy for those big SUV owners that are crying over what it costs them to fill up there gas tanks. Automotive manufactures took a hit on SUV sales when prices increased from $1 to $2, but once people got used to the $2 gas prices after while, SUV and big truck sales surged again, now with gas expected to hit $4 to $5 by summer the sales of bigger vehciles is suffereing again. Only time will tell if America will get used to $5 a gallon gas and start the cycle over again. I would like to think they have learned there lesson, but some how I doubt it. Anyway Im getting way off topic here. .   
Based on the current $2.40/gallon figure for fuel, with the operating cost savings, when is the break even point? What did the system cost you to install?

TECHGROMIT,
MOST OF US ARE NOT FANS OF "TURNING OFF" OR DIALING DOWN HEAT PUMPS BECAUSE OF RECOVERY COSTS. AS YOU POINT OUT IT IS NOT AS CONSEQUENTIAL DUE TO THE LACK OF A RESISTANCE COIL IN YOUR SYSTEM, BUT GENERALLY SPEAKING YOU'RE BETTER OFF TO LEAVE IT ALONE OR MAKE MINOR ADJUSTMENTS.
VK,
I HAVE FOUND MORE THAN ONE CLIMATEMASTER NOT INSTALLED CORRECTLY AND RUNNING ON SECOND STAGE ALL THE TIME. I ALSO AGREE WITH GEODEAN THAT CLIPPING THE JUMPER WAS PROPER AND DID NOT LEAVE THE UNIT UNPROTECTED. CLIMATEMASTER LIKE MOST MANUFACTURERS DOES REQUIRE SOME TRAINING BEFORE ALLOWING PURCHASE OF THEIR EQUIPMENT, BUT WE ALL FORGET THINGS FROM TIME TO TIME.
JOE

Hello, TechGromit,

I am not sure if I understand your question regarding cost savings - maybe I was not very clear in writing about my experience.

I total electricity usage/month for Jan, Feb and Mar 2008 has been 1500 KWhr. Last year I was averaging about 700 to 750 KWhr and at that time I did not have a heat pump. Therefore, the heat pump(on the average) is consuming 750 - 800 KWhr/month. Hence my energy usage for heating is about $50-$60/month.

I am further estimating that over the a five month heating period I would average $300. I am also hoping ( no data yet) that during the cooling months I will save some money because my new heat pump will be way more efficient than my 17 yr old A/C. Hence, effectively I am going to spend roughly $100-$150/year more on electricity than I had to in previous years.

But I now do not have to pay as much for propane. If I use current propane prices and assume a 1000 gallon usage/yr, I would have used $2400 over the entire year. I also estimate that about 150 gallons/yr goes toward running my tankless hot water heater.

So roughly speaking, at current propane prices, I am saving about $2000/yr.

I paid $23,000 to have the system installed - this includes a 10 yr parts and labor warranty. Note that in order to estimate the payback time, one needs to know that I needed a new heating system anyway. I was being quoted any where from $11,000 to $13,500 for an air to air heat pump and a high efficiency propane system.

At 8% rate of return, my payback time is 8 yrs for $12,000, 12 yrs on $15,000 and 10 yrs on $10,000 investment.

I hope this helps.

Joe,

I wish I knew how to find out when my heat pump runs and first stage and when it runs in second stage. I am not one for relishing bells and whistles in the products I buy but it would have been helpful if Climatemaster has installed indicators to show stage operations, Entering and Leaving water tempertatures and estimated COP.

Regards to all,

VK

I believe the day will come when you're going to wonder if you'll be able to get oil or propane at all. I guess the payback will be really good then when you have to compete with every other human on the planet for whats left.

Second stage on the compressor is controlled by the settings on the thermostat.  It shouldn't be a mystery at all. What kind of thermostat do you have?  Most thermostats have a setting that says engage second stage after first stage runs for so many minutes.