Geothermal heat pump: first winter results

MacLawn · May 12, 2015

I'm doing the water heater for sure! But, I've never heard of using a second water heater. My geothermal man just called a few minutes ago, and he said I could even do it in stages, install the ground loops first, then the unit! I was just wondering about that possibility yesterday! Oh, and he also assured me NO condensate drain inside the house! Whew. Great! That'd take a bite of the initial cost pain, but, if I can get a decent financing plan, I might just bite ye olde bullet. Have to talk with Ethyl when she gets home from out of town work...

fordmantpw · May 12, 2015

If you can swing it, go for it all at once (IMO). If you can't do it all now, just save the funds until you can. If you do it closer to the end of the year, you don't have to wait as long to get your 30% back from Uncle Sam.

The second water heater is just for storage. The theory is that the unit heats that water and increases the temp coming into your main water heater. If it is just for 2 people, a single water heater will likely suffice. We have 2 and I love it. The bad thing is, during spring and fall when the unit isn't running, we don't have as much hot water and have to spread our showers out a bit. You ever realize how hard it is to get kids to take a shorter or slightly cooler shower?

dodge man · May 12, 2015

The second water heater isn't really a water heater, just a tank. With ours, it looks just like our water heater, just no electric coils. I like to think of it as a preheater, the water in it get up to maybe 120 degrees, maybe a little less, when the geo is running. The water from this storage tank then goes into the water heater than into the house. If the geo is running a lot, this storage tank is filled with the semi hot water, if the geo isn't running, then its full of cold water. My wife likes HOT water so our water heater is turned up to about 160, but if you run your water heater cooler, it would use less electricity.

fordmantpw · May 12, 2015

dodge man said:
The second water heater isn't really a water heater, just a tank. With ours, it looks just like our water heater, just no electric coils. I like to think of it as a preheater, the water in it get up to maybe 120 degrees, maybe a little less, when the geo is running. The water from this storage tank then goes into the water heater than into the house. If the geo is running a lot, this storage tank is filled with the semi hot water, if the geo isn't running, then its full of cold water. My wife likes HOT water so our water heater is turned up to about 160, but if you run your water heater cooler, it would use less electricity.

And I thought my wife liked HOT water! Ours is at 150.

We actually have 2 identical water heaters. It was actually cheaper that way than buying a storage tank (go figure!). Our second one just isn't wired in, but could be at any time.

truckdiagnostics · May 12, 2015

Maclawn, I am going to see if I can explain the difference in the water furnace geothermal units that they offer. There is the unit that we have in our shop it makes hot water and chilled water, then there is a separate pump that runs to make hot water only when the unit is running. If the unit did not run, no hot water and then the heating element in the electric hot water heater would take over. This basic unit is basically there building block.
The next type they have is the above and they basically stick an air handler on top with a water coil. That is how they get you your forced air heat. They then put an electric coil in for back up heat in the plenum along with the water coil.
Next unit hey have is the above set up to make all your domestic hot water and water for in floor hydronic heat. In this unit they add a water to water ex-changer to everything I just listed above.
Geothermal heat if installed correctly can heat everything no mater how cold it is! On a 5 ton unit we heat 3,000 square feet on forced air. Then heat the garage floor to 45 and all our domestic hot water. I unplugged the back up electric heat, so the geothermal heats everything. How i am doing it is in zone. It heat the domestic hot water first, then forced air then garage floor. In the am the air temp will drop 2 degrees as three people are showering. Then the forced air catches up. garage floor temp will drop as door opens twice. depending on out side temp will depend on how long it takes to catch up. With the last zone being the garage, I have never had the temp go be low 32.
What are you heating with now? It sound like you already have an air handler and use force air. Why not leave it, use it for back up and add a water coil to the plenum. Use the 5 series(500R11). Then when you get the money add a water to water ex-changer. You can do this and use your existing hot water heater? Depends on current size. The dilemma you have is you have to find someone will and knowledgeable to install it this way. Good installer should be able to figure it out. Depending on how handy you are, i'm no rocket scientist. Basically, they did what i did and made it there top of the line all in a neat package unit.
This next question you need to ask you installer, "if the compressor goes bad can you replace it" if they can or say they don't look for another installer. When I installed ours 15 years ago no one had a clue and there was only one installer that listened to what I had to say, said it was possible and was willing to do what I wanted. When it is cold out that compressor will kick in and not stop running it just sites there and switches between zones. We are on propane over the last 15 years we have saved fortune. I have over simplified things because there everything in one basket unit, has some assume controls. :2cents:

dstig1 · May 13, 2015

I read the horror stories of people having to replace major portions of the units, some repeatedly. Install looks to be on the outer edge of what normal humans can do as you really want a pump unit to fill and purge properly. I take on most everything, but this sounded beyond even my limits, so no DIY. I then got quotes. The prices were insane. And no great rebates at the time I was looking (I think there were some, but certainly nothing amounting to 80% of the cost as one posted noted). Part of this may be due to climate. Up here it gets darn cold. Geo heat pumps seem better suited to cooling than to extreme heating, but that is more of an inference than a fact on my part. Run the numbers as best you can for yourself. When I did it came back "no way." Others here have different stories. I was expecting great things from them, but it didn't pan out for me. There are a lot of factors at work in running the numbers, so that may have been the issue here.

Henri88 · May 13, 2015

fordmantpw said:
If I lived in the areas where it was extremely cold for extended periods of time in the winter, I probably would not go geo.

Would you be kind enough to elaborate on this statement? We are planning are new house in a year or so with Geothermal, water well and a hydronic system ''slab on grade'', and of all the research I did in the last 3 years this is the first time I read someone suggesting that (geo in extended cold period would not be recommended.) Don't get me wrong, I am not challenging your statement, just want to learn more from experience people.

Redneck in training · May 13, 2015

We built our house in 2004. We heat and AC about 2400 sqft to 72F and we heat only about 1400 sqft garage to 50F. Both the house and the garage have floor heating. The house has "high pressure" (Unico) system for AC. The outside loop is in our pond. I don't remember what was exact cost but it was around 30k - 35k. We did a lot of mechanical installation such as fan coil and ducting DIY. We used to have two electric meters. One for the heating and one for total consumption. Our normal electric rate is 11.3 cent/kWh but we used to have discounted rate in a heating season 3.5 cent/kWh (in 2004) that was gradually increased to 5.5 cent kWh (in 2012) and taken away two years ago. Our heating bill in the coldest month (January) used to be less than 100 USD. The geothermal heat pump is Waterfurnace 4.5 kW unit (5 ton).

We added a shop building in 2012 where we used Halcyon mini split unit with two air handlers. $3500 installed. Conclusion: If I would build our house today I would use mini split unis and then add PV system to power it all up and there would be money left for nice trip to overseas vacation.

truckdiagnostics · May 13, 2015

Henri88 said:
Would you be kind enough to elaborate on this statement? We are planning are new house in a year or so with Geothermal, water well and a hydronic system ''slab on grade'', and of all the research I did in the last 3 years this is the first time I read someone suggesting that (geo in extended cold period would not be recommended.) Don't get me wrong, I am not challenging your statement, just want to learn more from experience people.

If it is installed correctly it will be fine. I know guys that have it installed in Saskatchewan, works fine and back up heat never comes on. If it is not working fine, the installer did not do something correct. can be a bunch of things, around here they did not size the loop correct or bury it deep enough. On the shop unit I have had inlet temps at 40 degrees and still able to get 6 degrees out of it. last year I had return water temps below 32 degrees. Not real cost effective at those temps but it worked. Getting everything sized right for your area is huge. I'm not a fan of an open system if that is what you are getting at with geothermal water well. Steve

Henri88 · May 13, 2015

truckdiagnostics said:
If it is installed correctly it will be fine. I know guys that have it installed in Saskatchewan, works fine and back up heat never comes on. If it is not working fine, the installer did not do something correct. can be a bunch of things, around here they did not size the loop correct or bury it deep enough. On the shop unit I have had inlet temps at 40 degrees and still able to get 6 degrees out of it. last year I had return water temps below 32 degrees. Not real cost effective at those temps but it worked. Getting everything sized right for your area is huge. I'm not a fan of an open system if that is what you are getting at with geothermal water well. Steve

Thanks, the info that I got pretty much collaborate what you just said. As for an open system, there are a few reason for going in that direction. The property is mostly solid rock so horizontal loop is out of the question and tests that were made not far from where I'm building has shown to have more than enough water at 125 feet. I like the close system as it should be less cost maintenance, but the open system should be a little more efficient which in my neck of the wood is important.