Hello! I am having issues with our new geothermal system installed in new construction in mid-2015 and am hopeful you all can provide guidance on where to even begin. Please forgive if I don’t give all the information. I am not well versed in this and since our contractor got fired I have had to teach myself via the internet.

-Installed by Geothermal contractor who was in the HVAC business 40 years, geothermal since 1993. References from completed projects saying he did a good job, etc.

1) Boone, NC

2) We were not given this information and I do not see it in my GeoDesigner printout. I have a ~2100 SQ FT home with two stories, the downstairs being a “basement” sort, built into a hill. Half the downstairs is an un-heated garage, concrete block frame while upstairs is wood framing.

3) Two pumps, less than 1 year old:
-Climatemaster THW010AGY01CSCS water to water heat pump
-Climatemaster TES026AGD02CNNS forced air heat pump

4) Two vertical wells dug to 400 feet.

5) Costs: 10.27¢ per kWh in summer & 9.93¢ per kWh in winter
-Total kWh December: 1694
-Total kWh November: 1178

6) I do not have the EAT/LAT as all our measurements have focused on the radiant unit. Can get if necessary. Noticed last night the air seemed cool.

7) Forced air unit has 4 pipes: Water in, water out, HWG Out, HWG in. I will include all of them:
HWG In: 110, HWG Out: 112, Water in: 59, Water out: 74

8) 100% geo for heating and cooling

9) The installer was fired by the company halfway through the project and has had no interaction with it since

10) Projected costs: — The contractor based this off Raleigh, NC which is significantly different climate wise than where we are located, but am including it anyway:
-Climatemaster TES: $83 heating cost, $266 hot water cost, $437 total cost, $36 monthly cost
-Climatemaster THW: $133 heating cost, $312 hot water cost, $595 total cost, $50 monthly

10) Actual Costs:
-October: $150 total electric bill
-November: $150 total electric bill
-December: $190 total electric bill

We have geothermal radiant floors as well as forced air. The issue we are running into is neither system can heat the house independently, and even together they struggle when it is in the teens (F) outside. The radiant floors, we’ve found out, were installed with drop-clip installation between joists instead of gypcrete or subfloor panels which is not ideal. We requested gypcrete initially but were told the drop-clips were a better product. We should have trusted Google instead of going along with it. Once it drops below 30 outside, the radiant system can not heat the house alone, especially our living room with vaulted ceiling. The downstairs has in-slab radiant and heats flawlessly with the radiant regardless of temperature outside so it seems related to the installation of the radiant upstairs and not the unit itself. So at this point we might have to settle for the fact it will never work as we were promised since it’s drop-clip and not gypcrete or subfloor tubing. This is incredibly depressing to me as we had hoped to use it as our only heat source and put a lot of money into it.

The geothermal forced air was only intended to be used for cooling in the summer on the rare days we needed it, but when we tested it yesterday it can not warm the house up with below freezing outdoor temperatures and we don’t know why. The living room (vaulted ceiling) was 63 degrees, set to 71 this morning after an evening running continuously. The bedroom was 67.

We are not sure where to start with why the forced air system can’t heat the house. The situation is a mess since we’re dealing with a company that fired the original contractor and then got bought out by another company. Their current “geothermal specialist” said we could fix the radiant issues by putting blown-in insulation into the space surrounding the tubes (vs. the batted R30 in there now) which is a terrible idea so I’m wary of trusting what he has to say.

Does anybody have ANY ideas on where to start with figuring out why our forced air system can’t heat??

Posted By MKer1 on 06 Jan 2016 02:57 PM

7) Forced air unit has 4 pipes: Water in, water out, HWG Out, HWG in. I will include all of them:
HWG In: 110, HWG Out: 112, Water in: 59, Water out: 74

Just a homeowner here... Are you certain of the water temps? In heating mode, the leaving water should be cooler than the entering. Do you know if your forced air unit has auxiliary heat strips? If temps are in the teens, that's when they would most likely need to come on.

Consider finding another local geothermal installer to diagnose it. In the mean time, check that the thermostats are set correctly.

Posted By stickman on 06 Jan 2016 09:00 PM

Posted By MKer1 on 06 Jan 2016 02:57 PM

7) Forced air unit has 4 pipes: Water in, water out, HWG Out, HWG in. I will include all of them:
HWG In: 110, HWG Out: 112, Water in: 59, Water out: 74

Just a homeowner here... Are you certain of the water temps? In heating mode, the leaving water should be cooler than the entering. Do you know if your forced air unit has auxiliary heat strips? If temps are in the teens, that's when they would most likely need to come on.

That's my bad! It said "heat on" but it was at the correct temp so it might have been cooling down. I just went and measured when it was actively working and got:

Water in: 50, Water out: 43, HWG In: 114, HWG Out: 118

I don't know about auxiliary heat strips, honestly. I believe our water --> water unit has some sort of electric backup but I'm honestly not sure if it DOES or if the water --> air unit does.

Posted By jonr on 06 Jan 2016 09:46 PM
Consider find another local geothermal installer to diagnose it. In the mean time, check that the thermostats are set correctly.

I wish there were more to consult, I'd have them out here last Tuesday :-) We talked with an engineer who's two hours away and he's the closest one. There's a local company that just started doing Geothermal & radiant and we might give them a call, but they definitely haven't been doing it for years.

The model number for the W to W should have a B or C as the second letter.

The Water to Air looks like a split system, air handler separate from compressor unit. Is ductwork/air handler in unconditioned attic space?

I am guessing the basement ceiling is finished, that's why they say to blow in cellulose. Taking down the ceilings to change the radiant tubing from clips to aluminum plates that make good contact to the subfloor would be my suggestion. What type of floor coverings? Carpet is an insulator.

$190 total electric bill, meaning all lights, dryer, stove ect. doesn't sound terrible. How do you make hot water?

CJ

Posted By ChrisJ on 07 Jan 2016 10:17 AM
The model number for the W to W should have a B or C as the second letter.

The Water to Air looks like a split system, air handler separate from compressor unit. Is ductwork/air handler in unconditioned attic space?

I am guessing the basement ceiling is finished, that's why they say to blow in cellulose. Taking down the ceilings to change the radiant tubing from clips to aluminum plates that make good contact to the subfloor would be my suggestion. What type of floor coverings? Carpet is an insulator.

$190 total electric bill, meaning all lights, dryer, stove ect. doesn't sound terrible. How do you make hot water?

CJ

I took the model # for the W to W system off the unit itself, I'm pretty sure it's THW but I'm also a novice so I could be wrong. You can find info about it here: https://www.climatemaster.com/downloads/EP017.pdf

The water to air is a split system, yes, with the air handler unit in the attic space.

Basement ceiling is a living space and is finished with drywall and has R30 insulation in the ceiling as well. The company had suggested taking out the R30 batting and putting in blown in insulation which didn't make much sense as the blow-in would have settled between the drop-clips and the upstairs making it harder to heat. Both floors have tile throughout.

The major concern with it already being $190 is that it hasn't been cold, really. We had a 70 degree Christmas which was super odd. We haven't seen nearly the amount of cold that we should so the bill if we had would have been staggering.

Good question about the hot water. The Water to Air unit has HWG pipes going in and out of it, but the Water to Water unit has DHW pipes coming in and out of it too. Does that mean BOTH units are producing hot water? Since they can't run independently both have been on, have we been creating double the hot water we need to?

This isn't bad. Once you know flow rate and temperatures (in and out, both sides, both HPs) you can figure out how much heat is being moved where.

If floor heat transfer is the problem, consider adding radiant walls (with plates) to supplement it.

I'd document everything well - photos, test results, buffer tank?, hot water heater?, air handler?, projected building load?, EAT/LAT, etc.

That is a PDF for a 50 hz unit, your model number shows different letters compared to the choices listed in the Key. (edit) I did find a 60 hz unit.

If they take down the ceiling to remove the batts, they could re-do the tubing with the plates.

That is a high temp W to W unit, Do you know what temp is being sent to the floors? How many water tanks do you have? Where do the pipes go from the HWG and the DHW?

CJ

You need to take a picture of your units and post it here. As Chris said a THW is a very rare and very expensive unit, we got to make sure we are getting the facts straight. The THW does not have a Desuperheater but can be ordered with a full time hot water generator, again very pricey option.

Having said that, you have 3 tons of radiant heating, and and 2 tons of forced air heating. The forced air might just heat the high ceiling.

Pipe on hangers has no conduction, thus only minimal heat transfer. You need as a a minimum aluminum heat transfer plates, other wise you will not get your floors up to comfortable temperatures.

Covering the pipes in spay foam is even more counterproductive.

The way the flora are right now, it will not heat your house with geo, even not with a high temp THW.

Totally agree about the pipes in spray foam being a bad idea, we nixed that fast and that let us know perhaps we were dealing with somebody who wasn't totally on top of what the issues are.

We had asked for gypcrete/warmboards and the gentleman told us that his drop-clips were better. We should have gone with our guts/what google said but he had so many years of installations and such good references. Now we're here. It seems the options get the radiant working are rip out everything: tile, backer board, subfloor and replace with warmboard or go in from below, remove downstairs ceilings and put on some Joist Trak panels to improve the efficiency (but not make it amazing).

I will attach photos but downstairs in our mechanical room we have a THW and a TES, then upstairs in the attic we have a TAH air handler, I swear!!

" That is a high temp W to W unit, Do you know what temp is being sent to the floors? How many water tanks do you have? Where do the pipes go from the HWG and the DHW? "

The buffer tank has been set to 137 which is the max the manufacturer recommends. We have been charting the radiant temps during the cold times. We had a 20 degree drop between what was sent and what was coming back so we have changed the speed on the circulator for that zone from "slow" to "medium". It is only 45 outside right now but this weekend it will snow and be in the teens so we are going to test it then to see if the drop is more in the 10 degree range. During cold times, the temperature being sent to the floors seems to be around 130-136 (the lower being when it's coldest outside). We have two water tanks: one is a regular hot water heater and then there's another hot water heater (40 gal) that's up on a pedestal being used as a storage tank (accumulator I think is the word?). We were quoted a 120 gallon stone lined tank but we did not get that.

I have not looked to see where the HWG/DHW pipes go. I can check on that tomorrow when I'm not in my pajamas and can crawl around in the mechanical room :-)

Water to Air Pump:



Water to Water Pump:



Air Handler in Attic:

Apologies, it seemed to limit me to three pictures in that post.

Water to Water unit LCD screen:




Circulator: (We have 3, one for each radiant zone). It has three options on the bottom: Lo, Med, Hi.

I am very surprised to see a high temp W-W Climatemaster. They are good machines, they are a Viessman design from Germany, built by climate master in license here in the US, it is only the second one I see since they are utterly expensive for their size.

Anyway, the efficiency of a w-w heat pump will depend on the temperature of the water it puts out. As a rule of thumb, you loose 15% for every 10 degrees hotter water. New buillt houses with a low heat loss usually run between 85-95 F supply temperature, where your set point is 130F. So you loose about 60% efficiency, if it works. Your is worth since it does not even work.
Indeed, top of the floor with aluminum plates, like the warm board works the best, I personally prefer the Rehau aluminum protruded plate system, but Warmboard would have been absolutely fine. Gypcrete would have been second best, but it has a higher thermal inertia. Under the floor works much worse since the what has to travel through the subfloor, requiring much higher supply temperature. OK in retrofits, not desirable in new builds. Absolutely worst is free clipped pipe. No conduction, just convection.
Sorry for the bad news, you need at least staple up with transfer plates with direct contact to the subfloors for conduction. And obviously top of the floor application is much better, but sometimes you have to play with the cards you got.

Posted By docjenser on 09 Jan 2016 12:49 AM
I am very surprised to see a high temp W-W Climatemaster. They are good machines, they are a Viessman design from Germany, built by climate master in license here in the US, it is only the second one I see since they are utterly expensive for their size.

Anyway, the efficiency of a w-w heat pump will depend on the temperature of the water it puts out. As a rule of thumb, you loose 15% for every 10 degrees hotter water. New buillt houses with a low heat loss usually run between 85-95 F supply temperature, where your set point is 130F. So you loose about 60% efficiency, if it works. Your is worth since it does not even work.
Indeed, top of the floor with aluminum plates, like the warm board works the best, I personally prefer the Rehau aluminum protruded plate system, but Warmboard would have been absolutely fine. Gypcrete would have been second best, but it has a higher thermal inertia. Under the floor works much worse since the what has to travel through the subfloor, requiring much higher supply temperature. OK in retrofits, not desirable in new builds. Absolutely worst is free clipped pipe. No conduction, just convection.
Sorry for the bad news, you need at least staple up with transfer plates with direct contact to the subfloors for conduction. And obviously top of the floor application is much better, but sometimes you have to play with the cards you got.

Thanks for the info and taking the time to respond. Had no idea our unit was different than what most people have. Most likely he did that because of the drop clips would be my guess? Seems like drop clips would be good for boiler applications with hot hot temps but not very good for geothermal where the hotter it gets the less efficient it is?

Do you think if we ripped out the ceilings, changed the tubing to be in contact with the upstairs floor and then surrounded them with some sort of thermal plate do you think that would:
A) Allow us to lower the temp of the water to make the unit more efficient
B) Actually heat the floor better?

My concern is that the 2 ton unit is actually undersized for what we're trying to do as well. Is there an easy way to tell that?

Posted By ChrisJ on 07 Jan 2016 11:39 AM
Where do the pipes go from the HWG and the DHW?

CJ

Ok, so....The HWG out is a red pex tube and it comes out of the HWG out outlet on the water --> Air unit does a bunch of 90 degree bends and then goes into the bottom of our domestic hot water heater. The DHW out is on the Water --> Water unit and it comes out the top, makes some turns and then T's into the red pex that comes out of the HWG outlet, if that makes any sense. I couldn't really get a picture of it as it goes all over the mechanical room.

Posted By MKer1 on 09 Jan 2016 10:41 AM

Posted By ChrisJ on 07 Jan 2016 11:39 AM
Where do the pipes go from the HWG and the DHW?

CJ

Ok, so....The HWG out is a red pex tube and it comes out of the HWG out outlet on the water --> Air unit does a bunch of 90 degree bends and then goes into the bottom of our domestic hot water heater. The DHW out is on the Water --> Water unit and it comes out the top, makes some turns and then T's into the red pex that comes out of the HWG outlet, if that makes any sense. I couldn't really get a picture of it as it goes all over the mechanical room.

Keep in mind that the THW does not have a conventional desuperheater, but a dedicated hot water generator for domestic hot water, which is a pricey but very elegant few thousand $$$ option. You can see on your screen that it controls the temp independently from your radiant water and should go directly into your hot water tank.

Only with regard to hydronic radiant floor emitter performance and directly from the instructions for our hydronic radiant floor heating software:

“Before you get too far with hydronic radiant floor system design, you should consider the upward heat effectiveness of the various floor emitters that you may be considering. The upward heat effectiveness percentage of a floor emitter may be calculated as (1 – ELR/2)/100, where ELR is the emitter efficiency loss ratio and is defined as the R-value above the tube divided by the R-value below the tube.

As a point of mental reference, the emitter efficiency loss ratio is zero if all of the R-value is below the tube and the floor emitter has a 100% upward heat effectiveness. The emitter efficiency loss ratio is 1 if 50% of the R-value is above and 50% is below the tube and the floor emitter has a 50% upward heat effectiveness. This means that only 50% of the heat supplied to the floor emitter actually moves upward into the living space. The other 50% percent of the heat is lost to the ground or space below the floor emitter. Once the emitter efficiency loss ratio becomes or exceeds 2, the floor emitter has a 0% upward heat effectiveness.

Slab-on-Grade, Thin-Slab, Above-Floor Tube & Plate and Below-Floor Tube & Plate floor emitters all having a 12 inch tube spacing provide 98.8%, 89.2%, 62.4% and 40.8% upward heat effectiveness respectively. These values are further degraded if any floor finishing material is used above these floor emitters. For example, using 3/4 inch hardwood flooring above these floor emitters results in 70.3%, 64.6%, 49.9% and 36.3% upward heat effectiveness respectively.

Even the location of where you place the tube in Slab-on-Grade will have an effect on the floor emitter upward heat effectiveness. Concrete is about 0.1 R-value per inch and EPS/XPS is about 5.0 R-value per inch. If you place the tube in the middle of a 5 inch thick Slab-on-Grade, the emitter efficiency loss ratio is (0.1)(2.5”)/[(0.1)(2.5”) +(5.0)(2”)] or 0.019 and (1 –0.019/2)/100 results in 98.8% upward heat effectiveness. If you instead place the tube on top of the 2” EPS, the emitter efficiency loss ratio is (0.1)(5”)/(5.0)(2”) or 0.05 and (1 –0.05/2)/100 results in a 97.5% upward heat effectiveness. This is a difference of 1.3% in floor emitter upward heat effectiveness.”

And:

“Once your hydronic radiant floor heating system is installed and operating, it may be used to assess the performance of BOTH your building design and your hydronic radiant emitter design. With regard to building design performance with an indoor temperature of 70 degrees F and outdoor temperature of 20F, we consider a hydronic radiant floor surface temperature of 70-74 degree F as excellent building design performance (i.e., a low-load, energy efficient building), a floor surface temperature of 75-80 degree F as average performance, and a floor surface temperature greater than 80 degree F as poor performance (i.e., a high-load, energy inefficient building). With regard to hydronic radiant emitter design performance, we consider a 9 degree F or less temperature difference between the hydronic radiant floor heat source supply temperature and the hydronic radiant floor surface temperature as excellent hydronic radiant emitter design performance, a 10-25 degree F temperature difference as average performance, and greater than a 25 degree F temperature difference as poor performance. One should always keep in mind that it can be very difficult and expensive to subsequently improve the performance of your building design and your hydronic radiant emitter design after they have been constructed.”

Borst Hydronic Radiant Floor Heating Design Software

Posted By MKer1 on 09 Jan 2016 10:35 AM

Posted By docjenser on 09 Jan 2016 12:49 AM
I am very surprised to see a high temp W-W Climatemaster. They are good machines, they are a Viessman design from Germany, built by climate master in license here in the US, it is only the second one I see since they are utterly expensive for their size.

Anyway, the efficiency of a w-w heat pump will depend on the temperature of the water it puts out. As a rule of thumb, you loose 15% for every 10 degrees hotter water. New buillt houses with a low heat loss usually run between 85-95 F supply temperature, where your set point is 130F. So you loose about 60% efficiency, if it works. Your is worth since it does not even work.
Indeed, top of the floor with aluminum plates, like the warm board works the best, I personally prefer the Rehau aluminum protruded plate system, but Warmboard would have been absolutely fine. Gypcrete would have been second best, but it has a higher thermal inertia. Under the floor works much worse since the what has to travel through the subfloor, requiring much higher supply temperature. OK in retrofits, not desirable in new builds. Absolutely worst is free clipped pipe. No conduction, just convection.
Sorry for the bad news, you need at least staple up with transfer plates with direct contact to the subfloors for conduction. And obviously top of the floor application is much better, but sometimes you have to play with the cards you got.

Thanks for the info and taking the time to respond. Had no idea our unit was different than what most people have. Most likely he did that because of the drop clips would be my guess? Seems like drop clips would be good for boiler applications with hot hot temps but not very good for geothermal where the hotter it gets the less efficient it is?

Do you think if we ripped out the ceilings, changed the tubing to be in contact with the upstairs floor and then surrounded them with some sort of thermal plate do you think that would:
A) Allow us to lower the temp of the water to make the unit more efficient
B) Actually heat the floor better?

My concern is that the 2 ton unit is actually undersized for what we're trying to do as well. Is there an easy way to tell that?

In other words on top is the best, Warmboard would have been fine, I prefer the Rehau Raupanel system for better performance, because it has a higher mass of aluminum in there, followed by slower responding gypcrete. Lesser good option are staple up with aluminum transfer plates. Least option are free hanging pipe without any conduction (contact) to the above floors. Yes to A) and yes to B) Tough to say if the 2 ton is undersized. Might be OK with some ceiling fans and a performing main floor.

The buffer tank has been set to 137 which is the max the manufacturer recommends. .. During cold times, the temperature being sent to the floors seems to be around 130

So your radiator (the floors) is delivering all of the heat that the W-W HP can produce (at this output temp). You are right to focus on your W-Air system first.

A troubleshooting guide is here. It is producing some warm air?

137 F load water is very inefficient. HEAT PUMP RUNS AT A COP between 2.0-2.3. All due to the floor requiring high temperatures.