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Superinsulated house with small GSHP

Last Post 11 Jun 2009 08:47 PM by engineer. 41 Replies.

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Palace Geothermal User is Offline

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Posts:1609

01 Apr 2009 11:23 AM
Posted By mkramer on 04/01/2009 10:57 AM Also, go to the white house website, search for desuperheater in H.R. 1, it does not exist in 455 pages of legislation! There is NO reqmt for a desuperheater, please stop putting out false information, you are hurting our industry. Sorry to bust your bubble but you are flat out wrong!! Go to this site and read it for your self http://www.energystar.gov/ia/partners/product_specs/eligibility/geo_heat_pump_elig.pdf You really should have better manners than to come as a new poster to this site, with no credentials and start blasting those who have established a good reputation here. Sounds like you are the one hurting the industry.

Dewayne Dean <br>www.PalaceGeothermal.com<br>Why settle for 90% when you can have 400%<br>We heat and cool with dirt!<br>visit- http://welserver.com/WEL0114/- to see my system

mkramer

New Member

Posts:8

01 Apr 2009 11:43 AM
Then explain to me how heat pumps without desupers have gotten the energy star rating? I'm looking at one right now, it has the energy star sticker, but no desuper. If I'm wrong on this then I'll admit it, and thanks for pointing that out to me. But as far as my manners, etc. you know nothing about me, just because you have been on a blog longer than me doesn't qualify you as an expert, you just have much more time on your hands than I do! Also, since i was correct on the desuper providing 80-100% of your hot water, why has no one admitted they were wrong on that? That's nice manners and professional. My gosh, if someone disagrees with you you start blasting them. Also, i haven't done any system where a desuper wasn't included, so I'm not hurting the industry.

egouin

Basic Member

Posts:126

01 Apr 2009 11:56 AM
Posted By mkramer on 04/01/2009 9:12 AM Egouin, what kind of heat pump did you put in, the very little hot water should not be true. When the unit is in cooling, you should get 100% of your hot water, when in heating, you should be getting about 80% of your hot water, something does not sound right to me here, give me some more info, by the way, did you do this yourself or hire someone in the industry? I had two 3-ton Climate Master Tranquility 27 units installed. Sqft is about 3800. Cubic feet of conditioned space is ~40,000. We get a lot of passive solar, in addition to having R45 SIP walls. On cold nights (near design temp) the units run and we wake up with a 50 gallon tank of ~90F water (up from well temp of 50F). We have not been through a cooling season yet. The fact is, unless it is quite cold outside, and the sun is not shining, the heat pumps run very little. With the shading provided by overhangs and deciduous trees, I don't expect our cooling load will be high either. It is a catch 22. Design a house will small heating and cooling requirements and a GSHP will not provide a lot of hot water (that is not to say they will not do so in a code-built house). At the end of the day, I'd choose solar with an on-demand backup rather than spend the extra money for the de-superheaters (which also need some sort of backup source). I am looking at adding an evacuated tube system from: http://www.sunmaxxsolar.com/. Ed

http://www.GouinGreen.com<br>Superinsulated SIP/Modular House (HERS = 30)<br>GSHP w/SCW, ERV, Passive Solar, Solar HW

egouin

Basic Member

Posts:126

01 Apr 2009 12:09 PM
Posted By Nick735 on 03/31/2009 8:21 PM Jeez i forgot to mention one of the most important things about the house; its location! It will be located in northeastern CT... since CT is so small i doubt you'll need the exact city ;-). Ed- Yea i was thinking that a desuperheater may not provide enough heat, especially if i am going with a small system. I am currently finishing a home right now that has solar heating via radiant. We havent fired it up yet, so i cant report how well it works, but I was considering going with a similar system for my dhw. Radiantec has a a package that consists of 2 solar panels, water tank, and all pre made manifolds for just under $4k. I dont want to go with solar & radiant for my personal home because unless you go with a slab, the cost and efficiency of the system goes out the window. What are the specs on your house? Sqft, Insulation, windows & doors, size of heating system etc? It would be great to bounce ideas off of each other. Nick Hi Nick, Feel free to contact me through www.GouinGreen.com. I love to talk about the project and share what I've learned. I also give tours to those who ask nicely. ;-) I am the only one who gets the email from that site. My house is R40 polyurethane SIPs with an extra layer of OSB and 1/2" foil faced polyiso board. Total R value is ~R47 with no thernal bridging. Roof is standard construction with about 7-8" of closed cell spray foam. All rafters are encased in foam, so no thermal bridging there either. Windows are vinly frame Alpen triple pane krypton filled. South facing is clear glass, all others are low-e. Slider is quadruple pane krypton. About 3,800 square feet / 40,000 cubic feet of conditioned space. Heating, cooling, and some DHW provided by 2 3-ton Climate Master Tranquility 27 units. Ground connection is via standing column well (we use our domestic water well). We have an Ultimate Air ERV for fresh air exchange. Finish hot water provided by a 96% efficient Noritz propane on-demand water heater. I expect to install a SunMaxx evacuated tube solar hot water system in the next few weeks/months - the complete setup costs under $3,500 and is quite efficient. Regards, Ed

http://www.GouinGreen.com<br>Superinsulated SIP/Modular House (HERS = 30)<br>GSHP w/SCW, ERV, Passive Solar, Solar HW

egouin

Basic Member

Posts:126

01 Apr 2009 12:25 PM
Posted By geo fan on 03/31/2009 8:41 PM hello neighbor I would push for a desuperheater , on the sole fact that it is required to be eligible for the 30% tax break . I would say a PV system and electric hot water as the main source of hot water would give the best bang for porky buck PV is CT is close to 75% paid for through state and fed credits Actually, evacuated tube solar hot water is likely the best bang for the buck. Heating 50 degree ground water with electricity is quite expensive. I can't speak for CT, but here in MA, the rebates and incentives are decent for PV, but it is still more expensive than buying green power directly from the grid. Desuperheaters effectively multiply the efficiency (x2 - x5 depending on model and conditions), but in a super-insulated house with passive solar, the units will not run enough to make it worth the added cost of the desuperheaters and storage tank. You can purchase a complete evacuated tube solar hot water system from SunMaxx for ~$3,500. Then you will need to add the cost of installation. Federal tax credits of up to $2,000 are available. In MA, there is a $1,000 tax credit. For me, this means SHW will cost $500 plus the cost of installation. The storage tank used with my desuperheaters cost more than that, and then there is still the cost of the desuperheaters! Please keep in mind, I believe desuperheaters are a wonderful technology. The should work quite well in a code-built home. However, in a super-insulated structure they add much less value. If manufacturers could find a way to use ground source heat pumps to heat hot water even when the house is not calling for heat or colling, then they'd really have something. Well, one manufactuer claims to have done this. Check out Hydro Delta. I ordered two of their Quadro Therm units and had to finally switch to Climate Master after waiting four months for the Hydro Delta units that never came. Ed

http://www.GouinGreen.com<br>Superinsulated SIP/Modular House (HERS = 30)<br>GSHP w/SCW, ERV, Passive Solar, Solar HW

Bergy

Basic Member

Posts:277

01 Apr 2009 01:07 PM
Posted By egouin on 04/01/2009 12:25 PM Posted By geo fan on 03/31/2009 8:41 PM Please keep in mind, I believe desuperheaters are a wonderful technology. The should work quite well in a code-built home. However, in a super-insulated structure they add much less value. If manufacturers could find a way to use ground source heat pumps to heat hot water even when the house is not calling for heat or colling, then they'd really have something. Well, one manufactuer claims to have done this. Check out Hydro Delta. I ordered two of their Quadro Therm units and had to finally switch to Climate Master after waiting four months for the Hydro Delta units that never came. Ed Ed; Hydro Delta has had problems with "On Demand" hot water generation. I've been told by several companies that on demand generation is not a good idea. Is it just that they don't do it? I don't know. I do,however, know we have replaced two Hydro Delta units less than ten years old. Bergy

egouin

Basic Member

Posts:126

01 Apr 2009 01:45 PM
I have no complaints about using Climate Master! It was wishful thinking that we could have had an "all-in-one" unit, but I am glad to have very reliable Climate Master equipment. My only regret is that I didn't start with SHW. Ed

http://www.GouinGreen.com<br>Superinsulated SIP/Modular House (HERS = 30)<br>GSHP w/SCW, ERV, Passive Solar, Solar HW

geo fan

Basic Member

Posts:408

01 Apr 2009 05:20 PM
Posted By egouin on 04/01/2009 12:25 PM Posted By geo fan on 03/31/2009 8:41 PM hello neighbor I would push for a desuperheater , on the sole fact that it is required to be eligible for the 30% tax break . I would say a PV system and electric hot water as the main source of hot water would give the best bang for porky buck PV is CT is close to 75% paid for through state and fed credits[/quote]Actually, evacuated tube solar hot water is likely the best bang for the buck. Heating 50 degree ground water with electricity is quite expensive. I can't speak for CT, but here in MA, the rebates and incentives are decent for PV, but it is still more expensive than buying green power directly from the grid. Desuperheaters effectively multiply the efficiency (x2 - x5 depending on model and conditions), but in a super-insulated house with passive solar, the units will not run enough to make it worth the added cost of the desuperheaters and storage tank. You can purchase a complete evacuated tube solar hot water system from SunMaxx for ~$3,500. Then you will need to add the cost of installation. Federal tax credits of up to $2,000 are available. In MA, there is a $1,000 tax credit. For me, this means SHW will cost $500 plus the cost of installation. The storage tank used with my desuperheaters cost more than that, and then there is still the cost of the desuperheaters! Please keep in mind, I believe desuperheaters are a wonderful technology. The should work quite well in a code-built home. However, in a super-insulated structure they add much less value. If manufacturers could find a way to use ground source heat pumps to heat hot water even when the house is not calling for heat or colling, then they'd really have something. Well, one manufactuer claims to have done this. Check out Hydro Delta. I ordered two of their Quadro Therm units and had to finally switch to Climate Master after waiting four months for the Hydro Delta units that never came. Ed I understand and agree , my recomendation was based on the 30% credit not being applied with out one ( which would pay for the desuperheater and then some ) this was/is my understanding after reading untill my eyes went crossed . but as allways I could be wrong. If so I agree 100% . As a side note Earthlinked has on demand with no problems , as do just about all DX companies . I dont quite understand why this is so excepted with DX and shunned with water source systems , but it seems to be the case . Also while solar has a long ROI it would offset the electric back up water . Might not be the best option , just a option

joe.ami

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01 Apr 2009 10:45 PM
Well, the link isn't working for me. I keep getting a blank page. But a desuperheater by definition is a system that recovers waste heat from a unit that is operating. So perhaps you know something I don't (most people do) but in the example I sited of a 1.5 ton, even if you dedicated 100% of the capacity to hot water it wouldn't rival a 10 gallon electric in January. Regarding the Hydrodelta comments, we'll see if Research products solves their problems before I sign on there. Geo on demand hot water...after servicing many Amana HTM's, I still have a problem with the notion of using the most expensive appliance in the house to do the job of the cheapest. Economy is not only about operating cost. Operating hours have a cost as well. Kramer- you take a harsh position on us but complain that we don't know you. Ummmm...okay glad you researched my 2 years and 800+ contributions before determining I have nothing better to do but misinform folks. Lighten up and maybe you can be more helpful than critical.... J

Joe Hardin www.amicontracting.com We Dig Comfort! www.doityourselfgeothermal.com Dig Your Own Comfort!

joe.ami

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01 Apr 2009 11:06 PM
Oops the pdf finally came through with the chart you directed me too. What I see is a suggestion that under ideal conditions you get <15% to <30% of the Btu's for the DSH. Curiously the chart is based on R-22 and derates for R-410. Now if you happen to employ a 2 stage unit you can derate a further 40% when in 1st stage. If entering water is lower you can derate it etc. By the same optimism I get 6 C.O.P. from my TTV49 and 30 EER. Designers deal in optimal circumstances, contractors only promise results that are sure to be delivered. Good Luck! Joe

Joe Hardin www.amicontracting.com We Dig Comfort! www.doityourselfgeothermal.com Dig Your Own Comfort!

joe.ami

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02 Apr 2009 08:17 AM
Regarding the question of how can a unit qualify for Energy Star rating and not have a DSH; A DSH isn't required by Energy Star (nobody said it was), but it is REQUIRED for a tax credit. J

Joe Hardin www.amicontracting.com We Dig Comfort! www.doityourselfgeothermal.com Dig Your Own Comfort!

tuffluckdriller User is Offline

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Posts:630

02 Apr 2009 03:48 PM
geo fan, EarthLinked's water heating setup, when not a desuperheater, is a year-round water heating unit for the domestic water, regardless if the home is heating or cooling. It will turn the heat pump on specifically to heat domestic water. We do this all the time.

Clark Timothy ([email protected])<br>Geothermal Heat Pumps: Heating and Cooling that's Dirt Cheap!<br>www.pinksgeothermal.com

geo fan

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Posts:408

02 Apr 2009 05:26 PM
A desuperheater / on demand I understand the difference while a may on occasion refer to on demand as an on demand desuperheater My question was more along the lines of why is on demand the default/recommended option for DX and not for water source I see the good and bad of either pretty clear , and the desuperheater has a clear advantage in cooling , a close to wash in heating , and on demand takes the cake in the shoulder . the only time I see one as better would be in cooling dominant areas but I dont get the " problem " with on demand and water source

joe.ami

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02 Apr 2009 09:38 PM
So far the problem with on demand water source is that it has been spear headed by failing companies. The problem with geo hot water in general is what I mentioned before. Given all sorts of savings, if a desuperheater can get the hot water production cost under a couple hundred bucks a year with a $250 electric water heater, do you really want to use a several thousand dollar appliance to shave $100 bucks a year off that? If a compressor replacement is $1,000 do you want to add hundreds of operating hours/year? Again I ask this as a guy who serviced the most efficient furnaces that also made hot water in the '80s. IMHO those customers spent thousands to save hundreds on heating water. j

Joe Hardin www.amicontracting.com We Dig Comfort! www.doityourselfgeothermal.com Dig Your Own Comfort!

geo fan

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02 Apr 2009 10:30 PM
Thank you While I dont think the math is that easy , I do agree with the thought In a retro where a hot water coil in a boiler was used the stack loss alone would likely justify the cost where electric was/is used the cost of the electric and water used ( if you pay 19cents and use a bunch of water ) the idea of close the quartering the operating cost year round could be justified Like you( I'm sure) running hours concerns me less then cycle count for compressor wear. and it would be tough for me to attatch a number to that . could it shave a year possibly , would it shave 5 in my opinion not a chance especially when compared to air to air which operate with much higher head which is arguably is just as bad . I just think there is a place for them , is that place Florida not really , is it a super insulated home where the hot water load rivals the home possibly . just a thought

joe.ami

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03 Apr 2009 06:31 AM
Good point, our users here pay as little as .075/KWH. At .19, I could easily justify the extra maintenance on and expensive appliance (including the old Amana HTM's which by the way heated glycol that was circulated through a fan coil or a boiler mate). I do not remember which DX system you install, but lower head pressures are not true in water source systems as they are all (unfortunately) going R-410. Water source companies have made water to water heat pumps for years which do great at domestic hot water but not with the same C.O.P.'s, so it's not that the technology isn't there. DX doesn't achieve the same C.O.P's heating water as it does air but because it's a modular system, we get to use it's highest numbers to qualify it for Energy Star. So at this time it is a better bet in my mind for potable hot water. More reputable companies than hydro are moving into the on demand market. Econar was already moving that way, and since RP bought Hydro as well they have a nice combination of a reliable manufacturer to use the Hydro patents with their engineering and great reputation, good things hopefully will come. j

Joe Hardin www.amicontracting.com We Dig Comfort! www.doityourselfgeothermal.com Dig Your Own Comfort!

Glen Wright User is Offline

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08 Jun 2009 10:43 PM
Whomever you use make sure of the company’s tech support. I would not recommend TETCO or any Chiller solutions products as I have been asking for tech support for nearly a year and been ignored.

jonr

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Posts:5341

09 Jun 2009 02:30 PM
KWH saved are KWH saved. So you don't want to heat water with a standard electric water heater any more than you want to heat your house with electric heat. If putting hours on your HP isn't worth it for one, then it isn't worth it for the other. IMO, look at the economics of a combined unit (such as the Waterfurnace 3D) or a separate water to water unit for radiant heat and geothermal on demand DHW. Here is a well proven example of the latter: http://www.ourcoolhouse.com/monitor/monitor.htm

joe.ami

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09 Jun 2009 07:31 PM
The Pros in the industry are: A) disinclined (by and large) to use on demand hot water. B) Okay with storage tanks. C) not offended by stand by loss (vs operating hours). Posted By jonr on 06/09/2009 2:30 PM KWH saved are KWH saved. So you don't want to heat water with a standard electric water heater any more than you want to heat your house with electric heat. -Ummm depends on your choices......I could also burn hndreds of gallons of propane to save a KW. Not a good trade in my world. If putting hours on your HP isn't worth it for one, then it isn't worth it for the other. -I don't know what this statement refers too, but if it is DX vs water source then jon is correct, I feel it is a bad idea in both applications. Operating hours have a price tag just as surely as miles on a car. While one mile may only cost you 25 cents worth of gas, the maintenance and insurance and purchase price and...... on a new car could easily cost more, than a '72 Impala that guzzles gas, per mile. IOWs economy is not limited to MPG (mechanics understand this while gadget guys might not), but a salesman might not suggest that to you on a car lot. JMHO joe

Joe Hardin www.amicontracting.com We Dig Comfort! www.doityourselfgeothermal.com Dig Your Own Comfort!

geo fan

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09 Jun 2009 07:58 PM
Every situation is different broad statements dont work a comercial job that goes through a couple thousand gallons a day and pays 20plus cents per kwh and a single home owner using less then a hundred gallons a day and paying 8 cents cant be compared ( as extreme examples ) I do see a clear benifit in warm climates towards a desuperheater , and the further north you go the more that line gets blured and thats before economics gets involved, but lets say its a wash or close to it , ie the additional cost and "miles " equaled the money saved ( for that specific aspect of the equipment , when compared to a desuperheater ) then whats the harm , if it costs more, well I would want to see the numbers on that , and of course understand that specific situation