Ran across this

Fordguy64 · 06-26-16, 09:05 PM

http://aceee.org/files/proceedings/2...pers/1-483.pdf

I found this to be a pretty interesting read. I ran across it looking into thermal batteries.

DEnd · 06-29-16, 04:07 AM

Yep they have those.

Daikin has the Altherma system which is air source, but not available in North America.

Basically what is available in North America are Ground Source Heat Pumps with Desuperheaters for hot water. Those are expensive to buy, expensive to install, and can be difficult to maintain.

stevehull · 06-29-16, 06:18 AM

DEnd,

I disagree that geothermal heat pumps are "expensive, problematic and difficult to maintain".

In 1992, I put in two WaterFurnace open loop geothermal heat pumps in my home. The savings literally put two kids through college . . . . and free hot water in summer (and very inexpensive in winter) was a huge issue with three kids.

Difficult to maintain? I think my major investment were good air filters. These heat pumps are still running flawlessly almost 25 years later.

The install is important - find a dealer who knows what they are doing.

The majority of people that put these GTHPs in are very pleased. There are always problems, but quality, even if initially costly, always gives a long term investment.

Today, I would use Ingram's for purchasing GT heat pumps. The technology is almost cookie cutter and Ingram's has simply superb prices and equipment.

Geothermal Heat Pump Systems | Buy Goodman Heat Pump | Geothermal Heat Pumps | Goodman Air Conditioner

Steve

oh - just remembered I had to top off the R22 in one of these a few years back.

DEnd · 06-29-16, 01:52 PM

Steve, I completely agree that a Ground Source Heat Pump can be just as reliable or even more reliable than an air source system. In fact it should be, unfortunately that isn't always the case. Even good installs still don't address the first cost issue. Inverter driven air source heat pumps can match or beat the Coefficient Of Performance of a GSHP on the majority of heating and cooling hours. For the majority of the country the additional first cost of a GSHP isn't justified by the savings you get on the hours the GSHP beats the COP of an inverter driven air source heat pump.

With my house I didn't have a clear enough picture of savings to justify a GSHP over a conventional system. Had I been able to do better energy modeling than the guesstimation I did that may have changed, but I didn't know enough then to demand it to be done.

mejunkhound · 07-11-16, 06:46 AM

For a DIY scrounger type install , there is no reason to use a reversible system.

Scroll compressors are only a few hundred $$ on ebay or CL.
Each system is more efficient if one does not try to size evap and condenser to be interchangeable, plus for non-reversible, an oversized condenser can also be used as a receiver and COP increased for HP operation.

Here are my economics:
HP water heater (GE) 100% paid for by power company, so why not, zero cost for that part.

GSHP is heat pump only, evap is tube in tube made from surplus pvc pipe and cleaned old Cu water pipe, oversized scrap price surplus condenser, new 4T scroll compressor was $400, < $100 for other parts.

Do have an air-source HP/AC that installed 15 years ago before I was educated enough to have not known better. Air-Air HP used when air temp > 43F, then switch (automatically) to GSHP.
Air handler has 2 separate condensors, one for air-air, the other for the gshp.

Of course, if NOT scrounge DIY, when reversing valves do make sense just from economics of first cost.

But since this is a primarily DIY scrounger site, thought I throw in my 2 cents on reversible systems.

jeff5may · 07-11-16, 08:06 AM

The fact of the matter is that the reversing-cycle, inverter driven, variable capacity air source units are much more complex than a typical single-speed ground source (or "outdated" air source) unit. Guess which one usually breaks down first? Solid-state controls are much less rugged than mechanical contactors. Save some money on those inflated SEER numbers and buy some insulation with it. Then come back in 20 years with a review.

06-26-16, 09:05 PM	#1
Fordguy64 Journeyman EcoRenovator Join Date: Oct 2011 Location: Cincinnati ohio Posts: 338 Thanks: 40 Thanked 35 Times in 31 Posts	Ran across this http://aceee.org/files/proceedings/2...pers/1-483.pdf I found this to be a pretty interesting read. I ran across it looking into thermal batteries.

06-29-16, 06:18 AM	#3
stevehull Steve Hull Join Date: Dec 2012 Location: hilly, tree covered Arcadia, OK USA Posts: 826 Thanks: 241 Thanked 165 Times in 123 Posts	DEnd, I disagree that geothermal heat pumps are "expensive, problematic and difficult to maintain". In 1992, I put in two WaterFurnace open loop geothermal heat pumps in my home. The savings literally put two kids through college . . . . and free hot water in summer (and very inexpensive in winter) was a huge issue with three kids. Difficult to maintain? I think my major investment were good air filters. These heat pumps are still running flawlessly almost 25 years later. The install is important - find a dealer who knows what they are doing. The majority of people that put these GTHPs in are very pleased. There are always problems, but quality, even if initially costly, always gives a long term investment. Today, I would use Ingram's for purchasing GT heat pumps. The technology is almost cookie cutter and Ingram's has simply superb prices and equipment. Geothermal Heat Pump Systems \| Buy Goodman Heat Pump \| Geothermal Heat Pumps \| Goodman Air Conditioner Steve oh - just remembered I had to top off the R22 in one of these a few years back. __________________ consulting on geothermal heating/cooling & rational energy use since 1990 Last edited by stevehull; 06-29-16 at 06:32 AM.. Reason: clarity and honesty

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06-29-16, 04:07 AM	#2
DEnd Apprentice EcoRenovator Join Date: Nov 2011 Location: NC Posts: 117 Thanks: 6 Thanked 27 Times in 25 Posts	Yep they have those. Daikin has the Altherma system which is air source, but not available in North America. Basically what is available in North America are Ground Source Heat Pumps with Desuperheaters for hot water. Those are expensive to buy, expensive to install, and can be difficult to maintain.

06-29-16, 01:52 PM	#4
DEnd Apprentice EcoRenovator Join Date: Nov 2011 Location: NC Posts: 117 Thanks: 6 Thanked 27 Times in 25 Posts	Steve, I completely agree that a Ground Source Heat Pump can be just as reliable or even more reliable than an air source system. In fact it should be, unfortunately that isn't always the case. Even good installs still don't address the first cost issue. Inverter driven air source heat pumps can match or beat the Coefficient Of Performance of a GSHP on the majority of heating and cooling hours. For the majority of the country the additional first cost of a GSHP isn't justified by the savings you get on the hours the GSHP beats the COP of an inverter driven air source heat pump. With my house I didn't have a clear enough picture of savings to justify a GSHP over a conventional system. Had I been able to do better energy modeling than the guesstimation I did that may have changed, but I didn't know enough then to demand it to be done.

07-11-16, 06:46 AM	#5
mejunkhound Apprentice EcoRenovator Join Date: Apr 2011 Location: PNW Posts: 197 Thanks: 0 Thanked 47 Times in 31 Posts	For a DIY scrounger type install , there is no reason to use a reversible system. Scroll compressors are only a few hundred $$ on ebay or CL. Each system is more efficient if one does not try to size evap and condenser to be interchangeable, plus for non-reversible, an oversized condenser can also be used as a receiver and COP increased for HP operation. Here are my economics: HP water heater (GE) 100% paid for by power company, so why not, zero cost for that part. GSHP is heat pump only, evap is tube in tube made from surplus pvc pipe and cleaned old Cu water pipe, oversized scrap price surplus condenser, new 4T scroll compressor was $400, < $100 for other parts. Do have an air-source HP/AC that installed 15 years ago before I was educated enough to have not known better. Air-Air HP used when air temp > 43F, then switch (automatically) to GSHP. Air handler has 2 separate condensors, one for air-air, the other for the gshp. Of course, if NOT scrounge DIY, when reversing valves do make sense just from economics of first cost. But since this is a primarily DIY scrounger site, thought I throw in my 2 cents on reversible systems.

07-11-16, 08:06 AM	#6
jeff5may Supreme EcoRenovator Join Date: Jan 2010 Location: elizabethtown, ky, USA Posts: 2,428 Thanks: 431 Thanked 619 Times in 517 Posts	The fact of the matter is that the reversing-cycle, inverter driven, variable capacity air source units are much more complex than a typical single-speed ground source (or "outdated" air source) unit. Guess which one usually breaks down first? Solid-state controls are much less rugged than mechanical contactors. Save some money on those inflated SEER numbers and buy some insulation with it. Then come back in 20 years with a review.