Why are GHP so expensive? - Page 2

AC_Hacker · 03-06-11, 06:52 PM

Quote:

Originally Posted by okpiddler

Zoned, tubing in post tension slab. 2 600' loops of HDPE buried in a 6' deep by 3' wide and 300' long. Bury it before building the house. Zig zag across the lot.

Hey, this is all music to my ears!

And okpiddler is completely right on about putting in the GSHP ground work before building a house.

The problem gets a bit tougher when you're in the city, because so many city lots are 50' x 100'.

But if you do the earth work first, it sure would be a lot easier.

Quote:

Originally Posted by okpiddler

We need to get together and start a factory with smaller units for folks that have smaller homes and try to save energy.

Fantastic idea...

Got more thinking along this line?

Regards,

-AC_Hacker

Geo NR Gee · 03-07-11, 09:56 AM

Last night I spent 2 hours typing only hit a page back somehow and loose all of it. This morning after spending 2 hours again typing, it said lost token....... I will try to respond later.

Geo NR Gee · 03-07-11, 10:44 AM

$5000 is probably a great price compared to other systems that are over $15,000 and more. Thats what a lot of folks need. But for some, its still a lot of money.

We had an energy audit (2010) on our 1710 sq. ft. home built in 1998. It was built under the "Good Cents" program (http://www2.cstx.gov/pc/green/docs/gcs_goodcents.pdf). The audit showed a few areas where we needed to insulate or seal. Two that are found in most of the homes the auditor inspected are the top of the moldings on the front and garage doors. Our house was no different.

Other than sealing some ductwork in the crawl space and fabricating sheetrock boxes for the recessed lighting cans in the attic and adding new low E windows (which we can't afford), the house is pretty well insulated.

Why can't a ASHP be used as a starting point. I have found many 2, 2.5, and 3 ton units for around $200. Seems that one could replace the condensor with a closed ground loop and start moving heat. Maybe I am missing something?

My home is already set up for an A/C coil in the heating system (no coil, just the empty box). We have a 96% efficent gas furnace already. If I use natural gas for the back up and the GSHP for the main, we would be set.

Our home is built on a small lot. I could probably get only a 300ft. ditch for slinky pipe on the property. That would have to be taken into consideration and vertical might be more likely here. There is no access to the back yard for a well digging machine, so manual and homemade drilling will be most likely the way my three teenage boys will have to do it. hehe

gasstingy · 03-07-11, 12:46 PM

Last year I asked a GSHP contractor for a guesstimate on my house. Fairly well insulated 1520sf heated area, all ducts (3 ton unit) run through the attic. He told me at that time that since I had enough property to do a horizontal ground loop, and if he could reuse my existing ductwork (he said he probably could), it would cost around $13,000. For now, though, that's still more than I have available for a new unit.

AC_Hacker · 03-07-11, 01:37 PM

Quote:

Originally Posted by gasstingy

...it would cost around $13,000...

You can do a lot of digging and planting plastic for $13,000. A GSHP that would work with your air-handler unit can be had for surprisingly little... just search around on ebay.

But keep in mind that a radiant floor setup will give you a better COP, which will work in your favor as time goes on... and once the ground loop is in, you can use it for forced air or radiant floor.

Hydronic radiators would be in the same league as forced air, as far as COP goes, though... not much benefit in your case.

-AC_Hacker

AC_Hacker · 03-07-11, 01:41 PM

Quote:

Originally Posted by braebyrn

Why can't a ASHP be used as a starting point. I have found many 2, 2.5, and 3 ton units for around $200. Seems that one could replace the condensor with a closed ground loop and start moving heat. Maybe I am missing something?

My home is already set up for an A/C coil in the heating system (no coil, just the empty box). We have a 96% efficent gas furnace already.

I think that a ASHP/GSHP hybrid would really work well for you, being as how you are in the Pacific North West weather zone.

ASHP for the days that are above 32 and GSHP for the days below.

Get your teens to use a mini backhoe to dig that 300 foot trench. With a hybrid system, 300 feet would work out well.

Your brother could probably work out the controller and valve-switching.

-AC_Hacker

Geo NR Gee · 03-07-11, 01:52 PM

Quote:

Originally Posted by gasstingy

..... it would cost around $13,000. For now, though, that's still more than I have available for a new unit.

I hear ya.

Geo NR Gee · 03-07-11, 02:01 PM

Quote:

Originally Posted by AC_Hacker

ASHP for the days that are above 32 and GSHP for the days below.
-AC_Hacker

What I meant was to bring the heat pump indoors only. But after thinking about what you said, that makes a lot of sense now.

03-07-11, 10:44 AM	#13
Geo NR Gee Journeyman EcoRenovator Join Date: Jan 2011 Location: Seattle Posts: 326 Thanks: 109 Thanked 23 Times in 18 Posts	$5000 is probably a great price compared to other systems that are over $15,000 and more. Thats what a lot of folks need. But for some, its still a lot of money. We had an energy audit (2010) on our 1710 sq. ft. home built in 1998. It was built under the "Good Cents" program (http://www2.cstx.gov/pc/green/docs/gcs_goodcents.pdf). The audit showed a few areas where we needed to insulate or seal. Two that are found in most of the homes the auditor inspected are the top of the moldings on the front and garage doors. Our house was no different. Other than sealing some ductwork in the crawl space and fabricating sheetrock boxes for the recessed lighting cans in the attic and adding new low E windows (which we can't afford), the house is pretty well insulated. Why can't a ASHP be used as a starting point. I have found many 2, 2.5, and 3 ton units for around $200. Seems that one could replace the condensor with a closed ground loop and start moving heat. Maybe I am missing something? My home is already set up for an A/C coil in the heating system (no coil, just the empty box). We have a 96% efficent gas furnace already. If I use natural gas for the back up and the GSHP for the main, we would be set. Our home is built on a small lot. I could probably get only a 300ft. ditch for slinky pipe on the property. That would have to be taken into consideration and vertical might be more likely here. There is no access to the back yard for a well digging machine, so manual and homemade drilling will be most likely the way my three teenage boys will have to do it. hehe Last edited by Geo NR Gee; 03-07-11 at 10:54 AM..

03-07-11, 09:56 AM	#12
Geo NR Gee Journeyman EcoRenovator Join Date: Jan 2011 Location: Seattle Posts: 326 Thanks: 109 Thanked 23 Times in 18 Posts	Last night I spent 2 hours typing only hit a page back somehow and loose all of it. This morning after spending 2 hours again typing, it said lost token....... I will try to respond later.

03-07-11, 12:46 PM	#14
gasstingy Journeyman EcoRenovator Join Date: Feb 2010 Location: Arab, AL Posts: 491 Thanks: 109 Thanked 49 Times in 43 Posts	Last year I asked a GSHP contractor for a guesstimate on my house. Fairly well insulated 1520sf heated area, all ducts (3 ton unit) run through the attic. He told me at that time that since I had enough property to do a horizontal ground loop, and if he could reuse my existing ductwork (he said he probably could), it would cost around $13,000. For now, though, that's still more than I have available for a new unit.