GSHP or ASHP 27 seer minsplits?

gtojohn · 09-28-14, 08:38 AM

Im in the design phase of a lake house. Currently I have 1 acre thats been relatively untouched and "unimproved" by people. Meaning no well or water service. Power can be made available, there's a pole at the street. This is just a weekend getaway until we retire or decide we want to move there permanently. I have around 3kw of solar I haven't been able to install on my current home. The power coop will credit me .0345 a kw I generate, and charge about .10 per kw I use. The plan is to make power all week and use the hvac only when we're there to net $0 electric bills. Construction will be as efficient and self sustaining as I can on shoestring budget. My current plan has about 1000sqft, mostly open floor plan with 1 real bedroom and 1 loft space. I think I can get away with 2 a/c zones.
Currently I've found a 9kbtu Gree 27 seer minisplit complete for about $1000 delivered. I would need 2. This is a little more efficient than I could get a 2 zone system for at the same price range. The added benefit would be the redundancy of 2 seperate systems.

I guess the main question is- is there any point in looking further into GSHP for the time, trouble and payback?

I hope to begin construction in the late fall.

AC_Hacker · 09-28-14, 10:42 AM

Quote:

Originally Posted by gtojohn

Im in the design phase of a lake house ... is there any point in looking further into GSHP for the time, trouble and payback?

I am probably the biggest supporter of GSHP on the forum.

Knowing nothing about you, or your gumption, or your set of deep skills at creative fabrication, or any sense of idealism that you may have regarding energy depletion, global warming, or your budget...

I would advise you to do the Cree ASHP thing, because it is the path of least resistance.

I would however, advise you to do all the research you can about insulation, and passive cooling, etc. before you decide on your heating and cooling requirements.

-AC

pinballlooking · 09-28-14, 04:37 PM

For DIY GSHP install check out AC_Hacker post.
http://ecorenovator.org/forum/geothe...manifesto.html

Check out my post
http://ecorenovator.org/forum/geothe...t-install.html

I have installed three of the Gree Terra series 27 seer. I ran one for over a year and liked it so much I bought two more.

These guys add the line set and the JMF wiring in the price.
9,000 BTU, 208/230 Volt Terra Ductless Mini Split - ComfortUp

we really like them I also have LG mini splits but the Gree adjust 1 deg at a time. I have found that to get a comfortable temp there is usually about 3 deg. We can find a comfortable don’t mess with temp much quicker on the Gree units. Those units really sip power when they are in cooling mode.
I was thing about GSHP but I am very glad I went with these instead. After a few years I can swap out the MS and still come out ahead.

gtojohn · 09-28-14, 10:18 PM

The Terra is the one I was looking at. 9kbtu for 333watts by my calculations. I think it will be hard for me to improve on. I've had good luck with other Gree installs and there is a local dealer, depending on their price it can make warranties and support much faster. I had electricians 240 a 120v unit last winter. Because it was bought from the internet it took a good month to receive a new control board from china. There is something to be said about least resistance. It will allow me to focus on several other parts of this build. Insulation and passive design will be a big part of my project. One benefit of building a smaller house is its cheaper to make efficient.

AC_Hacker · 09-29-14, 10:50 AM

Quote:

Originally Posted by gtojohn

The Terra is the one I was looking at. 9kbtu for 333watts by my calculations. I think it will be hard for me to improve on...

I have noticed that concerning heating a house or cooling a house (even a house that hasn't been built yet!), virtually everybody begins by thinking of the best, most efficient, most economical heating or cooling system. It's basic human nature, it has served us well for as far back in the chain of evolution as you are willing to go.

But the approach of siting and designing a house so that it takes advantage of natural advantages of sun, shade, wind factors (both positive and negative), and also conserves as much as is possible of the the warmth or coolness that we require for comfort, usually ends up being an unattended detail.

As I am finding, retrofitting my own house, a house that was built in 1892, that was never designed to take advantage of environmental factors, is difficult and expensive. While I am steadily reducing the energy required to run my house, it will never come close to being as comfortable and as economical to maintain as would be a house that was designed from the beginning, to use the forces of nature to create and maintain comfort, rather than to rely on manufactured energy to create comfort, in spite of the forces of nature.

-AC

SDMCF · 09-29-14, 12:01 PM

Quote:

Originally Posted by AC_Hacker

As I am finding, retrofitting my own house, a house that was built in 1892, that was never designed to take advantage of environmental factors ...

I would be surprised if you house was really not designed to take advantage of environmental factors. My house is the same age and - to the limits of the time - it certainly has features that were designed to take advantage of the environment. For example, there are 4 separate spaces designed to be cold for the storage of food, all of which are totally passive and take advantage of the environment for that. Or the way the house is aligned to face the rising & setting sun in spring and Autumn, when it can contribute to heating, rather than in winter when the sun is weak and there are few hours of daylight. Or the way it is built near the top of a slope rather than at the bottom, so that drainage of waste water is more easily managed. Or the way it is built of materials easily available in the local area.

It is true that the the house will never be as well insulated or sealed as a modern house, but that doesn't mean the original builders ignored all environmental factors. In my view they did the best they could, and I am constantly impressed with what they achieved.

Or perhaps I am an eternal optimist, always looking on the bright side

AC_Hacker · 09-30-14, 09:35 PM

Quote:

Originally Posted by SDMCF

...Or perhaps I am an eternal optimist, always looking on the bright side

Unfortunately, entropy never looks on the bright side.

-AC

gtojohn · 10-01-14, 09:27 AM

People were tougher back then, they had more important things to worry about like food and water supplies, not freezing to death, being eaten by bears etc. Our famliy's german built, pre-civil war farm house still stands, relatively comfortable without a/c despite our miserable weather. Very cool temperature underground root cellar. Underground cisterns and stock ponds built with actual horse power, probably a couple of mules.

My previous power calculation was wrong, I did eer using the seer spec. EER is 14.5, uses 620 watts for 9kbtu.

09-28-14, 08:38 AM	#1
gtojohn Journeyman EcoRenovator Join Date: Jul 2014 Location: Austin, TX Posts: 314 Thanks: 39 Thanked 50 Times in 45 Posts	GSHP or ASHP 27 seer minsplits? Im in the design phase of a lake house. Currently I have 1 acre thats been relatively untouched and "unimproved" by people. Meaning no well or water service. Power can be made available, there's a pole at the street. This is just a weekend getaway until we retire or decide we want to move there permanently. I have around 3kw of solar I haven't been able to install on my current home. The power coop will credit me .0345 a kw I generate, and charge about .10 per kw I use. The plan is to make power all week and use the hvac only when we're there to net $0 electric bills. Construction will be as efficient and self sustaining as I can on shoestring budget. My current plan has about 1000sqft, mostly open floor plan with 1 real bedroom and 1 loft space. I think I can get away with 2 a/c zones. Currently I've found a 9kbtu Gree 27 seer minisplit complete for about $1000 delivered. I would need 2. This is a little more efficient than I could get a 2 zone system for at the same price range. The added benefit would be the redundancy of 2 seperate systems. I guess the main question is- is there any point in looking further into GSHP for the time, trouble and payback? I hope to begin construction in the late fall.

09-28-14, 04:37 PM	#3
pinballlooking Super Moderator Join Date: Jun 2013 Location: SC Posts: 2,923 Thanks: 172 Thanked 564 Times in 463 Posts	For DIY GSHP install check out AC_Hacker post. http://ecorenovator.org/forum/geothe...manifesto.html Check out my post http://ecorenovator.org/forum/geothe...t-install.html I have installed three of the Gree Terra series 27 seer. I ran one for over a year and liked it so much I bought two more. These guys add the line set and the JMF wiring in the price. 9,000 BTU, 208/230 Volt Terra Ductless Mini Split - ComfortUp we really like them I also have LG mini splits but the Gree adjust 1 deg at a time. I have found that to get a comfortable temp there is usually about 3 deg. We can find a comfortable don’t mess with temp much quicker on the Gree units. Those units really sip power when they are in cooling mode. I was thing about GSHP but I am very glad I went with these instead. After a few years I can swap out the MS and still come out ahead. Last edited by pinballlooking; 09-28-14 at 04:46 PM..

09-28-14, 10:18 PM	#4
gtojohn Journeyman EcoRenovator Join Date: Jul 2014 Location: Austin, TX Posts: 314 Thanks: 39 Thanked 50 Times in 45 Posts	The Terra is the one I was looking at. 9kbtu for 333watts by my calculations. I think it will be hard for me to improve on. I've had good luck with other Gree installs and there is a local dealer, depending on their price it can make warranties and support much faster. I had electricians 240 a 120v unit last winter. Because it was bought from the internet it took a good month to receive a new control board from china. There is something to be said about least resistance. It will allow me to focus on several other parts of this build. Insulation and passive design will be a big part of my project. One benefit of building a smaller house is its cheaper to make efficient.

10-01-14, 09:27 AM	#8
gtojohn Journeyman EcoRenovator Join Date: Jul 2014 Location: Austin, TX Posts: 314 Thanks: 39 Thanked 50 Times in 45 Posts	People were tougher back then, they had more important things to worry about like food and water supplies, not freezing to death, being eaten by bears etc. Our famliy's german built, pre-civil war farm house still stands, relatively comfortable without a/c despite our miserable weather. Very cool temperature underground root cellar. Underground cisterns and stock ponds built with actual horse power, probably a couple of mules. My previous power calculation was wrong, I did eer using the seer spec. EER is 14.5, uses 620 watts for 9kbtu.