Inefficient home or inefficient GSHP?

[Mikesolar]

Originally Posted by mechanic

It's 2x6 with typar wrap on the outside then vinyl siding. I ordered one of those flir iPhone cameras for our business, at that price it should be a pretty useful tool. I'll maybe price out that blower test, were 65km out of the city so mileage is a killer... I blocked out stage 2 for now. Hp manual says that limits it to 67%.

I think that keeping the HP on stage one may make its output to be better matched to the loop field. It is worth a try. As there is no buffer tank, it will allow for longer run times, which is good.

[mechanic]

There is no insulation under the floor, there is just 6" of crushed rock, then a radon barrier, then treated 2x4's with interlocking plywood. It feels warm on the feet but I suppose it could be sucking some heat. Another thing I just realized is the ground loop runs across the basement about 2' under the crushed rock...

[Mikesolar]

Sir, you have some work to do. Luckily, the floor is not so hard but having the tubing so close and uninsulated is not good. eventually, as the temps in the loops go down and it takes more heat out of the soil, it could effect your footings.

[AC_Hacker]

Looks like this whole thread is a testament to the need to design carefully before building.

-AC

[mechanic]

Ya, at the time we just kinda followed what the different contractors told us we should do. Do most people insulate under the basement floor? Any basement floors I've seen around here are usually just concrete on top of a gravel layer...

[mechanic]

Stage one is keeping up fine right now but it cuts in and out a lot. I adjusted the min runtime to ten minutes and the min time between cycles to 10 as well, we'll see how that works

[Mikesolar]

Originally Posted by mechanic

Stage one is keeping up fine right now but it cuts in and out a lot. I adjusted the min runtime to ten minutes and the min time between cycles to 10 as well, we'll see how that works

3-4 minutes for an off cycle is fine. 10 minutes as minimum run time MIGHT be an issue but lets see. As long at it doesn't start going out on a high limit switch, it may be better. I don't know of any loops that go out under the floor, usually they go out the wall or occasionally above grade like Randens then down but I am sure there are some. I wouldn't do it.

I must be in a little (but growing) bubble of people who want better than code. All I put in basements is floor heating and this always gets at least 2" of foam, 3-4 if possible.

I suggest you start planning for what you can do and the basement is part one. One thing you can do in the summer, if you can, is to lay foam flat 2 ft under grade and out 4-6 ft from the house wall (all around). This will bring the heated thermocline up and keep the entire area under the house from getting as cold over the winter. It is labourious but doable.

Then....get onto the walls. Extend the extra foam right down as low as you can below grade. Big benefit.

Pics of the house would be nice. hint hint.

[sunspot]

Originally Posted by Mikesolar

...One thing you can do in the summer, if you can, is to lay foam flat 2 ft under grade and out 4-6 ft from the house wall (all around). This will bring the heated thermocline up and keep the entire area under the house from getting as cold over the winter. It is labourious but doable.

Then....get onto the walls. Extend the extra foam right down as low as you can below grade. Big benefit.

I'm interested in this as well. If anyone has gone down this path and has some data to share I'm very interested.

[SDMCF]

Originally Posted by Mikesolar

One thing you can do in the summer, if you can, is to lay foam flat 2 ft under grade and out 4-6 ft from the house wall (all around). This will bring the heated thermocline up and keep the entire area under the house from getting as cold over the winter. It is labourious but doable.

Then....get onto the walls. Extend the extra foam right down as low as you can below grade. Big benefit.

Mike, am I right in thinking that advice only applies to structures with a slab rather than a crawl space?

[Mikesolar]

Originally Posted by SDMCF

Mike, am I right in thinking that advice only applies to structures with a slab rather than a crawl space?

Nope, it is useful anywhere. It is a Swedish/Finish technique that I have used a few times and seems to help with anything that needs a footing protected. As long as you do proper insulation on the exterior of the foundation wall, it will protect the crawlspace better than exterior insulation alone.