Yes I intend to have fresh air supplies in bedrooms but they are so big, the ducts are sized down to 4 inch.

I do understand that I could penetrate the wall and hang one of those gawd awfully looking units hanging on the side of the house. It's just not something we want. My wife would not be happy about that.

So back to Pheonix and cliamatemaster.....Any other choices that may make sense? A little Munchkin boiler and climatemaster with a dual coil storage tank?

The whole notion of burning propane even as a backup just doesn't feel right- methinks you're over-thinking/over-designing the mechanicals here. But if you're going to burn propane, with your radiation and heat loads a Polaris or Vertex water heater (with heat exchanger) are probably a more appropriate solution.

While I am with you, Roundeye, on the not wanting a mini-split head sticking out of the wall, I agree with Dana1 about designing a system without propane. Couldn't the water to water heat pump do the radiant and DHW, then in summer change the radiant buffer tank water to chilled water for one or two air coils a/c?

I still am having trouble understanding the ground loop lay-out. 2000 ft of pipe under your sq ftage, minus 2 bedrooms?? ICF wall dividing 2 500' loops from 2 other 500' loops. I just haven't heard of slinkies under a house.

ChrisJ

Posted By Dana1 on 06 Nov 2012 12:42 PM
The whole notion of burning propane even as a backup just doesn't feel right- methinks you're over-thinking/over-designing the mechanicals here. But if you're going to burn propane, with your radiation and heat loads a Polaris or Vertex water heater (with heat exchanger) are probably a more appropriate solution.

We're pretty far out in the sticks. We can use electric, (which frankly is not that reliable in the winter) propane which is then next best, a pellet stove but that requires using the generator when the power goes out. So...that's the sole reason to have over thunk this redundant heating system. A PV system is in the overall design but that's a big chunk of change we can't get to right now. I'll check into the Vertex/Polaris units. Thanks

It's all a matter of what you are used to.  I've been in a number of multimillion dollar designer homes with minisplit heads sticking out of the wall.  Even Italian designers work with them.

You can also get cassette units that are contained in the ceiling cavity and are flush mount.

I like the Polaris units but from what I see, they are pretty expensive but seem like they would work well. If I went this route, I could at the very least get up and running quite quickly.

Talking with my energy guy, he still seems to think I should just install the geo exchange heat pump, one mini coil on the 3rd floor and get up and running. This will then produce both heating, cooling and hot water but I'm concerened on where the hot water is stored unless I get the Vertex or a polaris tanks set up or use a hot water tank for storage. This makes me think my machine room will look like a maze of piping.... Any thoughts?

Posted By Roundeye on 15 Nov 2012 01:06 PM
I like the Polaris units but from what I see, they are pretty expensive but seem like they would work well. If I went this route, I could at the very least get up and running quite quickly.

Talking with my energy guy, he still seems to think I should just install the geo exchange heat pump, one mini coil on the 3rd floor and get up and running. This will then produce both heating, cooling and hot water but I'm concerened on where the hot water is stored unless I get the Vertex or a polaris tanks set up or use a hot water tank for storage. This makes me think my machine room will look like a maze of piping.... Any thoughts?

If you do go with the geo, a separate tank is needed aside from the gas tank. Two heat sources in one tank is not easy to control unless the control is in the HP and it is set up for both. Get a storage tank for the geo. 

If I use the HP to heat domestic hot water, is the recovery rate as good as a propane unit? We have a 40 gallon propane water heater now and it's impossible to run out of hot water for the most part.

recovery is slower. to achieve the same performance, you store more volume.

HP for DHW?

The average cost for DHW is so low as to make it hard to justify anything but tank-type heater (We install solar, tankless, condensing, even HP, etc.)

There are other reasons to switch to Greener hot water, but performance is rarely one of them.

We design many home heating systems using Polaris for space and DHW but that is integration and is in different class.

HP for DHW?
Yes, the geoexchange heat pump is supposed to produce DHWater from what I understand.

I like the Polaris unit as a back up for propane heating of the house as a redundant system to the geoexchange HP but it sounds like I many need 2 tanks and the integrations/logistics might be a bit difficult.

docjenser has used the water to water HP for radiant and DHW, here is a welserver site that shows one.

http://welserver.com/WEL0383/

That system doesn't have air coil for a/c, but there must be a reversing valve set up to change the radiant to cool water in the summer.

ChrisJ

Good info ChrisJ.
There were quite a few sites monitored on the weserver. Cool link. Thank you.