New Home

[Rgator]

Hello, I am building my new home and have reached the point to make the decision on the heating system.
My thoughts are to install a wood boiler and a propane boiler backup.

Here are the particulars:

Location is Maryland
4000 sq. ft. Timber Frame
Open floor plan
Insulation:
R30 walls
R40 roof
R13 basement
Radiant in floor heating
Mini-splits for AC

Questions:

1.) Thermal storage tank style systems vs. a Garn vs. Geothermal (pond loop)
2.) Type of flue to install. New construction so I can install masonry or metal.
3.) Location of the wood boiler. Basement or attached garage?
4.) How to create the domestic hot water?
5.) ROI, the balance of the cost versus return, or should I say term of return? Some of the
technology that is available is so costly that the ROI is ridiculous. I believe you have to reach a balance.

I realize that there is a lot of personal preference involved in these decisions but there is a tremendous amount of information to be learned from people who have been there and done that. I would appreciate any input, good, bad or indifferent no harm no foul.

Respectfully,

Ron

 

[Boil&Toil]

Heck, in Maryland you should be able to get a lot of effective heating milage out of a good (COP, SEER, etc) set of mini-splits. At which point the rest of the heating system should be fairly limited, since you care about ROI.

Heat pump water heater will save AC money all AC season and pretty much move heat around from your other heaters to your hot water in heating season. Though if you actually do put in a boiler you can certainly run a sidearm or something to directly heat the hot water as well.

Wait-a-minute - pond geothermal is an option? Put in a water to water heat pump, switchable so you can run chilled water for A/C while desuperheating for hot water, or make hot water for heat & hot water. Put in a wood stove just for power outages or ambiance and laugh all the way to the bank...

 

[Floydian]

Hello Ron and welcome!

Step one is a heat load calculation. A must for properly sizing any heating or cooling system.

What you really want to know is your heat loss in Btu/hr at your outdoor design temp. Once you have this you can estimate your annual heating load to get an idea of what it might cost you in time/money to heat your house. Run the cooling load as well, which should be fairly small unless you have lots of unshaded west facing windows or south facing with inadequate overhangs.

FWIW, I agree with Boil&Toil. Mini splits for heating and cooling are going to be hard to beat. A wood stove to help out when colder weather sets in and the ultimate in simple backup heating.

For DHW, heat pump water heaters are looking good performance wise and adding some PV solar to offset usage could be a good ROI as well.

Radiant floors are nice and all but in high performance houses they really wont feel very warm except in the coldest weather but one thing for sure, to do it right takes a lot of dough.

Again, gotta do the math.

Noah

 

[Rgator]

In a Timber Frame duct work is near impossible (visual deterrent) so the mini splits are the ticket for AC/heat backup and radiant in floor is the answer for heat. My last 2 homes were radiant and I love it. So those are the distribution systems, now I need to pick the supply. I understand that GSHP are very expensive and do not actually function at the COP advertised due to lack of pump calculation losses etc. In my climate I think the ASHP will do a good job at a fraction of the cost of an GSHP. But, I do have the pond for the loop and with the tax incentives I will look into this.
I completely agree about the heat load calculations, that is in the works.

Who makes ground source heat pumps that are ductless?

Ron

 

[peakbagger]

Generally ground sources are water to air but I believe Water Furnace makes a water to water ground source. I don't have any experience with them but that names pops up frequently.

 

[maple1]

Nothing said about a pretty important detail - the local fuel situation.

NG? Pellets? Wood? Costs?

 

[STIHLY DAN]

Who makes ground source heat pumps that are ductless?
Ron

No one.

 

[maple1]

Water Furnace has several hydronic geothermal heat pumps on their web site.

Depends what you'd call 'ductless' - but I think I'd call those ductless.

 

[nwomatt]

Heat pumps are great if you like paying hydro. The compressor typically is on a 50 amp brkr. That would be be the biggest one in the house next to an electric furnace. With a milder climate might be not too bad.

 

[STIHLY DAN]

Ductless splits run on modulating compressors, typically less than 10 amps, obviously size matters.

 

[peakbagger]

I guess to comes down to definitions. If the OP is looking for something like a minisplit that uses a water loop for the outside unit and an air handler like a mini split on the inside, I haven't been able to find one as I looked for one for several years on and off. I expect a tech could replace the outdoor coil of a mini split with a water to refrigerant heat exchanger but haven't seen anyone doing it.