I suggest you add air sourced heat pumps to your list of options. Carrier has the Greenspeed model which uses inverter technology making the efficiency close to Geothermal heat pumps. If you also look at Trane/American Standard heat pumps. They have the defrost on demand feature which would be desirable for your location.

If you are going to have a propane tank, then you could consider getting a dual fuel system. This would be using a high efficiency furnace with a heat pump. It would also set you up for a conversion to natural gas if and when it became available.

I would not give up on propane just yet. You need a large buried tank, say 1000 gal. That should carry you through the season. You could then have radiant heat with a high efficiency boiler when it is really cold. Coupled to that you install mini split heat pumps for your cooling/dehu needs. As well, they will provide most of your heat in Sept, Oct, Nov and likely into Dec. You will get late Feb, March, April &May "almost " completely with the very efficient operation of the mshp. The mshp are very close to the efficiency of the geothermal at a fraction of the cost.

Yes, I forgot to mention the Greenspeed by carrier. Thanks for the suggestion.

We are planning on burying a larger propane tank in case we needed it for hot water as well as cooking.

The issue with propane is monetary. Let's take a 1,000 gallon fillup as a seasons worth. At current RI prices that comes out to nearly $4,600. Also, prices are only increasing. We really don't want to be locked into propane prices.

For example a pellet system could easily heat our 2,000 square foot house with unfinished basement for 40% of that $4,600.

What is electric rate?

If this is rural area and prone to power outages during winter weather, propane could be used for backup generator to power an all electric heat system. Just a thought.

IMO

Thanks for the suggestion tigerdunes, putting a propane powered generator on a slab is part of our plans.

The electric rate is 7.831â/kWh2.

Your electric rate is less than half of what I pay in NJ. It makes the most sense to go with the heat pump. If you spend the extra money on the Carrier Greenspeed, I would estimate a back propane furnace would not fire up until the temperature went below 10 degrees, and possibly lower. You would use very little propane each heating season.

I think you can do better on the propane price if you buy your own tank. Shop around for and see what you can find in your area.

WhatâÂÂs âÂÂ7.831â/kWh2.â A typo?

Well this is a âÂÂno brainerâÂÂ.

New construction and LESS than 8â/kWh - NOTHING beats geothermal! Your cost would be less than 2â/kW of heat delivered into your home with a COP of 4. The same geothermal system would also heat most of your domestic hot water as well.

You may have already missed your best opportunity to have geothermal installed as inexpensively as possible by not having the bulldozer that cleared the land bulldoze trenches for a horizontal ground loop at the same time while the equipment and operator were ALREADY on-site.

If you want to go geothermal you still have some interesting options. You could get the bulldozer back on-site, horizontal trenches could also be dug when you have an excavator on-site to dig the foundation or you can have the well driller drill the boreholes and install the vertical pipes when heâÂÂs there to drill the well. Even though I prefer closed loop, open loop may also be possible with the driller drilling a supply well for domestic water and geothermal while drilling a second well to responsibly return the water back into the same aquifer unchanged except for a few degrees in temperature, providing of course there is sufficient water of suitable quality.

At this stage you can even plan the penetrations into the envelope either through the foundation wall or straight up from the ground into the future mechanical room floor BEFORE the cement slab is even poured! ThatâÂÂs what I would, every loop coming into the mechanical room with the headers indoors for easy flushing, commissioning AND easy loop isolation & analysis down the road should a problem occur.

One thing is for sure. If you want to geothermal - NOW is the time to do it!

BTW: You mentioned heating a 2000sq ft home for $4600 with propane and about 40% less or $1840 with pellets. You could probably heat the house for even less than 40% of what the pellets will cost. We heat our 2800sq ft home in Montreal with geothermal at 8â/kWh for about $500/yr. The temperature here tomorrow is STILL going down to below -0F without the wind chill factor! The backup hasnâÂÂt been on for at least several weeks. Thought you might want to knowâ¦

IMPO

SR

Here is a link that might be useful: International Ground Source Heat Pump Association at Oklahoma State University

With that electric rate(if it is indeed correct), you have 3 choices. Budget and tax credits should be considered.

Geothermal HP
Carrier Greenspeed HP
Conventional high eff HP

4 choices if you wnt to consider ductless mini split HPs.

IMO

At a low electric rate the ROI on the price difference for a geothermal system versus the Greenspeed or conventional HP takes longer.

Pay attention to the COP and HSPF heating efficiency of rated systems you consider.

TD

Thank you for all the informative replies.

Geothermal would be our first choice but the initial investment is frightening. I just read a thread on this board quoting a $49K install without hot water and back filling the wells. That build was very similar to our, large lot and less than 2,600 square foot build.

Not sure if that includes the added expense of a backup system.

The electric rate was taken from this RI GOV website.
http://www.ripuc.org/utilityinfo/electric/narrelecschedule2.html

Also, we are hoping to build for between $150 -$175 per square foot which seems impossible if we go geothermal, sadly.

You realize there is a 30% Tax credit on Geothermal?

If not geothermal, then look at Carrier's Greenspeed system.

IMO

Yes, I know about the 30% tax credit but ultimately I'm trying to come to grips with that remaining 70% and the additional cost of a backup system.

There are a few installers in RI listed on the IGSHPA website that we will get estimates from. We hope the cost is doable.

Be aware the cost of the duct work and back up generators are not eligible for the geothermal federal tax credit.

Is a backup generator (which we're installing anyway) considered backup for a geothermal system or would a whole second type of heating system need to be installed?

Also, are Dedicated Heat Pump Water Heaters used in conjunction with a geothermal system a viable way of providing steady hot water?

Yes, the ground source heat pump will provide hot water. You don't need backup heat with a ground source heat pump any more than someone with a fossil fuel needs a back up heat plan. The difference is that if you want it to run with an electric power outage, you need bigger generator than with a fossil-fuel heat system.