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April Downs
Geothermal - should I do this?

Considering retrofitting my 1906 house for geothermal. I live in Maryland, near DC so the climate is not extreme - little hot in the summer. The retrofit will include having duct work put in my old walls. The horsehair plaster is pretty bad anyway and covered in most rooms with dry wall. Currently paying about $5000/year for oil heat and hot water so even a $25000 system could pay off in about 5 years. Also there is a lot of federal, state and county tax breaks making this a $15000 retrofit. My current concern is giving up my nice warm radiators for a vent blowing warm air at us - far less effective heating - right?
Looking for experience others have had with leaving radiators for forced air heat and with digging up your yard for geothermal. Any regrets??

Re: Geothermal - should I do this?

There are a lot of things to consider with this. Number one the payoff. If you spend $5000 a year now and the system cost $25000 you still have to consider the cost of running the new system the new one may cost you $2000 a year in electricity to run every year pushing that payoff to more like 8 1/2 years.

The second thing to consider is the type of geothermal. I have a friend that put in a open loop system were it uses the same drilled well as his homes water to feed the geothermal. It uses a variable speed pump to keep a consistent pressure. And no digging up the yard and paying for an excavator.

Third you can get Geothermal Radiant heating. I know two people who have this one was a retrofit into an existing home and one was a new installation. I can't speak to the cost difference in the forced air vs. radiant.

And Forth. The Rebates read the fine print my friend that put in the new system in a new house found out the rebates only applied if he put in a separate pump for heating and cooling. that added another $5000 to the installation. So the rebate ended up being a wash. He got a more efficient system but didn't really get the savings he was expecting. Just double check that before you make the commitment.

Re: Geothermal - should I do this?

You have to carefully check out the fine print on the rebate requirements before you decide to jump into such a project.

Re: Geothermal - should I do this?

First, your house should be efficient (well insulated) to begin with, otherwise you are going to need a large heat pump, and then it won't be cost effective. It also works only with duct work or radiant, but not with baseboard heating.

I had an open loop geothermal system installed 4.5 years ago in a new house. It is a 4 ton system for an 1800 s.f. house that is energy star certified. My yearly bills for heating, AC, and hot water has been $600 - $700 (I can tell because I have the heating components on a separate meter). Not bad since I live in northern NH. Geothermal provides both heating and AC (no AC obviously if radiant floor), and if you have a desuperheater (think most of them come with it), then it assists with the hot water as well. Mine is a Climate Master. You need a certified installer. It is very important that it is sized correctly. There is almost no maintenance other than changing an air filter every 6-12 months.

If you have a well, it can be probably be retrofitted for a new system although you may need to get it drilled deeper. You need about 100-150 feet of depth for each "ton" rating of the heat pump. My well is 600 feet. There are other setups as well, e.g 4 wells of 150 feet each, or even horizontal layouts if you have the land to support it. You can also use an antifreeze type agent in place of water.

I've been very happy with my system so far. Don't have to worry about crazy price fluctuations of petroleum products.

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