[villalobos]

Anybody on this forum has a geothermal heat pump in his house, and can comment about the efficiency of such a system? I am looking into that technology and was wondering if it could heat a small house (~1100 sq ft) in a climate like in New Jersey.

villa

[Cold Warrior]

No experience with those. I've used regular, above-ground heat pumps and hate them. In temperature extremes (<20 and >95 degrees F), they do a horrible job heating and cooling. The geothermal ones, from my cursory reading, seem like they'd perform better.

[Kevin Moon]

My parents have geothermal in IL and it works great. The heat and cooling bill stays at $40 a month no matter the temp outside. They do get a reduced rate for an all electric house which bring electric for the appliances down to 2.2 cents/kWh. Most of what is paid for electricity in the house is just lighting which is charged at 12.5 cents/kWh. Look to see if the electric company offers any discounts for installing a geotherm unit or if they off low cost loans to install them. They can be very expensive depending on how the lines have to be laid. Another thing is make sure that the lines are put down deep enough. During the drought where my parents lived many of the other houses with geotherm didn't work very well due to the lines being 5-6 ft underground.

As for how it works, during the summer when it was over 100 the unit had no problem keeping the temp at 72. In the winter you can make it as warm as you want and it will keep it there so I would say it is pretty good. Also ask for the installer to add an inexpensive part that will heat your water before being dumped into the hot water heater. That saves a lot of money over the life of the unit. The installer my parents had just put it on since it costs next to nothing to do.

Before this they had an air to air heat pump and that didn't work well ever. My parents bought the house with that and changed it out the next year. I would not recommend air-air heat pumps anywhere it drops below 20.

[villalobos]

Originally Posted by Kevin Moon 

My parents have geothermal in IL and it works great. The heat and cooling bill stays at $40 a month no matter the temp outside. They do get a reduced rate for an all electric house which bring electric for the appliances down to 2.2 cents/kWh. Most of what is paid for electricity in the house is just lighting which is charged at 12.5 cents/kWh. Look to see if the electric company offers any discounts for installing a geotherm unit or if they off low cost loans to install them. They can be very expensive depending on how the lines have to be laid. Another thing is make sure that the lines are put down deep enough. During the drought where my parents lived many of the other houses with geotherm didn't work very well due to the lines being 5-6 ft underground.

As for how it works, during the summer when it was over 100 the unit had no problem keeping the temp at 72. In the winter you can make it as warm as you want and it will keep it there so I would say it is pretty good. Also ask for the installer to add an inexpensive part that will heat your water before being dumped into the hot water heater. That saves a lot of money over the life of the unit. The installer my parents had just put it on since it costs next to nothing to do.

Before this they had an air to air heat pump and that didn't work well ever. My parents bought the house with that and changed it out the next year. I would not recommend air-air heat pumps anywhere it drops below 20.

thanks for the reply! That seems indeed very interesting. Any idea of the installation cost (ballpark). Also did they have an horizontal installation or vertical (depending on how much land they have). It would probably have to be vertical in my case given the small lot my future house will have. I have to say $40 a month seems VERY attractive! It might be expensive at first, but it would add value to the house in case of resale as well (I have not even closed yet that I am thinking about resale already!!).

[asttro]

Originally Posted by villalobos 

Anybody on this forum has a geothermal heat pump in his house, and can comment about the efficiency of such a system? I am looking into that technology and was wondering if it could heat a small house (~1100 sq ft) in a climate like in New Jersey.

villa

Hi, I live in PA, right on the NJ border across from Lambertville. I researched geothermal extensively and had one installed in my home. The technology is ideal for our climate and a small home will be no problem.
Keep in mind that you should start with good weatherization of your home. At least R-40 in your attic, as much as you can get in the walls, high-quality, air tight, low-e argon filled windows on the E, W and N sides of the house. Ductwork should also be checked and air-sealed.

On larger houses, the geothermal will pay for itself in reduced utility bills (assuming that it's paid for on the initial mortgage). As a retrofit, they are very expensive in our area. The problem is that there are very few QUALIFIED installers around. And you need a highly skilled installer. My system was installed by a total hack and is not running optimally. In spite of this, it greatly reduced my utility bills. Again, if you go geothermal, make sure that your installer is amply qualified and get in writing the performance characteristics of the system. There should be some wording in the contract like "the system is guaranteed to produce a minimum of xxx BTUs/hr during winter use". This is critical because often installers skimp on loop sizing which leads to excessive ground cooling around the heat exchange loops. This results in the system being less efficient and unable to supply the desired amount of heat.

Pricing will not be cheap. Your home is very small, so the heat load shouldn't be more than a couple tons (i.e. 24000-30000 BTU/hr) if it has any insulation. Yet the installation costs will largely be as much as for a big system. So you might spend $15-$20,000 on a system. Be suspicious if anybody says they'll install a system for much less than this.

There's lots more considerations. See my profile and web address. You can contact me directly from there. If you're nearby, I'll talk your ear off about all you need ot know.
-Ted

[design219]

Originally Posted by villalobos 

Anybody on this forum has a geothermal heat pump in his house, and can comment about the efficiency of such a system? I am looking into that technology and was wondering if it could heat a small house (~1100 sq ft) in a climate like in New Jersey.

Yes, I built an extremely efficient house two years ago with a geothermal system. The heating an cooling are fantastic, but the whole house is a system. Passive solar design built with structural insullated panels.

Our house is 2,750 sq.ft. and we have a two speed Waterfurnace system that can run at 1.5 ton and 3 ton. We also have a fresh air exchanger with the unit so we don't have the stale air situation that tightly sealed houses can have. Fresh air is introduced into the unit.

The results are fantastic! The system runs constantly with a very gentle flow, so when you put your hand over a vent, you just feel a little air movement, but never a draft anywhere in the house. The constant air flow means it is always the exact same temp (74) upstairs and down, any room.

As far as costs, our total electric bills average about $80 month, and never been over $100. That is for a family of 4. The house has three full baths, two floors and a tower. All appliances are energy star (except for a gas cook top which we use propane.) We also have a high efficiency wood stove, but have never used it yet. We do not get any special rate for have efficient heating/cooling.

I can't give all the credit to the geothermal, because our architect designed the house so well (again, high insulation values, passive solar design, efficient hot water system, etc.)

I also live further south (Kentucky) but from what I've read, geothermal systems work well just about anywhere.

[Kevin Moon]

Originally Posted by villalobos 

thanks for the reply! That seems indeed very interesting. Any idea of the installation cost (ballpark). Also did they have an horizontal installation or vertical (depending on how much land they have). It would probably have to be vertical in my case given the small lot my future house will have. I have to say $40 a month seems VERY attractive! It might be expensive at first, but it would add value to the house in case of resale as well (I have not even closed yet that I am thinking about resale already!!).

I think the unit ended up costing around 10k but will more than pay for itself in bills and added value to the house. They bought the unit before the price increases and I think the same unit is around 15k now. They went with loops which they put extra out just because we had the room. They have 4 acres so the installer just decided to run extra loops some of which go out a few hundred feet then come back. A vertical hole does add cost but even with a small lot they can sometimes run loops. My parents live in the country which makes the $40 to heat/cool the house unheard of. They participate in a load control program run by the electric coop which is why the rates for electric are so low. The electric company shuts the water heater down around 10 am and the ac compressor is cycled in 15 min intervals. The hot water after 10 am is heated by the geothermal and it stays fairly hot throughout the day. They only do the load control during peak demand times and you can't tell anything is off or running less, that shows how efficient those systems really are. I really recommend talking with the power company as a lot of them offer reduced rates or very low-no interest loans for geothermal installation.

Just find an installer that has the qualifications to install a geothermal unit and one that you feel you can trust.

[G4ME]

Originally Posted by design219 

The constant air flow means it is always the exact same temp (74) upstairs and down, any room.

thats disgustingly hot, winters nothing above 65 for me please.

Probably another reason i wont move south of Taxachusetts

[design219]

Originally Posted by G4ME 

thats disgustingly hot, winters nothing above 65 for me please.

Probably another reason i wont move south of Taxachusetts

The humidity is kept below 50%, so it feels good to us. A cooler temp would be fine, but one of the keys to energy saving is to not keep changing the thermostat up and down. That is often hard to do in a house that is not well insulated or well sealed.

[G4ME]

umm yeah or you could just leave it at 64 and call it good

[design219]

Too cool for me. (my life story)

[villalobos]

Thanks for all the replies. I will try and see what type of quote I can get. The state of NJ subsidizes to a small extent these kinds of installation ($500 per installed ton) for those who are interested.

[villalobos]

Originally Posted by design219 

Too cool for me. (my life story)

Don't feed the trolls. :-)

[Mastrap]

Originally Posted by design219 

The humidity is kept below 50%, so it feels good to us. A cooler temp would be fine, but one of the keys to energy saving is to not keep changing the thermostat up and down. That is often hard to do in a house that is not well insulated or well sealed.

The energy cost you're quoting are very low for keeping the house at what is a pretty high temperature in winter - good to know. We own a property that has the required amount of land for a geothermal system. The house build on it is an old cottage of no particular architectural merit. My wife and I have been discussing the possibility of demolishing it and building a new, highly energy efficient home instead. This is all good information, thanks for sharing.

[design219]

Originally Posted by Mastrap 

This is all good information, thanks for sharing.

I've become a bit of an evangelist for energy efficient home building. If I you want any more info about our project, or experiences I would be more than happy to discuss with you. Good luck with your project.

[memento]

My air-to-air heat pump failed a few years back. I looked at installing a geothermal, because they are definitely better. It was not financially beneficial for me to do it. The cost was $12k-$15k MORE than replacing my existing. Doing the math, my ROI was way too far out to justify it. Like 15 years out.

New installation is different. You already have equipment and construction activity going on. Retrofit was out of the question.

BTW, we keep our house at 61 in the winter. 63 tops.

[Cold Warrior]

That's cold. I could handle it, but my wife would not. She keeps it at 75 in the winter. Good thing we moved to a more temperate area recently.

However, we may move up north in 3-5 years, and I've wondered about a gas-powered furnace. Anyone with comments on that? It seems like an efficient way to get a lot of hot air in the house cheaper than an air heat pump in sub-20 temps.

[Mastrap]

Originally Posted by memento 

BTW, we keep our house at 61 in the winter. 63 tops.

That's pretty much what we do too. I can't stand feeling too warm in winter*.




*This is only my personal opinion. I appreciate that we're all different.

[Mastrap]

Originally Posted by Cold Warrior 

However, we may move up north in 3-5 years, and I've wondered about a gas-powered furnace. Anyone with comments on that? It seems like an efficient way to get a lot of hot air in the house cheaper than an air heat pump in sub-20 temps.

We have a propane powered furnace in our weekend home. It's pretty efficient and heats the house up very quickly. However, we also have a wood burning stove in the same room where the main furnace air intake is. So by just running the fan but not the furnace the wood burner heats the entire house.

[memento]

I know people who keep their house at 74. Their choice. My wife and I dress warm when we go out, then when we get home the last thing we want to do is have to put on shorts and a tank top.

If you're moving up north and have natural gas to the house, it is one of the cleanest and most efficient sources of fuel. There are all kinds of ways to cut long-term costs that you can consider. It all depends on what you want to spend in the near term. Mastrap's wood stove arrangement is great.

The short answer is that I wouldn't recommend an air heat pump for someone living where winter involves a decent amount of snow. But I would still recommend a geothermal if it was not cost-prohibitive.