Water Furnace

A different approach. Just wondering if you guys have seen it and what you think. 70% is a big #.

http://www.waterfurnace.com/comfort_systems.aspx

I came across that site on my late night energy saving google searches. Geothermal requires a big investment. A retro fit might be out of reach for a lot of us. However if you were building a new house I think it would be the way to go. You can just add it to the price of the home, where would need a heating / cooling system anyway. Don’t forget… a nice warm coal stove in your living room. You can’t beat coal heat.

I have a friend from a few years ago that did exactly that. He has a loop in his ground in his brand new house. He swore by it, but at the time I wasn’t interesting in heating at all. I just used whatever my apartment had at the time. I want to run into him again and talk about it. (he had a big fireplace, yuck!)

Big investment but I'm sure its worth it down the road. My understanding is they have limited capacity though and are better suited for mild climates as the only source of heat.

The local county government here has started construction on a new library branch. It's a "green" design. Solar hot water heater panels and geothermal heating and A/C. The claim is the energy savings vs. an air sourced heat pump will pay for the higher construction costs within 5 years. There's no natural gas available and heating with oil would cost more because it doesn't have much in common with the required A/C system. I've got some engineering friends in the county government and I'll give a report on how good it is once it's up and running. It will use two vertical pipe loop wells. A test well was drilled to get the needed engineering data, underground water temps, heat sink/source capability, etc. It should work well if they spec quality pumps, compressors, etc.

I considered geothermal - simply the way to go for cooling, but for heating... I spoke to a builder who put a geothermal in his current home and he does not like it. He told me that it takes a long time for him to warm up after being out in the cold all day.

An acquaintance just had a 4 ton system installed in his new construction - cost him 22K! I'm spending about the same with only a 13 seer heat pump and purchasing a AHS coal gun with all the trimmings. Eventually I plan on radiant floor heat... so the geothermal really is not an option.

I guess many folks would be happy with the system... with the air temp somewhere in the neighborhood of 80 degrees in the winter at the registers, if one works out in the elements... a nice coal stove is a must.

The rule of thumb I've heard for geothermal is below 20 degrees it isn't very good. It's great for cooling and light heat loads as seen in the south but for northern states I doubt it's worth the investment.

There is no reason a heat pump system can not be designed to work in very cold climates or even produce hot temperatures. It requires two compressors. The heat production is effectively in series. One compressor and the refrigerant is chosen to work at the low outdoor temperature. A second compressor then raises the temperature even more. It's all about the equipment cost vs. operating cost trade off. When I was still designing electronics for a living, I had temperature chamber for testing circuits that could cool to -55 deg C (-67 deg F). It had three compressors in series!

By the time you do all that you could just use an electric heater

Google ‘ground source heat pumps’. They are very efficient in just about any region because they use the ground/water as a constant 55* heat source/sink. Works well with radiant systems due to its lower temperature output. Plays nice with solar hot water systems also as it will boost the lower temps during the winter months. Great to use in a new construction/major rebuild situation where they can be properly engineered into the house heating system. Think of them as a ‘supercharger’ to boost lower level heat (50*-90*) to useful level heat (120*-160*). I do agree that nothing beats a hot coal stove on a cold day to thaw you out!