The natural gas furnace that was in my house when I bought it was ANCIENT. It may have been installed in the 50's. So I knew that I would need to replace it. When my natural gas company wanted to change the formulation for our gas mix, they needed to get my furnace inspected. Rather than pay to get that dinosaur inspected, I decided to upgrade to a solar system for space heat. I looked at ripping up my floors to put a great product - Warm Board - in, but wow. I just didn't want a whole house remodel project that large. Then I found that an Air Handler which has an aluminum finned radiator to exchange hydronic heat to ducted air can be retrofit to my existing ductwork. Neat.
My system comprises of:
- 5 Stiebel Eltron flat plate solar collectors
Navien tankless heater which I hope I rarely ever use
Stiebel Eltron SBB600S 160 gallon Thermal Storage tank
Life Breath air handler
Axiom Pressure Pal to keep glycol levels topped off
Controls and pumps and pipe - Lots of pipe
My stystem overheated today. But no biggie. The axiom will top it off next time the pump engages.
Why this system? I had heard about evacuated tubes. They are way more efficient than flat plate collectors. They work on cloudy days. They work better at colder temperatures. If I lived in - cough - Hudson Wisconsin - cough - I would definitely use evacuated tubes. But the flat plates have another advantage. In September the sun is getting pretty close to full gain on my syetem, yet the heating season has not yet begun. My system dumps heat. Evacuated tubes don't do that. They are too efficient to dump heat. If I were to buy an evacuated tube system, I would include at least one flat plate in the system so that I could radiate heat at the moon in late summer when I am taking in too much heat.
Natural gas in Utah is WAY cheap. The economics of this system, however, will still make sense. With the incentives and tax rebates, I will have payback in 5-10 years. If gas prices go up payback will be quicker. If we care about energy independence, natural gas prices will go up as we transition from imported oil to domestic natural gas for use as a transportation fuel. If I need to buy a car before EREV cars are available I can buy a CNG car which I will be able to fuel with the natural gas I have saved. Money will stay here in Utah rather than go to the middle east, and both Al Gore and T Boone Pickens will be happy with me.
