How to heat your house with cold water (and a little electricity)
No doubt most of us by now know about air to air heat pumps for heating our houses. Seems to me they’ve been around forever, after all, widespread distribution of the first refrigerators was back in 1927. Gaining popularity for both commercial and home use are geothermal heat pumps. The difference here is that you include a loop of pipes filled with water or anti-freeze run into the ground near your house. What this does is suck up a bunch of heat from a large area. I had one at my house in Wakefield. It used cold water from the well to heat the house. It was an open loop system which meant the water drained back down the hill after I sucked a few degrees of heat out of it.
So the way it works is really quite simple, you have a source of constant temperature water year round. The water might be cold (8 to 10 degrees C) however, it still has some warmth in it before it will freeze. So you run it through your heat pump and out comes water that’s a few degrees cooler. So where does the heat come from? The water. For every 1 unit of electricity put into running the heat pump, you get 3 units of heat out of the ground, producing 4 units total by the system. I was often asked, “How efficient is it?” The answer is usually unexpected. It’s not 100% efficient, it’s like 400% efficient. This usually starts some argument that I don’t know what I’m talking about, but the proof is in the dollars spent running the system. Instead of costing me $1400 to $1800 a year to heat and cool the house, it became more like $400 to $600. Less energy is being consumed from hydro Quebec, more is being used from the warm ground around your house. If I were to get another one, I’d go for a closed loop system. Preferably the loop would run into a pond or river instead of the ground (cheaper to install).
WaterFurnace has a nice pamphlet describing the way it works.
Ground source is definately the way to go – and closed loop if you have the space.
My parents (open loop) and brother (return well) have used them since the early 90’sboth have total energy bills less than 1K/year. My brother very much less because he also super insulated and designed for passive solar.
The only drawback is the high initial cost for the furnace, well(s) or loops – but costs are paid back very quickly – and the life expectancy is longer than a standard furnace/airconditioner combo.
We’re going to add one to out cottage soon. Can’t do anything downtown.
Yeah, Peter – don’t start drilling downtown, you might hit an oil pipeline!
Thanks for this post. I’ve been thinking that there must be better heating solutions that can reduce our carbon footprint on the environment. I’m going to look into installing such a furnace in our home.