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Winning Heat

For probably the last six weeks I've been reading everything I could find on heating systems and re-reading stuff I'd read all year, trying to decide what to do.

Maybe it wouldn't be so hard if not for economics. After meeting with the heating and plumbing people, we leaned towards putting radiant heat on two floors. Friends have talked about how great it is, and we already have the tubing in place in the basement slab. And since our furnace stopped working this winter, it made sense to switch over from a propane forced hot air furnace to a hot water-based system. We could have an indirect hot water tank attached to it and get the benefit of more efficient and cheaper hot water. So we got estimates for radiant on two floors, radiant on one floor and hot water baseboard heat on the other, and baseboard heat on both floors.

I was gung ho and excited till the estimates came back: $25,000 for radiant on both floors, $17,400 for baseboard on both floors or radiant on the bottom floor and baseboard above. We went back and got a price for a new propane furnace and ductwork, which came to $9,500.

Way too many late-night conversations and popping aspirin followed. In the end, what helped most was Alex Wilson's book Your Green Home, one of the best general guides for the person like myself who needs help sorting out questions like these. I'm paraphrasing, but the gist of his argument was this: If you're investing in good insulation and windows, passive solar design, et cetera, you shouldn't need that much heat--so why are you spending a ton of money on a super-duper heating system?

He even posits that in a green house, radiant often isn't a good fit. Why? There are several reasons: One is that in a house like ours, with passive solar, you may only need heat periodically. But the radiant floors are relatively slow to heat up and cool down, so if it's cloudy and you turn up the heat, it may not warm up till it's already sunny again. In our case, it's even more of an issue, because the bottom floor is for our studies. We need something we can turn up when we're down there, and turn down when we leave. And I tend to like a room cooler than Chum does. That makes even a central propane system somewhat problematic. It's hard to steer the heat to just one spot with a furnace like this, since heat will leak around closed vents.

So what are we ending up with? The HVAC guys (and anybody thinking about resale value) no doubt think it's an odd choice--but I hope it's the right choice for us. For the main floor, we're putting in a smaller, high-efficiency (92 percent efficient) Bryant forced air propane furnace similar to what we had. Like with the old one, it'll also heat the upstairs--the heat rises up the staircase. We're also planning to put Rinnai vented propane space heaters in each study downstairs. That gives us more control over the individual offices, and we can keep them heated minimally when we're not using them.

I felt really good all week having decided this, though this morning when I woke up I started second guessing myself again. If we get solar hot water in the future, a hot water system would make so much sense, plus we'd already have the indirect water tank in place, and so on. My head is starting to swim all over again...

© The Green Guide, 2008

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