Let’s take another look at what we’re dealing with.

Back when we first toured our house, before we finally bought it, the seller kept going on about the heating system: radiant floor [1] this, hydronic baseboard [2] that. To be honest, I had no idea what he was talking about. Growing up, I spent my winters sitting in front of a heating vent in the kitchen, not caring where the hot air came from, only that it came. (Ah, the sweet and totally-not-green obliviousness of youth.) In those days of my pre-mechanical mind, I had it mapped out something like: Furnace turn on, hot air come; hot air good.

That is, I think, about where most people stop when thinking about how their homes get heated. Which is why most Americans are saddled with a mostly inefficient and kind of stupid way of heating their homes: forced air. You’ve seen its metal vents in your neighbor’s house; you’ve felt its hot breath at the mall. Forced air heating is pretty straightforward: A furnace (gas, oil, electric) heats up air, usually to well over 100 degrees, and a big fan blows that air through metal ducts and into your living room and kitchen and ladies’ boudoir.

[* This is not my dog. It belongs to this nice lady [3].]

But think about the volume [4] of your house. Say you’re living in 3,000 square feet, with 8-foot ceilings. That’s about 24,000 cubic feet that you’re trying to heat. Now. All at once. That’s a lot to ask. And forcing hot air around your living space creates a number of problems: It pressurizes the inside of your house, pushing air out any crevice or crack it can find – like that gap between your front door and the doorjamb. That’s lost warmth, and lost energy. It also blows a lot of dust and other allergens around your living space, which is particularly a problem for those of us with kids or with greater naso-bronchial sensitivities.

But to me the most egregious fault of forced air systems is that the damn vents are in (or near) the floor. What’s the most basic property about hot air that everyone knows? It rises [5]. Forced air heating even gives it a little push, so it can rise right to the ceiling, where it’ll stay until it cools and sinks down to where you’re sitting, shivering in a chair with a blanket on your lap: Better turn up the thermostat. Which is, actually, what a lot of people do. Even when it’s warmer, blown air has a way of feeling cooler than air that is still. But the beauty of summer breezes is the bane of furnace-fed winter heating.

Yet most American homes – 62 percent, according to Dan Chiras [6] – run forced-air systems. Why? I don’t know. Maybe the obviousness of it is comforting: Hot air good. But there are better ways – much better – and I’m going to tell you about them. Next week, after I’ve reined in this high horse [7] of heating I’ve been riding.

Also, I’ve been messing with Google’s SketchUp [8] design app, so hopefully sometime soon I can start posting some diagrams and floor plans and whatnot to help you see what wondrous work we're doing over here. Here's a hint:

One other thing: Last week, Jed [8] asked about heating my home with a pellet stove. Pellet stoves [9] are pretty clever – basically, a little hopper feeds pellets made of compressed wood into a stove, they catch on fire, and the heated air is then blown into the living space via little electric fans. Sort of a rootsier forced-air system. The pellets can be made of waste wood or biomass – corn stalks, cherry pits, whatever – giving them the added element of reuse cool. Us, we’ve already got the miles of copper pipes twisting through our joists, and I couldn’t find anything – any commercial products, anyway – that combined pellet power with radiant heating systems. That’s not to say it can’t be done: Tom Elpel [10], whose book [11] I mentioned [11] a couple of weeks ago, cobbled together a domestic hot water heating system that runs off his kitchen cookstove. His family uses the wood-fired stove for cooking meals and heating the house, so the thing’s fired up for much of the day. Tom ran a coil of copper pipe from a cold-water supply through his cookstove, allowing the water to pull heat from the wood fire before it heads to an insulated storage tank. The Elpels use that water for showers and washing dishes. Added bonus: Thanks to something called thermosiphoning [12], Tom’s system requires no electric pumps. Primitive but perfect. When I finally shed this consumerist coil and build my off-the-grid minster, stove-based radiant heat will be the first anti-mod con I install. But for now, efficacy and efficiency dictate a new, natural-gas-fired boiler.