A warm solution for a cold workshop
I have a 22-by-41-foot garage attached to my house. It's insulated, but I'm getting tired of being out there in the cold. What do you suggest as a way to heat the space while I'm doing woodworking projects and fixing my car?
—Frank Graczyk, New Lenox, Illinois
Richard Trethewey replies: First, let's cross off all the garage-heating options that you should not be considering.
Extending the ducts from your existing heating system could draw car exhaust and carbon monoxide into the house, not to mention sanding dust and fumes from finishes. Portable electric space heaters don't have the capacity to heat an area that large and would be a hazard around sawdust. Portable kerosene, oil, or propane heaters dump moisture, soot, and carbon monoxide into the air as they burn; apart from their negative effect on your health, the moisture they create won't be good for your wood or your finishes. Wood stoves would thrive on your scraps, but it takes them a while to heat up and they wouldn't be the safest things to have around wood dust and fumes. The same concerns apply to pellet stoves.
Here are a couple of options that aren't affected by dust or fumes, will heat large spaces, and won't degrade indoor air quality.
1. Sealed-combustion space heater. One of these direct-vent units, such as ones made by Empire Comfort Systems, could work nicely if your house is already served by natural gas or propane. Its combustion chamber draws air from outside, so you don't have to worry about it sucking in wood dust or sucking oxygen out of the garage, and it vents exhaust to the outside, so it doesn't pollute indoor air. To connect its vents, it has to be located next to an exterior wall. I'd recommend getting a wall-mounted unit instead of one that sits on the floor, because it's less likely to get clobbered when you move lumber around. These appliances supply warmth quickly, which is ideal for your situation. Check with a local heating contractor to determine how much capacity—in Btus—you'll need.
2. Electric radiant ceiling panels. These units, such as the Enerjoy panels made by SSHC, can be mounted to an existing ceiling, dropped into a suspended ceiling grid, or even mounted on a wall. They're about 1 inch thick and up to 2 by 8 feet in size. These panels warm objects, not air, so they're quite effective in large, open spaces. But unlike a radiant floor heat system, the panels bring up the temperature fairly quickly; you turn them on half an hour or so before you plan to work in the shop, then turn them off when you're done. They don't make any noise and aren't particularly difficult to install. If you want, just park them near the areas where you spend the most time. Electric heating can be expensive if it's on all the time, but when you're not using it, it's not costing you money.
You can combine both these systems, too. A sealed-combustion heater would cover general heating needs, and an electric radiant panel mounted near your workbench would keep you extra toasty.