It’s not something that most people think about when they think about their garage. But since so many people spent a lot of time in their garage, it’s something worth discussing.
First you have to think about insulation. At least 4 inches is recommended other wise it’s a complete waste of energy trying to keep the place warm. And we dont’ just mean the garage door, we mean the ceilings and walls. Installing insulation is just about the easiest thing out there, but you need to wear gloves and a mask and goggles. There are installation kits out there that are made specifically for garages.
First you have to think about what fuel you’re going to use to heat. There is propane, natural gas, Electric are the biggest. I myself have found natural gas to be the best, though I live in Texas. There are two main types of natural gas heaters on the market. One is called “forced-air” and the other is “low intensity”. Both are pretty good In my opinion, but the forced air ones do indeed push the air around noticeably, so if your garage is dusty it could be a problem. However, the forced air variety are pretty cheap.
There is a “high-intensity” type of heater as well but I do not recommend those. They are the ones that have coils that glow a little.