Garage heat doesnt have to be expensive. You basically have two choices when it comes to heat for your garage:
Depending on the current market price, electric heat is typically more expensive to produce than gas heat. The nice thing about electric heat is that you can basically plug the heater unit into your standard 120-volt receptacle, turn it on, and you have instant heat. However, more garage heat requires a higher voltage, so if you want to heat a bigger area, you may need a 240-volt receptacle to plug into.
The most popular gas heaters run on natural gas. Again, depending on the current market price, natural gas is usually considered the most efficient heating fuel. In areas where natural gas isnt available, you can get a heater that runs on liquid petroleum, or LP gas for your garage heat. Unfortunately, LP gas is usually a bit more expensive than natural gas. Natural gas and LP heaters require gas to be piped into your garage. Unless youre a plumber, this can become very expensive, although in the long, long, long run, the piping labor may pay for itself compared to the cost of electric heat.
With these types of gas heaters, ventilation is definitely necessary. This is because when the gas ignites, it gives off carbon monoxide. Some gas heaters come with ducting that needs to be installed through a hole in your garage, while other heaters dont come with any and you must come up with your own ventilation system. You can also get gas heaters in the form of propane and kerosene. In both cases, you will need to purchase a storage tank for the fuel. Kerosene emits a fairly strong odor, whereas propane is practically odor free.
Both electric and gas heaters can be fan forced, radiant, infrared, convection, or combination of either. Actually, radiant and infrared is pretty much the same thing in terms of heaters. These types of heaters are economical because instead of heating the surrounding air, they only heat the nearby people and objects. Radiant heaters have heating elements that glow and emit infrared light. This creates a situation where a nearby object becomes heated by rays from the infrared source. They arent designed to heat your entire garage. Instead, they will heat only the area being used. They are perfect for above your workbench area.
Convection heaters use a heating element to heat the air. The heated air escapes at the top of the element. Because warm air rises, cooler air replaces it at the bottom of the element. Then, the cooler air gets heated and the cycle continues.
Insulating your garage will significantly help keep it warmer throughout the winter. Its also helpful to try and keep your garage door closed as much as possible so the garage heat cant escape as often.