If your garage heater is fueled by gas, it will need to be vented. Gas heaters require more installation steps than electric heaters or portable heaters. You don’t want toxic gases like carbon monoxide building up inside your closed space!
The type of venting system you use will depend on the instructions that come with the heater you purchased. See a professional to install and connect the gas lines. If you want to save money, you can hook up the venting system yourself.
Typical vents are usually galvanized sheet metal ducts vented through the wall or vented through the roof with a flue. The size of the duct you’ll use depends on the size of the vent flange on the heater.
You’ll want your ductwork and the flange to be of the same size. There are ductwork kits that can take some of the guesswork out of this job. Depending on where you have the heater installed, you’ll want to run the duct either through an exterior wall or through the roof.
How To Vent Your Garage?
1). Venting Through the Roof :
The idea of venting through the roof is to run your ductwork from the flange of your heater through a hole in your roof. You can use a duct elbow to connect the flange to the ductwork that you’re running up towards the ceiling.
You want to make a hole in your ceiling that is of the same diameter as your ductwork. You’ll also need an additional inch or two to get the ductwork through the roof.
You can use a marker to make a circle that is an inch or two, larger than the diameter of your ductwork on the top of your ceiling. Then, use a drill to create pilot holes for your reciprocating saw to finish the job.
To have a watertight seal, place the upper flange of the roof flashing beneath the remaining line of shingles. You want to make sure the hole is straight so that the ductwork will go through.
Insert about 24 inches of ductwork through the flange and above the shingles on your roof. The length of the ductwork above the roof depends on building codes in your area. Place a vent cap on top of the ductwork and tighten the screws. You want to make sure that all of the seams around the flashing are patched and watertight.
You can support the ductwork with straps if needed. Make sure everything is connected and tight. The exact configuration will depend on your ductwork and connections and the configuration of your venting.
2). Venting Through an Exterior Wall :
Use a 5-inch hole saw to drill a hole in your exterior wall. Run 4-inch galvanized sheet metal duct from your garage heater to the hole in the wall. You can connect pieces by inserting the crimped end into the non-crimped end. Use sheet metal screws to fasten the ends together.
Depending on how far you need to run your ductwork, you can use tin snips to trim pieces down and elbow pieces to turn corners. Use 4-inch B vent pipe inserted into the hole in the exterior wall. Connect it to your ductwork using your sheet metal screws.
The reason you use B vent pipe for the exterior wall is that it’s insulated to prevent excessive heat. You can seal all the holes with high-temperature silicone caulk. If your ductwork has to run a long way, use hanger straps to support it every five feet or so. These straps can be bent in a u-shape and connected to the garage ceiling joists.
The critical thing to keep in mind is you want a safe venting system. You want it to be of the right size for your heater, and you want to use materials that won’t get too hot or start a fire.
You want an airtight seal from the heater flange to the ductwork to the exterior hole. You want the exterior hole to be sealed and waterproofed, and to have a vent cover. You need to use the correct materials for your job and be aware of building codes in your area.
A heater can make your garage more comfortable. Having your heater appropriately installed with the proper venting can give you peace of mind and keep you safer.
The exact method you use will depend on your heater, venting kit, and garage configuration. Don’t skimp when it comes to the safety of you and your family. When in doubt, seek the help of a professional.