How to Ventilate a Detached Garage

There are many reasons to ventilate a garage and most are common sense items of concern. You will normally have exhaust fumes from motors, gas fumes, possibly fertilizers and pesticides and paint products and on and on. Then of course there is always heat in the summer months. One solution is easily done and not that expensive.

1. Pick the place for your ventilation fan so it doesn’t point in the direction where your wind normally comes from. It should be on the opposite side of the garage. Try to pick an area that doesn’t have any wiring in the wall or any serious obstructions.


2. Measure the length and width of your garage. Purchase a fan that will move that many square feet of air in a relatively short period of time. Keep in mind the fan will be in the open unlike attic fans and should have a shield covering the blades for safety. It also needs to have an automatic shuttering system so it closes when not operating.


3. Use the shutter panel to draw an outline on the wall where you will be cutting the hole for the fan. Make sure it is level and straight prior to marking the wall. Once you have the outside dimensions measure in about ¾ of an inch and make a second line that you will use for cutting the hole.


4. Drill a fairly large hole near the corner of the square you have from the inside line you just drew. Use a saber saw and cut along the inner line until you have a square hole in the wall. If you did not cut through to the outside do so at this time. (Many times the initial cut will go through the entire wall.)


5. Go outside and attach the automatic shutter to the wall over the opening. Use whatever type of screws needed to attach to the wall. Seal the shutter with acrylic caulk to protect from weather and leakage.


6. Use ½-inch plywood and cut a square that is six inches wider and longer than the fan. Put the fan on the plywood and trace the diameter with a pencil. Inside the line drill a smaller hole for the blade saw and again cut the hole out of the plywood.


7. Look at the fan housing and you will see one of the mounting brackets is marked the top. The motor does have a top and bottom and just make certain it is mounted correctly.


8. Mount the fan directly over the hole to the plywood with wood screws. If the fan has a thermostat (which it should) mount it to the plywood as well.


9. Place the fan in the hole in the wall. The shutters should be covering the outside and you can screw the plywood frame to the studs on the wall.


10. You can at this time both locate the nearest circuit box and connect to that through the studs or you can make a plug to use in the nearest socket. That would be dependent on how much you plan on using the fan.