While portable storage buildings allow for some air circulation, a shelter may need additional ventilation, especially if it’s storing a seasonal vehicle like a boat or RV. One option to allow more air circulation is to install a vent into the polyethylene canopy at the back of the structure. This way, both heat and condensation can exit the structure easily and cleaner air can circulate around inside. Stores like Shelters of America and Portable Garage Depot sell such vent kits that allow you to allow a plastic vent to the back of a canopy structure. Once you have such a kit, you can cut a hole in the polyethylene canopy and follow the installation instructions for adding a vent.
In general, a vent kit comes with two durable injection molded vents. These plastic vents are designed with UV protection and weather resistant resins. This way, the vent won’t be damaged when outside for an extended period of time. Each vent comes with pre-drilled holes so that it can be attached to the canopy easily with basic hardware. As mentioned before, a hole large enough for the vent will need to be cut into the polyethylene material. Additionally, two vents can be used at once, depending on your or the shelter’s needs, or one can be used as a replacement.
Why would a canopy need a vent? Although canopies are designed to be waterproof and mildew and rot resistant, some water still may find its way inside the shelter. Without enough ventilation, the shelter could cause dry rot or mildew to build up on a vehicle while in storage for several months. Although canopy shelters like portable garages and sheds allow for some circulation, additional ventilation may be needed for a shelter. Adding one or two vents to a portable garage will allow additional circulation to lessen the chance or dry rot or mildew building up on a vehicle.