Installing a Kitchen Exhaust Fan Cover

What You'll Need
Tape measure
Plastic cover kit or plastic visqueen
Magnets or printable magnetic sheet

Installing a kitchen exhaust fan cover is an easy and cheap way to improve the energy efficiency of your home. Installing an exhaust fan cover prevents backdrafts of cold air from entering your home during the winter months. The simplest exhaust fan cover kits are just pieces of plastic with magnets attached. Although many range hoods contain self-shutting dampers that close automatically, these dampers may have a poor seal which allows cold air to leak through. The plastic covers are incredibly cheap and easy to install; they will quickly pay for themselves in energy savings.

Step 1 – Measure Exhaust Fan Opening

Determine the size of shape of exhaust fan cover that you will need before heading to the store. Newer overhead range hoods will usually have rectangular exhaust fan openings that come in standardized sizes. Older buildings may have a circular fan mounted on the wall directly behind the range. Measure the sides and diagonals of rectangular openings or the radius of circular ones.

Step 2 – Obtain or Fabricate Kit

Search for a cover that meets your needs at a local hardware store or online. You should be able to find one for less than $10, not including shipping and handling. If you are totally unable to locate a suitable cover, the part may have been discontinued by the manufacturer or your exhaust fan opening may be of a nonstandard size. This is no reason to give up, however. You can fabricate an exhaust fan cover using plastic visqueen available from the painting section of the hardware store and printable magnetic sheets. These magnets are generally available from office supply stores; they are the same type used to print refrigerator magnets and other promotional materials for marketing campaigns. Choose plastic sheeting that is heavy enough to block airflow but light enough to be held up by household magnets.  

Step 3 – Install Vent Cover

Installing the kitchen exhaust fan cover is as simple as sticking it against the range hood or duct opening. If you have to make your own, just cut a plastic sheet to the desired area. Cut out a strip of magnet to sit against the perimeter of the duct opening; use a stencil or sketch an outline if necessary. Use the magnetic strip to hold down the plastic sheeting.

Step 4 – Remain Mindful of Vent Cover

Make sure to always remove the vent cover before using the range or oven, even if you don’t intend to run the fan. The cover is not designed to withstand intense heat and may crack or melt. Even if used properly the plastic may become brittle as it ages; replace the cover when it no longer forms a good seal. Magnetized covers can and will be blown off by a strong gust of wind. You may have to occasionally re-attach the cover or even temporarily tape it in place during an intense storm.