There are many appliances that we vent to the outside of our home - bathroom exhaust fans, dryer vents and range hoods. If you plan to install a high-powered cook top or range during your kitchen remodeling project, then you know that the steam, heat, and odors created on the stovetop must be removed from the air inside your home. When cooking, vapor is released into the room, and much like a bathroom shower, this evaporation can cause a host of problems, such as mold growth or discoloration on wall surfaces. The way to accomplish this extraction is by installing an exhaust fan or overhead hood that will effectively remove condensation from the air.
This chimney hood is one of many styles to choose from.
There are many varieties and sizes of residential exhaust fans available for the home chef. Accurately determining the correct size (CFM) filtration becomes the first step in providing proper ventilation. An oversized unit will generate too large a void of air, forcing the exhaust fan to draw in additional air from around windows and doors, essentially producing a vacuum by the ventilation’s suction, potentially making it necessary to have make-up air provided. Old homes have plenty of leaks to let new air back in - such as drafty windows and uninsulated walls and attics. Newer homes are now built much tighter, and the additional air flow would enter the home thru chimney flues, called backdrafting. Although backdrafting may seem like a minor inconvenience, it has the potential to create dangerous problems to your health and property. Some combustion appliances, for example, contain deadly gases that could be circulated throughout the house. For this reason, the new International Residential Code (IRC) requires adequate provisions be installed to compensate for the exhaust fan and replenish the supply of fresh air into the home.
To assist the fan, a range hood make up air supply vent should be installed. Depending upon the size of your exhaust system, this can be accomplished by simply opening a window nearby; however, this is not a very energy efficient or long-term solution. The best idea is to speak with a knowledgeable HVAC (Heating, Ventilation and Air Condition) professional about installing a make up air vent wired to the exhaust fan. Usually mounted on an opposite wall to effect airflow circulation, products such as the Broan Automatic or Universal make-up air dampers will automatically open and close whenever you operate the fan.
Your electrical contractor can inform you of other ventilation vents and motorized dampers that will provide the needed range hood make up air, as well as the proper size (CFM) exhaust fan for your kitchen. Providing make-up air ventilation will ensure that you can enjoy your new cook-top without reservations or hazardous backdrafts.
For additional resources:
Downlaod our Ventilation Ebook!