Any time you penetrate the envelope of a home you allow outside air to enter. This applies to all bath and kitchen exhaust fans. A big trend in kitchen re-modeling is to install commercial grade appliances and fans. Some of these exhaust fans require an 8″ or 10″ duct. This can create numerous comfort problems ranging from noise, negative pressure issues and cold air drafts.
Fortunately, most homes don’t have these oversized fans. However, in extreme cold conditions or very windy days, you can probably feel cold air coming from your bath fans. Even though all exhaust fans have plastic backdraft dampers, they are no match for mother nature. If this problem is too annoying or uncomfortable we can usually fix it. If there is access to the fan’s duct work we can install special in-line butterfly dampers. These dampers have an airtight seal and will only open when the fan is activated.