Bathroom exhaust fans allow the warm, moist air to be exhausted out of the bathroom to the outside of the building. Doing this allows the dry air from the rest of the house to fill the space. To function properly, the bathroom exhaust system must be sized correctly for the bathroom. If it is sized too small, it won't be able to keep up and exhaust all the warm, moist air. If it is sized too large, it will waste energy by exhausting too much warm air outside. It is fairly easy to design a bathroom exhaust system.
Instructions
1. Measure the length and width of the bathroom in which you need to install the exhaust fan in. Calculate the square footage by multiplying the length and width together.
2. Measure the height of the ceiling. Calculate the of the room by multiplying the square footage by the height of the room. If your room is 70 square feet and the ceiling is 8 feet, the room is 560 cubic feet.
3. Calculate the amount of cubic feet the fan has to move in an hour. Bathrooms need eight air changes per hour. To calculate this figure, multiply the cubic footage of the room by eight.
4. Divide the cubic feet of air per hour figure by 60 to calculate CFM (cubic feet per minute). That gives you the size of the exhaust fan you need. Round up to the next size of fan available.
Tags: cubic feet, bathroom exhaust system, cubic footage, cubic footage room, exhaust system, footage room