1. When choosing a new exhaust fan, measure room and match fan size by rating in cubic feet per minute. Once you've selected the appropriate-sized fan, you can begin installation (figure D). 2. For better results, choose a fan rated for a larger room.
3. Consider the fan's sound level; fans are also rated by how noisy they are.
4. Turn off the power at the electrical panel. Remove the nails holding the existing fan in place
5. Disconnect the vent pipe from the old exhaust fan in the attic (figure E).
6. Disconnect the wires on the old exhaust fan from the main electrical feed. The new fan will be connected to that same feed.
7. Always follow manufacturer's installation instructions.
8. After removing the old fan, run the electrical cable into the new housing, making sure to match up each wire: white with white, black with black, green with ground, etc. Twist the wires together and secure with wire nuts.
9. Secure the cables in the fan housing and set in place into ceiling from above.
10. Mount the housing to the framing in the attic using screws (figure F).