A noisy forced air furnace can be quite annoying, and installing a new one may not solve the problem. The following tips can help ensure your new furnace is much quieter.
Some movement is normal for any furnace. Small vibrations can lead to noises like rattling and louder than expected humming. These vibrations are caused by the movement of the blower motor and fan assembly. If you find these noises problematic, possibly due to the location of the furnace, there is a way to lessen the vibration.
Anti-vibration pads are best installed at the same time as the furnace. A pad is placed beneath the entire furnace to absorb the small vibrations that affect the housing and lead to rattling. Your installer may also recommend putting a pad beneath the blower assembly itself so that its vibrations are less likely to cause rattling in the housing and other furnace components.
No forced air furnace is completely silent. There will always be a low hum when the blower is running. If your furnace is located near the main living spaces of your home, this hum may be a nuisance. Generally, furnaces tucked away in basements or highly insulated attics don't produce a hum at an annoying level due to their out-of-the-way location.
Improving the insulation around the furnace location is the best way to minimize noise. Most furnaces are installed in a closet or alcove with a door. You can install blown-in insulation into the walls around the furnace. An insulated door can also help. There is also the option of paneling the furnace closet with soundproof panels. This work is easiest to do when there is no furnace in the room, so plan to soundproof at the time of a new furnace installation.
Vent Inspections and Upgrades
Often, the noises that bother you aren't a direct result of the furnace, but instead come from the duct system that feeds into and out of the furnace. During installation, request that your installer perform a quick duct inspection to make sure that all the ducts and their connections are secure. Any loose ductwork can be tightened up.
Another cause of duct noises is insufficient air returns. The returns are larger wall vents that pull in air from throughout your home to recirculate it through the furnace. Many homes only have one return, which means the bulk of the air moves through one duct. The force of this movement can lead to duct noises. Consider having additional returns installed along with your furnace to help minimize duct noises.
Contact a furnace installation service for more tips.