Which direction is better.
Attic fan blowing down water heater exhuast.
This article describes routing bath exhaust fan duct upwards through an attic or roof space or downwards through a floor or crawl space.
When venting a bathroom exhaust fan make sure to vent the air to the outside rather than into your attic where it can cause mold and mildew to form.
It s vital that an attic is adequately vented to the outside insulated and sealed from the rest of the home for an attic exhaust fan to work properly.
It is sucking air down from the chimney which runs to the top of your water heater and down to the pilot light.
Using a fan to blow hot air out of the attic doesn t address the radiant heat flow from the roof to the attic floor.
The most common problem associated with water heater venting is a condition called backdrafting in which exhaust gases from the water heater fail to exit the home via the vent and instead end up in the house.
Strong attic fans can actually back draft furnaces or water heaters by pulling combustion gases out of their burnersand into the home.
In all cases the ducting needs to conduct the exhaust to the building exterior and needs to terminate in an animal proof vent cover.
Trying to solve the heat gain problem in your attic by using a fan is like lying out at the beach with a fan blowing over you and thinking you re not going to get a sunburn.
This fan ends up pushing the exhaust gases up the vent and if the water heater vent connector is located directly across from where the exhaust gases are directed the exhaust gases from.
My idea is to vent the build up of hot air that has risen to the ceiling in the hotspot rooms into the attic so that air from cooler parts of the house can move in.
If there are not enough soffit gable or ridge vents a powerful attic exhaust fan can pull the air from your home through the ceiling if it is not perfectly sealed off.
First put some weatherstrip on the basement door and maybe a threshold at the bottom.
This will stop the pilot light problem but now you have to allow some make up air to enter your home to supply the suction to the attic fan.
If an attic is not well sealed from the rest of a home an attic exhaust fan will draw cool air air conditioned air up through the attic and exhaust it out of the home.
Much of that heat then conducts downward and finds its way into the house.