If you have gas appliances, backdrafting may be a problem.
Also, it will not cause backdrafting of gas appliances.
One forum member advised joining the pipes with a "T" and then relying on the dampers within the vent fans to prevent backdrafting
. That's wrong.
* Be aware that in a tightly sealed home, running a powerful exhaust fan (to vent CO from a furnace or water heater) can trigger "backdrafting
." That is, exhaust air will be pulled down your chimney instead of venting to the outside.
Have your appliances inspected by a heating contractor to ensure they're burning clean and not backdrafting
into your home.
"If you have moisture on your windows, the first thing to check for is backdrafting
in the furnace and water heater flues."
Ask a heating service technician to conduct a complete backdrafting
test at your annual heating equipment checkup.
This phenomenon is called backdrafting
. Test your water heater for backdrafting
(it's the most likely candidate) by closing all your doors and windows and running hot water until the water heater comes on.
Vents and chimneys normally carry it outdoors along with other exhaust gases, but problems such as bad drafts, leaky flues, poorly adjusted burners, backdrafting
and smoldering fires either produce carbon monoxide or allow it to enter your home.
This was a good example of "backdrafting
," a reversal of the normal airflow in a chimney.
(I know this sounds complicated, but it's often required in homes with new furnaces to solve the backdrafting
problem.) Most of the newer prefabricated metal fireplaces already have their own outside air supply ducts.
It ensures that your home won't become depressurized, which leads to backdrafting