Inspected a townhouse with a laundry room that has an exhaust fan and also has the gas water heater and gas furnace in the same room. There appears to be sufficient combustion air (through vent to crawl space) and draft air (through vent to attic).
My question is…
doesn’t the running of the exhaust fan while the water heater and/or furnace are operating (burning) cause a potential backdraft situation that could pull combustion air into the laundry room and potentially into the rest of the home?
Or is this not a problem because of the combination of:
- the combustion and draft vents
- draft diverter (water heater) and draft hood (furnace)
- the force of hot air rising
- the relatively weak overhead exhaust fan.
I can see it either way…
Any input would be appreciated…