What happens if I have a combustion appliance operating with my Humidex?
Usually the control knob is set at maximum year round unless a combustion appliance (oil furnace, gas/wood stove, fireplace, etc.) is present in the dwelling. With the presence of appliances evacuating air outside the building envelope (such as a Humidex, range hood, bathroom fan, dryer, etc.), a negative pressure could be created inside the building. As the pressure inside the building gets lower than the barometric pressure outside, the smoke and gases from any combustion appliance (oil furnace, gas/wood stove, fireplace, etc.) may be forced into the building rather than go out the chimney. The problem occurs most often in air tight buildings with low efficiency chimney or smoke exhaust systems.
