Originally Posted by Hwyant
What is proper way to exhaust and intake sir to be installed on a high efficency gas furnace. My daughters was installed with exhast pipe up thru the old vent in a seperate tube to the Ruth. The intake is just set to take air outside the furnace, I thought intake was to come from outside. It's a Lennox Furnace
When in staling a single ex. System combustion air can be taken from a confined space if the proper cu. Feet is in the area 50 cu feet per 1000 btu's. However it is always recommended to use a two pipe system when possible.