Discussion in 'HVAC' started by harleysilo, Jan 25, 2007.
Are you talking about a furnace or do you also have a gas water heater?
What you do has nothing to do with a return duct. - That is a part of your air handling system. Fresh combustion air supplies are independant of the air handling system.
It is common to duct it directly to a furnace. An alternate is to duct it into a furnaca/utility room that can be isolated from the rest of the home.
air to condition in from outside...
The incoming air could come from the attic or through the attic to a down turn in a soffit, to the return air duct and could be a 3" PVC pipe. Just make sure it has some sort of screen on it to keep sparrows, rodents and insects out.
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