Power-Vent for furnace in shop

Where a power vent in general used is when the 2nd story of a building is occupied thus direct venting would be cost prohibitive as a equipment chase would be required to penetrate the 2nd floor occupied space.

Power vents usually can not be vented lower than 8ft from the ground and most codes call for 10ft. This is to keep combustion by-products above a persons intake air area.

Depends on the type of furnace your installing, determines what type of venting can be used. Some of the newer higher efficieny gas forced air units vent with 2" PVC.

Direct venting is typicaly always the cheapest install.

I'm just giving a overview of typical installationas. You need to consult with the unit mfg to see what are the venting requirements as if you change the vent type then you will void the UL listing and will have servere problems with the unit down the road or right out of the box.

If a salesman is pushing a heating unit lower cost, you can just about bet that install price is greater overall as that unit requires some type of special venting or installation considerations.

T_Bone

You'll need to wire the power vent into the controls of the heating unit. When the thermostat calls for heat, it first turns on the power vent for vent prepurge then allows the heating unit controls to work as normal. Most have a postpurge time delay so the vent again is cleared before unit shut down. It goes thru this sequence on every heating cycle.

Usually type "B" vent, direct venting, is cheaper to install than a power vent.

If you don't know heating controls then you will also need a service tech to inspect the furnace each year.

I would look at the power vent installation instructions before buying as that might help you pick one brand over another or choose direct venting vs power venting.

T_Bone