Existing Heating Ducts - Replacement

[XP User]

Hi,

I currently have a forced hot air system in my home with a small maze of output & return vents in the basement.

Since the oil heating unit still works (at 80% efficency mind you), when I go to upgrade it I want to add central air as well as replace all the metal ducts with a smaller PVC (2" or so) so that I could put a drop ceiling in the basement. I want to set it up as an entertainment room/area but cannot do so with a 7 1/2 foot ceiling with only 6 foot of clearance in some areas because of the ducts.

What are the drawbacks in using the forced PVC system vs. metal ducts?

[Joseph Meehan]

You are not going to get the volume of air through 2" ducts to do the job. There are some high velocity A/C units for homes with existing hot water heating systems, but they tend to be noisy and they are not intended for heat distribution. I would also guess they are less efficient.

Sizing of ductwork has to be based on the needs of the heating/cooling system, not the convenience of a basement remodel, unless you want an uncomfortable home.