Air Tight Damper? Or close to it?

[Scott Townsend]

Do they make an Air Tight Damper?

I'm looking to divert some air form the Existing HVAC Ducts, but do not want to have air from both Directions at the same time. I know they make Dampers that are used for zoning, but they are not air tight. I'm not needing Super Air Tight, but something better then the aluminum Fin in most of the dampers. Looking for 8", 10" and Maybe larger.

Thank you, Scott

[JimL]

Beware! Shutting off too much will damage your system.

[Scott Townsend]

Thank you for your reply. I know I have some hair-brained Ideas, but I'm sure this will work. (-; Most Darwin Award Recipients probably say that too. (-;

My Home has a Zoned HVAC System, so it already has the Zone Dampers to shut off the flow to certain rooms and has the 20+" bypass damper to recirc the excess flow back into the unit.

I'd like to be able to use the Existing Duct Work to be able to Suck air out of the rooms and into the Attic. Similar to the Whole House Fan Concept. Though I want to be able to use my existing duct work. Stick in a Wye and a damper and I'm all set. I have all the electronic control for making Sure the HVAC would not come on when the Attic Fan comes on, etc. So that's not an issue.

I'm just looking for a Damper that wont leak the HVAC Air into the Attic and one that one pull Air from the HVAC when the Attic Fan is on.

Thanks, Scott >

[JimL]