[Montana_657]

This won't be pretty but it will help.

First you need a caulking gun and some caulk... I like Altex latex...cheap cleans up with water tastes great!!

Pull the air filter. Inside the space you will find two big holes into the attic space with a couple of wires running through them. Caulk everything, sealing all the holes and replace the filter.

Remove the diffusers on the ceiling vents. They snap on, grab the edge and kind of roll them toward the center.

Steal the wifes compact..you need the mirror not the powder If you shine the flash light in one diffuser (louvers removed) you can go to the next diffuer and check the duct with the mirror. Look for collapsed or disconnected ducts.You may need help here or very long arms.

While your looking up in the holes you will probably notice some of the silver duct material is covering the hole, kind of a crescent shaped slice along the edges.This is not good.It means cold air is being pumped into the attic spaces.If you reach up there on the opposite side from the crescent, you can feel that there is a gap in the duct work.

Grab a sharp wife... I mean knife.A steak knife will do. Cut the silver crescent out of the ceiling diffuser houseing. The duct should now fit around the plastic. Save the silver crescent.

Now the fun part....Goop some caulking into your hand and glue the silver bit into the hole on the opposite side of the ceiling diffuser, sealing the duct to the diffuser.There is no easy way to do this ... or keep clean so enjoy.

Now you can feel smug... you are no longer trying to air condition the great out doors.Time for refreshments.