Well in the comments dave roberts a senior engineer at the national renewable energy lab nrel wrote about a paper he co authored last year and included a link to it.
Pictures of ways to support ductwork in an attic.
So why put an hvac system up in the attic at all.
Apply a long strip of foil tape along the seam in the insulation.
Most updated central air conditioned homes have a new air conditioner split system meaning the ac is broken up into parts.
Smooth rigid ducts with tape or mastic around all joints will prevent air leakage.
Repeat to insulate the remaining ducts.
I called out the original hvac company and they took a look and said they saw no water.
Flex duct requires the correct support to ensure it does not restrict air as it flows from the air conditioning unit to the registers distributing air throughout.
To install preformed duct insulation start by disconnecting an elbow to expose the end of the duct.
Remember that article i wrote about ducts installed against the roof deck and how i said it was probably the absolute worst single location for installing ducts.
Wrap the insulation around the duct and then pinch the seam closed.
An outdoor unit which houses the fan condenser and compressor and an indoor unit which holds the evaporator and fan.
Recently i had another hvac company come out and put in a new bathroom vent and they told me they believed the duct work was full of water.
Attic hvac systems save space.
Foam tubing or fiberglass will work but it s also possible to buy pre insulated 4 duct.
Well mainly it s a way to save space.
Secure the insulation with short strips of foil tape.
Up against the deck may be the worst place in the attic to.
How to hang flex duct in an attic.