I have flexible AC ducting that lays across my attic. I need to know if putting fiberglass insulation around and over the ducts will increase the cooling efficiency.

Will putting insulation around the ducts retain attic heat to the ducts or dissipate the heat.

This question has been plaguing me for a long time.

It will slow the migration of the cooling out of the ducts and slow the heat from the attic from penetrating the duct. This is for both winter and summer use

It is a good idea to do this for both a/c and heat purposes