Increasing Supply register size?
I would like to know whether increasing the boot and associated supply-register from a 4x10 to a 6x12 would have any negative effect on my system.
The reason I am considering this is that the old 4x10 boots were not insulted, and collected condensation in a (previously) damp crawl-space. The condensation caused mold and subsequent wood rot of the subfloor around the underside of the boot. The most severly affected wood is around a register where air flow is not vital (it's right next to the front door), and we have to replace a lot of rotten subfloor anyhow. Increasing the opening size would allow us to cut away the moldy and rotten wood.