insulating basement furnace room with make up air duct make sense?
much of my basement is already finished, but this summer i plan on updating and adding 2″ of xps to the exterior walls and sealing the rim joist with foam. About 3/4 of the basement will be finished, the rest being the utility room with gas furnace and water heater. right next to the furnace is a make up air duct to the outside. I was just thinking to myself, whats the point of air sealing the rim joist when you have a 8″ duct that goes right outside?
I assume this is a typical situation, so is it still worth it to do the insulating ahd air sealing? i can not easily seal of the furnace room from the rest of the basement. Should the make up air duct have some sort of damper in it to keep it from leaking sir when makeup air is not required?