I am building a smaller 2 story home. Upstairs in one bedroom the return air drops into a joist space, then in the next bedroom another cold air drops into the same space. It then goes over a couple spaces via holes in the joists and then down between 2 studs where there is a 3rd return then into the trunk line in the basement.

My concern is will it pull from the top 2 bedrooms?


As with anything air is always going to take the path to least resistance. Return air is often overlooked by installers because it will work with just a big open duct next to the furnace. If the rest of the install is done fairly well, l then a poor job with the return mayl not have a significant negative impact on the house. If the walls are open I'd address it now. I actually spend more time on return air than I do on supply. If you have architectural drawings with a heat loss calculation they will specify the required cfm (cubic feet per minute) of supply and return. Then duct and return cavities should be sized accordingly. A single stud cavity is only good for about 120 ish cfm which may be good for two rooms depending on the rest of the system and the size of the rooms and if the doors are undercut, the list goes on.

This is a forced air system enter image description herewww.hometips.com

And this is how you would add an HRV to a forced air system enter image description herewww.finehomebuilding.com

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.