Helpful? 0

Bathroom mechanical venting

We are building a relatively tight house with a balanced Lunos (through the walls) ventilation system. 2 of the bathrooms are on interior walls so they need additional (unbalance) exhaust fan that will be user controlled and turned on whenever needed. This is being vented to the roof. What mechanisms do we use to prevent cold air entering these exhaust ducts? And also, to minimize thermal bridging through the duct penetrations? thank! Daniel

Asked by Daniel Herskowitz
Posted Sat, 01/11/2014 - 14:37


1 Answer

Select your preferred way to display the comments and click "Save settings" to activate your changes.
Helpful? 0

My opinion is that you should try to go through the wall, both to avoid a roof penetration and because there are good quality wall caps with dampers available. If possible slope the duct downward to the exit point.

There isn't much you can do about the thermal bridge issue. The damper at the wall cap keeps cold air from moving in, but it will still be cold inside the duct due to conduction through the damper. Insulate the duct well. That's about all you can do.

Answered by David Meiland
Posted Sat, 01/11/2014 - 15:01

Other Questions in Mechanicals

In General questions | Asked by Jeff Watson | Jul 12, 14
In Energy efficiency and durability | Asked by Lowell Garner | Aug 20, 14
In General questions | Asked by Tommy Detamore | Aug 19, 14
In Energy efficiency and durability | Asked by Chris Jensen | Aug 18, 14
Register for a free account and join the conversation

Get a free account and join the conversation!
Become a GBA PRO!