Wood burning fireplace on 13 year old home in Wisconsin. Exterior wall with cantilevered chase. During blower door test I found noticeable air leakage to the inside from above the metal firebox. Would naturally suspect air leakage from the top and back of the chase. However, there are 2 air intakes on the chase - one is for outside air to the firebox as expected. The other one seems to be just an open vent to the chase. Outside air was freely entering the 2nd vent and into the home while building was depressurized.

Anyone know what this vent is for, and does it need to be there?

I don't have a picture, but the two exterior vents were side by side. Sorry too that I don't know the make of the fireplace. They have no complaints with the fireplace area, but I'd like to know.




Views: 1601

Replies to This Discussion

I imagine is pretty hard to tell much without the brand and its installation instructions to know what was required for that particulare fireplace model; not all fireplaces are built nor installed the same. It'll be interested to know how well sealed and insulated were the cantilever and chase before installing the firebox.

Does this home has a second direct vent fireplace between the 2 side windows? 

That is correct Armando.

I'm sure we won't be doing anything intrusive with regard to the chase, but I'd like to know if we could seal off the vent, as that was certainly a pathway for outside air to enter into the home.

Yes. Its correct.

John:  The chase is unlikely to have been treated as "conditioned" space by the builder.  If it is not air sealed it performs basically like a small garage with a fireplace instead of a car in it. 

Current code requires an air barrier in the fireplace chase, but I have never succeeded in retrofitting a chase like the one shown in your picture.


Home Energy Pros

Home Energy Pros was founded by the developers of Home Energy Saver Pro (sponsored by the U.S. Department of Energy,) and brought to you in partnership with Home Energy magazine.  Home Energy Pros is sponsored by the Better Buildings Residential Network.

Latest Activity

SmithWatson commented on SmithWatson's blog post Top 6 Energy Efficient Brands for Gas Furnace and Boiler
"Thank you for your valuable comment Gary.Yes, the product AFUE rating and other numbers are from…"
4 hours ago
Eric Kjelshus replied to Barbara Smith's discussion Eliminating Standing Pilot Light Furnaces
"Biggest pro is to keep the clay or brick or high mass chimney warm  with the 4-8" flame.…"
10 hours ago
Profile IconScott Bloedorn, Matt Macfadden, Lauren Asplen and 1 more joined Home Energy Pros
15 hours ago
Tim Wulling joined David Eggleton's group

1000 Home Challenge

Linda Wigington distinguished between deep retrofits & deep energy reductions, thus expanding…See More
17 hours ago
Gabrielle Rossetti's event was featured

Online Course: ASHRAE 62.2 Ventilation for Single-Family Dwellings at Online - At Your Own Pace

October 15, 2015 at 6pm to November 27, 2015 at 7pm
18 hours ago
Tom White posted videos
18 hours ago
Diane Chojnowski replied to Diane Chojnowski's discussion Solar Decathlon 2015
"Great photos Steven! Thanks for sharing."
20 hours ago
Steven Lefler replied to Diane Chojnowski's discussion Solar Decathlon 2015
20 hours ago

© 2015   Created by Lawrence Berkeley National Laboratory.

Badges  |  Report an Issue  |  Terms of Service