What kind of experience have folks had using blower doors in multifamily buildings?

I hear conflicting info on when and how BDs can be used and useful here.  What are your experiences?  Photos?

Views: 178

Reply to This

Replies to This Discussion

I did a couple of duplex/triplex units last week and was told to test one unit at a time and disregard adjacent units. I wonder if the numbers might be slightly lower if the units were all depressurized at the same time, and I may get a chance to find out.

 

More on this topic: http://www.greenbuildingadvisor.com/blogs/dept/green-communities/bl...

Blower door testing multifamily buildings is just as useful as testing single family homes. The energy savings is usually correspondingly less, since there's typically less exterior exposure. The big difference, of course, is in learning how to deal with leakage to adjacent units. In a row, or townhouse complex, this can be a very minor consideration. Adjacent units would tend, on average, to be pressurized similarly with respect to the outdoors. For accurate testing, we would want to have access to the neighbors units, either to install a blower door in them, and equalize the pressure across any shared walls, or at the very least to open a window/door to treat neighboring units as the outdoors.

 

In larger, multi-floor, buildings, the leakage within the building begins to have a significant impact. If we restrict ourselves to energy savings, and ignore the equally significant indoor air quality concerns, air leakage to the outdoors is no longer the only concern. Depending on a units location within the building, top floor vs. bottom floor etc.., the air leakage due to the stack effect (movement of warm air up the building column) can have major energy savings implications. In a cold climate, it's entirely possible to see units at the top of a tall multifamily building with their windows open. This is typically because the movement of warm air from the lower floors is so significant that the top units are feeling too hot. The net effect of opening windows, naturally, is to draw yet more warm air up, further cooling lower units, causing them to want even more heat. You can see where this is going...

 

The solution, when it comes to air sealing, is to not only isolate leakage to the outdoors, which can be done by neutralizing leakage to adjacent units and floors, but also to learn to isolate leakage to each adjacent unit, hallway, and floor. Not easy once a building becomes occupied.

RSS

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.

Latest Activity

Steven Lewis replied to Christopher Talarico's discussion Heating with Tankless Water Heater & Hydronic Air Handler vs. Gas Furnace
"It looks better on paper than in real life applications.  Both Amana and Lennox came out with…"
16 hours ago
Dennis Heidner replied to Christopher Talarico's discussion Heating with Tankless Water Heater & Hydronic Air Handler vs. Gas Furnace
"Rinnai has application note on how to use their tankless hot water heater with a Rinnai water to…"
yesterday
Hal Skinner replied to Hal Skinner's discussion How much heat energy is lost through the floor of a house?
"I found the buildingscience article interesting.  Interesting that they noted the wet bottom…"
yesterday
Bud Poll replied to Hal Skinner's discussion How much heat energy is lost through the floor of a house?
"With conduction that ends at the bottom of the joists and convection that is naturally suppressed…"
yesterday
Hal Skinner replied to Hal Skinner's discussion How much heat energy is lost through the floor of a house?
"Good morning Bud, Took a quick look at the site and a couple others listed on the Yahoo…"
yesterday
Bud Poll replied to Hal Skinner's discussion How much heat energy is lost through the floor of a house?
"Hi Hal, Search "Basecalc basement heat loss".  From memory Canada (nrcan) has/had a…"
yesterday
Michael Dunseith posted photos
Saturday
Hal Skinner replied to Hal Skinner's discussion How much heat energy is lost through the floor of a house?
"II just remembered seeing a report by a federal adency, many years ago, that basically said …"
Saturday

© 2014   Created by Lawrence Berkeley National Laboratory.

Badges  |  Report an Issue  |  Terms of Service