I am not an energy Rater .. I am an architect

I am curious if any "Home Energy Pros" make an effort to locate the Neutral Pressure Plane (NPP) of a house that is being blower door tested?

Views: 2658

Reply to This

Replies to This Discussion

Don, I agree, I agree,

As for actually pointing to an elevation and saying the NPP is about here, somewhere in one of these posts I explained how to do that and it is rather easy.  All that is necessary is a ▲t and a manometer.  From inside and outside temperatures, a stack pressure per foot can be calculated.  Then, by taking a high or low pressure reading (that's where the pressure will be the largest) through the envelope, you have it.  If the front door reading is 2pa and you had calculated a 0.25pa per foot stack pressure, then the NPP is 8' above the penetration at the front door.

If you want to get fancy and you have a good ▲t, you can open a window a measured amount and, just like the "add a hole" process for pressure diagnostics, you can estimate the CFM50.  I keep baiting people with this in hopes that someone will do the math for me :).  My to-do list it too long.

As for the metal capillary tube, you can't get too small as a manometer does require a flow of air.  I would have to ask to be sure.  Just an FYI.

Bud

PS, I have started another thread to get into this issue a bit more: http://homeenergypros.lbl.gov/forum/topics/controlling-passive-air-...

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

Bud Poll replied to Bud Poll's discussion Another benefit from air sealing
"From my work in NY City many years ago, the critters I saw would never have fit through a quarter…"
1 hour ago
Barbara Smith replied to Bud Poll's discussion Another benefit from air sealing
"Eliminating quarter sized holes can impede rats from entering a building, in areas where rats tend…"
2 hours ago
Casey Murphy is now a member of Home Energy Pros
3 hours ago
Walter Ahlgrim replied to James White's discussion What happened to Home Energy Pro's website?
"Try downloading Google Chrome web browser https://www.google.com/chrome/browser/ I had similar…"
19 hours ago
Stacy Hunt posted an event

Building America Webinar: Multifamily Ventilation Strategies and Compartmentalization Requirements at Virtual

September 24, 2014 from 3pm to 4:30pm
The Building America Program is hosting a no-cost, webinar-based training on Multifamily…See More
20 hours ago
Ben Jacobs replied to Bud Poll's discussion Another benefit from air sealing
"This is info I give to clients that I serve. People who live in homes that are not energy efficient…"
22 hours ago
Brennan Less replied to Bud Poll's discussion Another benefit from air sealing
"Thanks Bud. I just feel the need to point out any such issues, because we as a field need to be…"
yesterday
Bud Poll replied to Bud Poll's discussion Another benefit from air sealing
"Hi Brennan, "weak and irrational" is not at all what I was trying to communicate. …"
yesterday

© 2014   Created by Lawrence Berkeley National Laboratory.

Badges  |  Report an Issue  |  Terms of Service