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: 3992

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

Videos

  • Add Videos
  • View All

Twitter

Latest Activity

Steven Lefler posted a status
9 hours ago
Ryan T De La Rosa is now a member of Home Energy Pros
9 hours ago
Chris Dorsi posted a blog post

My Favorite Announcement of the Year

Each year, Habitat X engages in…See More
11 hours ago
R Higgins replied to Energy Wise Solutions's discussion No Utility Homes, Are we ready to start building Homes that are not connected to traditional utilities ?
"First off, check the laws in your area.  Drought prone areas often prohibit on site collection…"
19 hours ago
R Higgins commented on Tom White's video
Thumbnail

Building Science Insights -- To Vent or Not to Vent

"Great lecture, kept thinking, but what about existing buildings.  Too little room at eaves for…"
19 hours ago
Luis Imery added a discussion to the group Job Board
Thumbnail

Hiring: Construction Manager with High Performance Custom Home Experience

POSITION DESCRIPTIONJob Title: Construction ManagerDepartment: Construction –…See More
yesterday
Profile IconLuis Imery and Quinn Korzeniecki joined Diane Chojnowski's group
Thumbnail

Job Board

This group is for posting jobs related to all aspects of the home performance industry including…See More
yesterday
Colin Genge posted an event

Retrotec is attending the NEBB Testing and Balancing (Tab) Certified Professional Review Seminar in Chicago, IL at Hilton Chicago O’Hare Airport

June 6, 2016 at 8am to June 8, 2016 at 5pm
Building owners and tenants are concerned that the environmental performance of buildings must be…See More
yesterday

© 2016   Created by Lawrence Berkeley National Laboratory.   Powered by

Badges  |  Report an Issue  |  Terms of Service