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: 2621

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

Ramon Aguirre replied to Tom Conlon's discussion Whole House Fans - Love 'Em or Not?
"Whole house fan basically serves the purpose of exhaust fans. They are more cheaper than air…"
1 hour ago
Brandon Walton commented on Brandon Walton's photo
Thumbnail

2014-07-25 15.17.30

"While performing a QC it is always good to look inside the return.........."
10 hours ago
Brandon Walton posted a photo

2014-07-25 15.17.30

Supposed Sealed Return Chase
10 hours ago
Brandon Walton commented on Diane Chojnowski's group Facebook Pages
10 hours ago
Brandon Walton joined Diane Chojnowski's group
Thumbnail

Facebook Pages

Does your company or organization have a Facebook Page?This group is for pros who have facebook…See More
10 hours ago
Brandon Walton posted a discussion

12 Things Every Home Performance Contractor Should Have on Their Work Truck

Every home is unique and differs from the last. It would be a perfect world (from a project…See More
11 hours ago
Brandon Walton posted a blog post

12 Things Every Home Performance Contractor Should Have on Their Work Truck

Every home is unique and differs from the last. It would be a perfect world (from a project…See More
11 hours ago
Todd Collins replied to Mike Kandel's discussion Our Homes Suck – And That's Why Our Kids Have Sinus Problems
"Richard,   The study you cited states:    "Patrick N. Breysse, a public health…"
yesterday
Don Fitchett shared their blog post on Digg
yesterday
Don Fitchett shared their blog post on StumbleUpon
yesterday
Don Fitchett shared their blog post on Twitter
yesterday
Kurt Albershardt replied to John Shillito's discussion Fixing a water heater?
"2000 ppm CO is not a problem?  Really?  In what universe?"
yesterday

© 2014   Created by Lawrence Berkeley National Laboratory.

Badges  |  Report an Issue  |  Terms of Service