Greetings

First of all......

* As we upgrade and build new....

  I think it is time to eliminate atmospherically vented appliances from the breathing zones of our homes

* I realize that the effects of wind and mechanical equipment can and often do overwhelm Stack Effect.

 

My current favorite online resources for visualizing "Stack Effect" are.....

*John Straube's Article

http://www.buildingscience.com/documents/digests/bsd-014-air-flow-c...

 

*John Klote's Article

http://fire.nist.gov/bfrlpubs/fire91/PDF/f91013.pdf

 

*Bud Poll's Worksheet

http://myenergyworkshop.homestead.com/hot-air.html

 

I plan to post some Illustrations and see if you folks agree with my current thinking about the location of Neutral Pressure Planes

Meanwhile...

Does anyone else have suggestions for online links concerning  "Stack Effect"?

Views: 5190

Reply to This

Replies to This Discussion

An important element of the Klote report is that he uses a simplifying formula that only approximates the typical multiple vertical opening model.

"Analytic equations have been developed for the location of the neutral pressure plane for a few simple cases of leakage openings. However, the combinations of leakage openings in building shafts and compartments can be very complex... Analysis is simpler for horizontal openings, because the pressure difference across the opening does not vary with elevation. The analysis of this section is for horizontal openings…Vertical vents can be approximated by horizontal vents when the height of each vent is small compared to the height of the air column."

In a 2500 SF house with 1 ACH50 (about 350 CFM50), the Effective Leakage Area (ELA @ 4 Pa) is about 8 square inches. Since the blower door test is conducted with deliberate leaks sealed, this envelope leakage area is similar to what we might expect from dampered mechanical openings, making both deliberate and accidental leakage areas equally significant.

I'm still not sure what you're trying to accomplish by "controlling" the height of the NPP, especially given that - as you attest - the actual NPP will vary with both wind and mechanical effects.

Here's another link to an old article, CBD-23. Air Leakage in Buildings, from the National Research Council of Canada:

http://archive.nrc-cnrc.gc.ca/eng/ibp/irc/cbd/building-digest-23.html

RSS

Videos

  • Add Videos
  • View All

Twitter

Latest Activity

Amber Vignieri posted a blog post

Relay Network Targets Multifamily Housing Upgrades Nationwide

Affordable apartment buildings are home to more than 10 million American households, making them a…See More
54 minutes ago
Tom White's video was featured

Robby Schwarz on Builder Collaboration

Hear Robby Schwarz, of EnergyLogic discuss the value Owens Corning brings to Thrive Home Builders.
4 hours ago
Profile IconLights N More, John Kamas and Chuck Santeler joined Home Energy Pros
6 hours ago
Crosbey Archery liked Don Hynek's discussion Testing "Magic Pak" units??
6 hours ago
Crosbey Archery joined Norm Bourassa's group
Thumbnail

Multifamily Buildings

For too long there has been relatively little EE focus on multifamily, but some new programs have…See More
6 hours ago
Crosbey Archery liked Crosbey Archery's blog post Energy Tips - Fresh Look at Heating and Cooling the Home
7 hours ago
tedkidd liked Luis Hernandez's discussion Airsealing an old basement ceiling
13 hours ago
Ryan T De La Rosa posted a blog post

The Clean Power Plan and What You Can Do

Last month, Jessica Hardcastle at Environment Leader described an especially non-polarizing…See More
15 hours ago

© 2016   Created by Lawrence Berkeley National Laboratory.   Powered by

Badges  |  Report an Issue  |  Terms of Service