No doubt a typical single family home isn't realizing 2500 Pa wind-induced pressures....unless the breeze in question happens to have a first name (e.g., Andrew, Hugo, etc).
But 50 Pa pressures? You bet. I have a buddy that…"
"This conversation is great. Seems we are considering attic ventilation as the passive result of isolated-attic stack action.
I'm becoming more and more of the opinion that wind effect likely has a much greater impact on issues of air…"
"Good discussion going here....great forum for this type of more "global" chatter.
Jon, to your website idea. My trepidation here is that a little bit of knowledge can be a dangerous thing. The tightening-up of a building…"
"Hi Grant. This equation should be fine, as a CFM of outside air costs the same to heat/cool regardless of building type. However, I'd recommend considering the cooling costs (sensible + latent) of the associated air leakage as well. Depending…"
"I've been on both sides of the fence here. Have I run blower door tests during audits on simple houses where I already knew what I was looking for? Absolutely. If you are called out by a customer in a market-rate setting and…"
"Thanks for the thoughts, Bud.
We all likely have an opinion of the USGBC. I sat a few weeks ago in on a discussion with David Gottfriend, one of the original founders of USGBC. A (loose) quote of his I found to be interesting:
Are you aware of any efforts made at databasing a large collection of air leakage test results, either by blower door testing or tracer gas testing?
The collective results from years of testing and research might be sorted into bins of comp…"
In a past life, I had always used the following formula for determining potential energy savings for reducing infiltration:
Q= (1.08 * ACH REDUCTION * [volume/60] * 24 * HDD)/ Boiler Efficiency
Q = annual heat loss due to…"
ACHn is irrelevant in a building big enough to have any continuous venilation -- the fans completely change the pressure regime in the building. Many MFBs over three stories (at least in my part of the world) have some sort of…"
I checked with our tech support department and here' what they had to say.
The short answer is no. The wind and stack coefficients that are used in the n-factor calculations are empirically determined from many experiments. There is…"
Hey there, First post on HEP! Exciting times, indeed. A question on ACH and N-factors for multifamily: LBNL’s N-factor converts between pressure induced (i.e.- fan measured) and natural air infiltration rates. The well known N-factor charts max out at 3 story building heights. In the past, I used these N-factors daily when working on single family homes. Any idea if there are equivalent N-factors that can be used (or calculated….) for mid/high rise buildings? I would prefer to deal with a…See More
For too long there has been relatively little EE focus on multifamily, but some new programs have recently started. This group gives us a venue to share our experiences on cost effective audit & retrofit strategies and analysis tool needs.See More
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