https://www.energyvanguard.com/blog/testing-for-duct-leakage-in-a-house-with-an-encapsulated-crawl-space/ Building science knowledge, HVAC design, & fun Fri, 08 Jun 2012 21:19:14 +0000 hourly 1 https://wordpress.org/?v=6.6.2 https://www.energyvanguard.com/blog/testing-for-duct-leakage-in-a-house-with-an-encapsulated-crawl-space/#comment-4139 Fri, 08 Jun 2012 21:19:14 +0000 http://energyvanguard.flywheelsites.com/?blog_post=testing-for-duct-leakage-in-a-house-with-an-encapsulated-crawl-space#comment-4139 What we do is ask the builder
What we do is ask the builder to either provide a crawlspace access from inside the house (in closet or under staircase, if possible), so we can open it to connect the crawl to the house when depressurizing, or install a transfer grille behind a bathtub or shower where the subfloor has a large hole for the plumbing drain lines leading into the crawl. The first method is much better than the second, but as long as the hole in the subfloor is big enough to equalize the pressure difference between house and crawl, it shouldn’t make a difference testing the ducts. 
 
Also, if neither of these scenarios is present and you test the ducts without a pathway to the crawl and the duct leakage rate passes your requirements, then the leakage rate should be even less if the crawl were actually connected to the house. So, in that sense you CAN test a house that doesn’t have a connection to the crawl, however if the duct leakage doesn’t pass as-is, then you’ll need to find a way to connect the crawl and re-test to see if it passes under the correct set-up.

]]> https://www.energyvanguard.com/blog/testing-for-duct-leakage-in-a-house-with-an-encapsulated-crawl-space/#comment-4138 Thu, 31 May 2012 20:57:28 +0000 http://energyvanguard.flywheelsites.com/?blog_post=testing-for-duct-leakage-in-a-house-with-an-encapsulated-crawl-space#comment-4138 Amen
Amen

]]> https://www.energyvanguard.com/blog/testing-for-duct-leakage-in-a-house-with-an-encapsulated-crawl-space/#comment-4137 Thu, 31 May 2012 16:59:38 +0000 http://energyvanguard.flywheelsites.com/?blog_post=testing-for-duct-leakage-in-a-house-with-an-encapsulated-crawl-space#comment-4137 We continue to ductblast HVAC
We continue to ductblast HVAC systems but few people perform the more important static pressure testing required to ensure the system is properly designed and installed and delivering the proper airflow. Sealing ducts on an undersized, improperly designed duct system oftentimes creates more issues than it solves. I predict in the next few years we are going to have a record amount of premature compressor and fan failures. In variable speed units that are typically higher SEER rated, the fans just work harder and the watt draw goes through the roof. In Alabama, where I live, code officials do not enforce Manual J,S, and D requirements and many HVAC systems are a joke. However, many are tight though thanks to ductblasters.

]]> https://www.energyvanguard.com/blog/testing-for-duct-leakage-in-a-house-with-an-encapsulated-crawl-space/#comment-4136 Wed, 30 May 2012 23:32:17 +0000 http://energyvanguard.flywheelsites.com/?blog_post=testing-for-duct-leakage-in-a-house-with-an-encapsulated-crawl-space#comment-4136 pj:
pj: Whether or not we should test every house is a different discussion. What I was hoping to see in the comments here were ideas about innovative solutions raters have developed to make sure they test duct systems according to the HERS protocol. Liking rigging up an inexpensive fan to a variac to pressurize the crawl space instead of buying another Blower Door or duct tester. 
 
David B.: Indeed it is. When used for QA/QC purposes, you don’t need to pressurize the crawl space or the house. I’d just do the total leakage test.

]]> https://www.energyvanguard.com/blog/testing-for-duct-leakage-in-a-house-with-an-encapsulated-crawl-space/#comment-4135 Wed, 30 May 2012 23:31:27 +0000 http://energyvanguard.flywheelsites.com/?blog_post=testing-for-duct-leakage-in-a-house-with-an-encapsulated-crawl-space#comment-4135 PJ wrote: 

PJ wrote: 
> By the 6th house, you can predict your test in and test out numbers, why test the next 994?  
 
You’re looking at this from the contractor’s perspective (although in my experience, even the best crews screw up their ducts from time to time). HERS must be viewed from the home buyer’s perspective. S/he has no idea how good your work is, nor does the builder, without testing. In new construction, HERS ratings (and even more so, Energy Star) are more about QA and verification than a score. That’s where the real value is. Otherwise builders can (and do) hang “energy efficient” or “green” shingles on their new homes with nothing to back it up.  
 
It’s really amazing to look back at the progress over the last 6 or 7 years. Competition and awareness resulting from Energy Star has led us to the point that nearly half of all new homes now participate in some sort of 3rd party site verification program.

]]> https://www.energyvanguard.com/blog/testing-for-duct-leakage-in-a-house-with-an-encapsulated-crawl-space/#comment-4134 Wed, 30 May 2012 23:13:08 +0000 http://energyvanguard.flywheelsites.com/?blog_post=testing-for-duct-leakage-in-a-house-with-an-encapsulated-crawl-space#comment-4134 @pj, bad analogy. Like cars,
@pj, bad analogy. Like cars, production builders can participate in RESNET sampling program whereby only a fraction of the houses must be tested.  
 
Aside from HERS testing rules, duct leakage testing is an invaluable QA tool. Mechanical contractors who don’t at least spot check their crews’ work are selling snake oil when they tell builders how tight their ducts are.

]]> https://www.energyvanguard.com/blog/testing-for-duct-leakage-in-a-house-with-an-encapsulated-crawl-space/#comment-4133 Wed, 30 May 2012 22:24:24 +0000 http://energyvanguard.flywheelsites.com/?blog_post=testing-for-duct-leakage-in-a-house-with-an-encapsulated-crawl-space#comment-4133 I guess we should
I guess we should individually test each car for their MPG as well.

]]> https://www.energyvanguard.com/blog/testing-for-duct-leakage-in-a-house-with-an-encapsulated-crawl-space/#comment-4132 Wed, 30 May 2012 20:50:41 +0000 http://energyvanguard.flywheelsites.com/?blog_post=testing-for-duct-leakage-in-a-house-with-an-encapsulated-crawl-space#comment-4132 pj & Paul
pj & Paul: And let’s not forget that even the best workers may not be as good on seis de Maio or 18 March!

]]> https://www.energyvanguard.com/blog/testing-for-duct-leakage-in-a-house-with-an-encapsulated-crawl-space/#comment-4131 Wed, 30 May 2012 20:47:07 +0000 http://energyvanguard.flywheelsites.com/?blog_post=testing-for-duct-leakage-in-a-house-with-an-encapsulated-crawl-space#comment-4131 pj … ya just never know
pj … ya just never know when a new installer is hired or a new sub crew. also, if subs know they will not be tested, all of a sudden the mastic job is not as good, no hard pipe in flex duct connections, exterior penetrations not sealed effectively, no caulk at boots, plenums, electrical outlets … etc …on and on. 
I’d be alot more comfortable if my subs knew they will be tested and with tracer smoke & infrared, we WILL find the guilty party.

]]> https://www.energyvanguard.com/blog/testing-for-duct-leakage-in-a-house-with-an-encapsulated-crawl-space/#comment-4130 Wed, 30 May 2012 20:22:47 +0000 http://energyvanguard.flywheelsites.com/?blog_post=testing-for-duct-leakage-in-a-house-with-an-encapsulated-crawl-space#comment-4130 Allison, 

Allison, 
 
We do agree, and I also agree with your example. 
 
Exactly as you stated, it is about personal feelings, sales, and marketing, but not statistically relevant and costs your first year savings. 
 
By the 6th house, you can predict your test in and test out numbers, why test the next 994?

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