https://www.energyvanguard.com/blog/keep-out-one-place-never-to-put-hvac-system-ducts/ Building science knowledge, HVAC design, & fun Wed, 09 Jun 2021 13:50:33 +0000 hourly 1 https://wordpress.org/?v=6.6.2 https://www.energyvanguard.com/blog/keep-out-one-place-never-to-put-hvac-system-ducts/#comment-1440 Sat, 16 Apr 2011 01:13:07 +0000 http://energyvanguard.flywheelsites.com/?blog_post=keep-out-one-place-never-to-put-hvac-system-ducts#comment-1440 Jamie:
Jamie: Glad you liked the article. We have to keep plugging away at this, and eventually the tide will turn. There are a few good, conscientious HVAC contractors out there already, so we need to identify them and support them as much as possible. As we keep hammering away at these ideas and showing people the results, things will change. 
 
David & Dave: Yep. That paper’s a great resource. I’m going to dedicate a post to it next week here in the blog and have been putting it out on Twitter and Facebook today. Thanks, Dave!

]]> https://www.energyvanguard.com/blog/keep-out-one-place-never-to-put-hvac-system-ducts/#comment-1439 Fri, 15 Apr 2011 23:51:57 +0000 http://energyvanguard.flywheelsites.com/?blog_post=keep-out-one-place-never-to-put-hvac-system-ducts#comment-1439 David: Glad you found the
David: Glad you found the paper useful. We tried to present the info in an understandable way. Please spread it around… we shall overcome!

]]> https://www.energyvanguard.com/blog/keep-out-one-place-never-to-put-hvac-system-ducts/#comment-1438 Fri, 15 Apr 2011 23:46:19 +0000 http://energyvanguard.flywheelsites.com/?blog_post=keep-out-one-place-never-to-put-hvac-system-ducts#comment-1438 Allison, you know me well! In
Allison, you know me well! In fact, I tell builders and designers that putting HVAC/ducts inside the conditioned space is usually the single most important design decision they can make from an energy performance perspective. Now with the NREL paper, I can show them the data in a concise presentation. Thanks Dave!

]]> https://www.energyvanguard.com/blog/keep-out-one-place-never-to-put-hvac-system-ducts/#comment-1437 Fri, 15 Apr 2011 23:26:25 +0000 http://energyvanguard.flywheelsites.com/?blog_post=keep-out-one-place-never-to-put-hvac-system-ducts#comment-1437 Thanks Allison for the great
Thanks Allison for the great article. I couldn’t agree more and I know your friend Ken Fonorow would agree too!!  
 
Thanks to EVER, I am slowly moving people in this area to see the great value in having a properly designed system. Thanks needs to go to Chris and David Butler too for all the great information and mentoring he has done!  
 
The fact that the most important component of the ‘system’ that controls comfort, durability, energy efficiency and health is just thrown together and treated like a side-thought is a sad reality that must change. I hope, and believe, we are on our way toward better building practices through design and then the most important part of all – testing and verification!!

]]> https://www.energyvanguard.com/blog/keep-out-one-place-never-to-put-hvac-system-ducts/#comment-1436 Fri, 15 Apr 2011 23:20:16 +0000 http://energyvanguard.flywheelsites.com/?blog_post=keep-out-one-place-never-to-put-hvac-system-ducts#comment-1436 David:
David: Since I know you, I know that when you say, ‘Ideally, attic ducts should be supported just above insulation,’ you really meant, ‘Ideally, ducts should be inside the building envelope, but if they’re going in the attic despite research like the paper that Dave Roberts wrote, the best place to put them is just above the insulation.’ Right? 
 
Dan: Another great point, literally! (Actually, many of them.)

]]> https://www.energyvanguard.com/blog/keep-out-one-place-never-to-put-hvac-system-ducts/#comment-1435 Fri, 15 Apr 2011 23:03:29 +0000 http://energyvanguard.flywheelsites.com/?blog_post=keep-out-one-place-never-to-put-hvac-system-ducts#comment-1435 Yeah, and if the duct is
Yeah, and if the duct is against the roof deck,or even the vent chutes, they are likely to get punctured with roofing nails. Insulation crammed around them makes it even more likely when sheetrock is installed & compresses the whole mess!

]]> https://www.energyvanguard.com/blog/keep-out-one-place-never-to-put-hvac-system-ducts/#comment-1434 Fri, 15 Apr 2011 22:23:26 +0000 http://energyvanguard.flywheelsites.com/?blog_post=keep-out-one-place-never-to-put-hvac-system-ducts#comment-1434 Similarly, burying ducts in
Similarly, burying ducts in the ceiling insulation is stupid. Fortunately, many jurisdictions don’t allow this practice, requiring ducts to be supported above the insulation.  
 
Ideally, attic ducts should be supported just above insulation. However, some contractors make life easier by using an upflow air handler, with ducts hung from rafters at hottest point. Go figure.

]]> https://www.energyvanguard.com/blog/keep-out-one-place-never-to-put-hvac-system-ducts/#comment-1433 Fri, 15 Apr 2011 19:29:01 +0000 http://energyvanguard.flywheelsites.com/?blog_post=keep-out-one-place-never-to-put-hvac-system-ducts#comment-1433 George:
George: Great point. Ducts against the roof deck cause problems even when there’s no air being forced through them intentionally.

]]> https://www.energyvanguard.com/blog/keep-out-one-place-never-to-put-hvac-system-ducts/#comment-1432 Fri, 15 Apr 2011 18:52:44 +0000 http://energyvanguard.flywheelsites.com/?blog_post=keep-out-one-place-never-to-put-hvac-system-ducts#comment-1432 Don’t forget exhaust fan
Don’t forget exhaust fan ducts on the roof deck. I use data loggers and the thermal syphoning from a cold roof deck will make the bathroom seem like an outhouse. I logged one system where four 6″ ducts in a vaulted ceiling backfilled the whole HVAC system with 44F air ( it was 30F outside) in about 10 minutes. 
 

]]> https://www.energyvanguard.com/blog/keep-out-one-place-never-to-put-hvac-system-ducts/#comment-1431 Fri, 15 Apr 2011 17:20:46 +0000 http://energyvanguard.flywheelsites.com/?blog_post=keep-out-one-place-never-to-put-hvac-system-ducts#comment-1431 Dave: You
Dave: You’re absolutely right. An attic is no place for ducts. And thanks for the article! (For anyone who doesn’t want to cut and paste, you can download Dave’s article about ducts in attics here.)  
 
You’re also absolutely right about integrated design, and…ahem…we do that. Our architect has been doing a lot of HVAC design over the past year and now really understands how to design a house in a way that accommodates a high performance HVAC system. I put a little note at the end of the article about that with links to our pages for those services.

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