Replies

1. 
   MartinHolladay | Jun 02, 2009 04:23pm | #1

   Lots of comments are being posted here -- "Passivhaus for Beginners" --

   http://www.greenbuildingadvisor.com/blogs/dept/musings/passivhaus-beginners

    

1. 
   homedesign | Jun 02, 2009 05:31pm | #2

   Martin,

   I think the passivhaus discussion you mentioned is excellent.

   http://www.greenbuildingadvisor.com/blogs/dept/musings/passivhaus-beginners

   Even Katrin Klingenberg (Passive House USA) has commented.

   Katrin quote: "Passive House is a paradigm shift"

   Now if you could convince Dr. Feist and Dr. Lstiburek to comment .. that would be most excellent.

   I think that merely by studying passivhaus concepts we could significantly improve our homes and buildings.

   If we adopted their heroic standards... it would be a homerun.

    

    

2. 
   shelternerd | Jun 29, 2009 01:14am | #3

   John
   We had our energy audit HERS rating done on the house we're wrapping up with the 12" dbl stud walls. Hit 0.36 ACH50 according to the math at the site done on my blackberry calculator. I'll wait for the official report but that is seriously snug. The 110 cfm bath fans were pulling in the low 60's even with 6" hard metal ducting and a 6" passive make up air vent in the laundry. I'll pull all the back draft dampers in the bath fans to let more air in probably and increase the run time on the occupancy sensors. Un-intended consequences again.

   ------------------

   "You cannot work hard enough to make up for a sloppy estimate."

1. 
   homedesign | Jun 29, 2009 02:03am | #4

   Michael...

   that is tight! even Wolgang would be impressed

   How many CFM was that at 50? how many sf was the house?

   Did you sheath the house completely with OSB or Plywood and use open cell foam?

   Did you see Dr Straube's suggestion about OSB with peel and stick at the joints?

   http://www.greenbuildingadvisor.com/blogs/dept/building-science/how-air-affects-house-part-1

   JB

    

    

1. 
   shelternerd | Jun 29, 2009 02:59am | #5

   Yeah, I saw Straub's advice, but I'm still not sold on the peel and stick, I like a slip sheet to allow the building to rack as it settles. So we're going with Tyvek wrinkle wrap taped to the windows with the FEmA header wrap detail and the NAHB sill-seal-plus-panel-adhesive to keep bugs from tunneling between the foundation and the termite shield under the sill plate. (with 8" spray foam in the roof and band joist and spider in the walls.) The thing we are just starting to do is go OVER the wrinkle wrap and tape with an additional layer of 15 lb felt to keep the back of the siding from touching the Tyvek. I got this idea from the Florida approved stucco details but it makes a lot of sense with fiber cement as well as with cedar shingles (and we're about to side a house with poplar bark $iding) cause that gives a real drainage plane to the face of the wrinkle wrap and doesn't really cost all that much considering that I'm doing the not-so-big but not-so-cheap-either kind of housing.Here's an image of the header wrap detail Steve Baczek drew up from the one we fax to our framers for Green Building Advisor. Hard to get those details just right. Also the kick-out and a cool one-page window install detail we've been working on for GBA. See you in Westford this August? Don't make me come to Texas!------------------

   "You cannot work hard enough to make up for a sloppy estimate."