Comments on: Possible Modifications based on Passive House Standard

By: Grant

Grant — Tue, 23 Sep 2008 22:07:12 +0000

I’m in Alabama and all the suppliers I’m looking at are in Florida.

It’s not a SIP, but the AllWall System uses Cement Fiber Board like an ICF form to pour concrete, and they will train you to make your own forms. The AllWall System seems Owner-Builder friendly.

I vaguely recall one of the Fiberboard SIP manufacturers also offering to allow local manufacturing.

By: chad

chad — Tue, 23 Sep 2008 18:45:37 +0000

Grant – Can you recommend a manufacturer? One within 250 – 500 miles of Philly?

By: Grant

Grant — Tue, 23 Sep 2008 18:37:26 +0000

For future 100K homes take a look at cement fiber board SIPs. While the SIP cost, itself, is higher they are immediately ready for coating on the interior and exterior. Many claim that the “as finished” costs actually end up lower with the CFB SIPs. In fact, an American Clay plaster can be directly applied to the CFB SIP interior with limited prep work. You cut out several steps and have the added benefit of higher thermal mass from the cement fiber board.

By: Kevin D

Kevin D — Thu, 21 Aug 2008 07:37:30 +0000

Edit #3 above: “Natural gas prices will continue to rise quicker that electric prices”

Also, when photovoltaics become cheap enough for this house, they will be unable to assist in reducing your natural gas usage. (The simplest way to a zero energy home is with an all-electric home)

The best way to handle the back-up heat for DHW is probably just one resistance element in the top of the solar preheat tank.

By: Kevin D

Kevin D — Thu, 21 Aug 2008 07:23:08 +0000

I built myself a superinsulated house with radiant floor heat. Since lighting and people essentially heat the house, the floors are rarely warm because the house needs very little heat. Therefore, I feel the extra cost of the boiler system wasn’t worth it.

Also with radiant floors, you may still need to install some sort of A/C, humidifier, and/or HEPA air filtration system. (Do I think you’ll need A/C? yep)

For a house this size and this open, I’d avoid ductwork (as you have) and consider a mini-PTAC (or two) for at least 4 reasons:

1. A/C essentially comes free.
2. Air to air heat pump cycle gives more btus/$ than natural gas or electric resistance. Natural gas prices
3. Ultra low first cost: $439 each.
4. Easy installation (similar to installing a window, in fact, the HVAC sub will never see your jobsite)

There’s a large selection out there, but I like the Amana:
http://tinyurl.com/6ov8e3

By: chad

chad — Tue, 15 Apr 2008 19:48:03 +0000

Charles,

Thanks for correcting my error. I did not mean to specify EPS foam board. I am thinking more of the poly options that will allow R values near R-7.

Also, we did quote the Murus Poly SIPs but can not afford them on our budget.

By: Charles

Charles — Tue, 15 Apr 2008 17:08:28 +0000

Polyurethane SIPs will get you significantly higher R values with only a little bit more money. 4.5″ panel is R26 – 6.5″ panel is R40. Check out Murus in Pennsylvania – http://www.murus.com

1-2″ of EPS will never, ever get you to R14. 1# density EPS (most common) is R3.6 per inch. 2# density is R4.2 per inch.