Comments on: How Much Insulation Do You Need in a Passive House?

By: David Eakin

David Eakin — Thu, 18 Aug 2016 02:34:23 +0000

Thor – I would recommend
Thor – I would recommend going to John’s blog space as he has the recommended items (from a University of Pittsburgh study) to measure. The difficulty is that there are no inexpensive, accurate, integrated measuring devices presently for most of those items. Even commonly-available CO meters fall short of recommended safety rules. As far as reducing humidity w/o AC, Matt Risinger (Austin, TX; YouTube channel) often uses ventilating dehumidifiers – and sometimes stand-alone dehumidifiers – in addition to any heating/cooling systems in his location. I believe that a well-known commenter from Ohio is also recommending them for his clients too.

By: John Nicholas

John Nicholas — Wed, 17 Aug 2016 22:11:20 +0000

CZ 4, My location, has a
CZ 4, My location, has a summer design condition of 97°F and 72% RH; Seattle CZ 4 Marine, is 86° F and 66% RH. I would look at a whole house dehumidifier of some type, if you don't want to use a forced air AC. Your area does need dehumidification.

By: Thor Skov

Thor Skov — Wed, 17 Aug 2016 21:37:18 +0000

David,
David, I am building a home in Seattle and I have a couple of questions. How would you take real time measurements of indoor air quality and what would you measure? Also, is there another way to control humidity besides A/C? Thanks.

By: Kris

Kris — Tue, 19 Jul 2016 18:08:24 +0000

With the amount of mobility
With the amount of mobility in the workforce I suspect average homeowner views the single-family dwelling as an intermediate-term investment that is expected to deliver a modest return when they move in 5-7 years. I suspect a majority of code-built tract houses will make it that far without a problem.

By: Stan Rusek, PE

Stan Rusek, PE — Tue, 19 Jul 2016 15:49:28 +0000

Hi. Great article. What is
Hi. Great article. What is your opinion of using vip, vacuum insulation panels, for these homes? My opinions follow. Current SOA of vips to me is poor in that they will always leak out to R/in of 4 to 8. The vacuum enclosure bags are permeable and air will slowly leak in. They remind me of potato chip bags! They are fragile and they are expensive go figure. But thermal resistivity though fleeting can be very high, 50 R/in for current fumed silica vip. Now for the plug. I have a better idea. I am the inventor of the AURA stainless steel foil vip superinsulation panel that OC produced in the mid-1990's for about 5 years, and no longer available. AURA products were sold to Whirlpool and others for super efficient refrig appliances at around $4 per square foot at 0.75" thick. The life expectancy of AURA is incredible since they are hermetic in nature with R/in performance of 75 to 100. Net effective R values at 1 inch range between 45 and 60 including the thermal bridging of the thin 304L stainless foil. I have recent test data for panels over 15 years old that supports the fact that center R values are as good as the day they were made. I am thinking of building a plant to make them again. Prototypes are available for thermal testing and the like if one so desires. My current focus is that I work with clients in the very high and very low (cryogenic) temperature ranges where my rugged new hermetic Century panel makes the most sense. But building applications would benefit greatly, especially these special homes, my opinion. The new Century panel would not be cheap yet but could come down to around $4 per square foot at R 60 effective resistance. So there I put my plug in for Century as an insulation candidate! My architect daughter Samantha (PH qualified) in Austin can't wait until Century is available for her designs there. I have been working on improvements to the old AURA design for the last 10 years and I am ready to rock and roll. Just need an angel investor, some ground, some good labor, and it would be ready to produce in 18 months... I am also getting some interest from OC (Achilles) on same subject so maybe they are ready to rock and roll on this too! I am currently the R&D Director at Quietflex Daikin here in Houston as well as consultant for my company Century Super Insulation, LLC.

By: David Eakin

David Eakin — Sun, 17 Jul 2016 23:12:42 +0000

John – I mostly agree (except
John – I mostly agree (except about that “They are doing the best they can.” bit.) Even “built to code” is better today than in the past. The main frustration I have is that the prevailing attitude (exclusive to residences – doesn’t apply to commercial buildings, cars/trucks or any other manufactured goods) is that houses should last forever, that “old is good because it has ‘character'”, and that real estate increases in value over time. If we (as a society) buy into this, then these “forever” houses should be constructed with the best industry practices of the day instead of the “Meh, it’s good enough.” practices most builders adopt. It is how we have our current dilemma in existing housing stock. Conversely, if we do not buy into that – then every 50 years each residence needs to either be re-constructed to meet the “code” of that day or be deconstructed and recycled.

By: John Nicholas

John Nicholas — Sun, 17 Jul 2016 00:05:04 +0000

David, Just like a code,
David, Just like a code, which is the poorest house you can legally build; Energy Star is a voluntary program that has a minimum. A builder can build to the minimum or build to exceed the minimum. Our local Habitat for Humanity builds a 3 bedroom Energy Star home. This home has to have a HERS Index of 78 or less and meet all the water management and durability requirements of ES. Typically these home score 72 – 69 depended on how much they exceed the blower door test, which effects duct leakage. Until last Wednesday when I presented the Certificate to their newest homeowner with a HERS Index of 61. Still Energy Star certified.

Want to build to the voluntary program of Zero Energy Ready, you have to build to Energy Star first.

Want to build to the voluntary program of Passive House, certified by PHIUS +, you have to build to Energy Star first.

Is a builder, that builds to meet and exceed the local market with a minimal Energy Star Home, a bad builder because there is no Energy Code that requires insulation in any house? Is the same builder in this market that only insulates attics to R-25 and then says it is the level all builders build to a good or bad builder.

No they are doing the best they can. The one is pushing the bar in his market.

By: David Eakin

David Eakin — Sat, 16 Jul 2016 19:25:38 +0000

John – the recommendations
John – the recommendations (prescribed R value, etc.) in the Energy Star program are driven by a balance of current energy prices vs building prices. That is why they have changed over time as energy costs have gradually risen and building costs (at least for framing and insulation) have flat-lined. Is it better than code? Absolutely! Is it best industry practice? No (what’s that Passive House air infiltration and insulation requirement at your climate zone again?). Can it change over time due to energy/building cost fluctuation or political pressure? You bet. Passive House standards will need to change to accommodate climates other than Germany, but not the costs nor political whims.

By: John Nicholas

John Nicholas — Sat, 16 Jul 2016 07:31:00 +0000

David, Energy Star is not
David, Energy Star is not about costs. It is about doing things right, following the checklists. It is about checking your work, the checklists. Checking someone elses work, the Blower Door and Duct testing. It is about durability, with the water management details. I am in CZ 4 and find that 5 ACH at 50, R-13 walls, R-38 attic more about end use energy in BTU's. I've seen the same house built on our local investor owned utility and a mile down the road on the REC. Totally different costs, but 1 HERS point lower because of the Blower Door on the house with the higher $$.

By: Bill Swanson

Bill Swanson — Fri, 15 Jul 2016 21:45:56 +0000

I’ve been trying to think of
I’ve been trying to think of a low labor roof with a high R-value. I like the idea of SIP’s but they peak out at R-50 with a 12″ thickness. Then I found insulated standing seam roof panels that are finished surfaces on 2 sides. A 6″ thick panel is R-48.

Has anyone ever combined the two? SIP panel on the bottom, maybe cedar breather between, and an insulated standing seam panel on top?

Or I could just stick with the affordable option of very thick cellulose.