[GSBN] Can bale buildings be air tight?

[Derek Stearns Roff]

Swiss architect Werner Schmidt (is he on this list?) says that 90% of the air movement needed for ventilation in a standard home is to clear out the toxins released by conventional building materials and furnishings, while only 10% is related to purely people needs.  As Tony says, the architect and builders have no influence on how the occupants furnish and use the space, so indoor air quality ends up being a bit of a question mark.  I suspect that we will see more affordable measuring and monitoring of more indoor air pollutants in the coming years.

In the meantime, well-designed, intentional ventilation ought to be substantially better for the health of both the humans and the structure, compared to a similar airflow rating in a leaky house.  In other words, it's better to build to a .88 ACH50 standard, and increase ventilation airflow, than to have the same air flow poorly distributed by building mistakes.  The articles that I read suggest that bedrooms, where occupants spend a large number of hours, are often under ventilated.  Bathrooms, which need a lot of airflow, often have holes behind the tub and around the plumbing, which provide a path to move lots of moisture into the walls.

I recently read an article, that explained that the standard, UL-listed carbon monoxide detectors are designed to trigger the alarm only at CO levels significantly above the health-risk level of 60 parts per million.  The reason given, is that sounding the alarm at 60 ppm would cause too many "nuisance alarms".  Some health authorities assert that the chronic exposure risk level should be 15 ppm for CO.  Standard CO meters are useless for checking these levels.

I have too parents with respiratory issues, and both live in houses with forced air, natural gas furnaces.  I had installed CO alarms for both of them, so I was very disappointed to learn that these meters don't provide the protection that I had supposed.  I bought a more sensitive CO meter and alarm, and I was pleased to find that both houses have show a CO rating of 0 ppm.  However, so far, I have tested three friend's homes that showed CO levels over 15 ppm; two when running their "sealed" wood stoves, and one home with a gas furnace.

There are plenty of other indoor air pollutants that I would like to be able to monitor, but so far as I am aware, the cost of meters is prohibitive for an amateur like myself.

Derek

On Mar 12, 2013, at 8:49 PM, <ejgeorge at riseup.net<mailto:ejgeorge at riseup.net>>
 <ejgeorge at riseup.net<mailto:ejgeorge at riseup.net>> wrote:

Are you suggesting that the true rationale behind Passivhaus's .60 ACH50 number is that Wolfgang Feist is a Jose Theodore Fan? ;)

With regard to showing where infiltration occurs, the link below is for Jacob Deva Rascusin's Energy Performance for Straw Bale Buildings paper, including thermal imaging on 7 bale buildings in the Northeast US.
Infrared pictures begin on page 40 and a summary of air leakage points (& related moisture issues) is on pages 22-23. There's also some suggestions for construction techniques and detailing in the conclusion section.

www.newframeworks.com/wp-content/uploads/2011/12/Research-Paper-2011_Final_Complete.pdf<http://www.newframeworks.com/wp-content/uploads/2011/12/Research-Paper-2011_Final_Complete.pdf>

cheers!

ej


Quoting Anthony Novelli <anthony.novelli at gmail.com>:

Just a comment and a correction (sic)....

Comment: Kudos for such great strides in achieving these numbers, and thanks EJ for compiling the data. I always have running questions in my mind about the quest for air-tightness, with off-gassing and such. Perhaps less need for air-change systems if this quest is partnered with close attention to materials in construction, though post-CofO purchasing could load any tight building with noxious vapors it seems.

It also seems useful to show where infiltration occurs, and perhaps adapt systems for the "point loads" of moisture to occur at those points?

Correction: I believe the .88 refers to Patrick Kane, in this wondrous season ;) - at least from my Windy City upbringing!

best to you all,
Tony

Chris wrote:

Hi ej,

Our last test on the house was 0.88 (for hockey fans among you, you may
notice that our two scores are the jersey numbers of Wayne Gretzky and
Eric Lindros... coincidence?).

Anthony Novelli
Assistant Director
Development Center for
Appropriate Technology - California Office
2101 Wellmar Dr. Ukiah, CA 95482
(520) 360-8858 o www.dcat.net
anthony.novelli at gmail.com





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Derek Roff
derek at unm.edu<mailto:derek at unm.edu>


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