[GSBN] Fwd: Can bale buildings be air tight?- How to ventilate

[Graeme North]

Robert has said that I can forward his post below onto the GSBN network for him - it seems that he can not post for some reason.

I seem to have stirred up a wee storm of hornets.  Sorry.

And my apologies to John, in particular, to rouse him from the end of his comfortable winter hibernation.  (How are you going John, apart from having an annoying antipodean burr under your pelt?)

I will cobble together a longer post when I get a moment to scratch myself.

cheers

Graeme


Begin forwarded message:

> From: Robert Riversong <housewright at ponds-edge.net>
> Subject: Fw: Re: [GSBN] Can bale buildings be air tight?- How to ventilate
> Date: 21 March 2013 6:31:49 AM NZDT
> To: Natural Builders Northeast <nbne at lists.riseup.net>
> Cc: Graeme North <graeme at ecodesign.co.nz>, John Straube <jfstraube at uwaterloo.ca>
> Reply-To: housewright at ponds-edge.net
> 
> I've recently signed up to receive posts to the GSBN list, and find it frustrating that I can't respond to the comments, so I'm forwarding this piece of the thread to NBNE so I can add my own 2¢ (or 2 bits, adjusting for inflation).
> 
>  
> With all due respect for John Straube (whom I have often cited as THE authority on cold climate hygro-thermal issues), I think he (and probably Derek) is missing the point made by Graeme - a point I've been making for years and which I detail in the ten-part essay I wrote for BuildingGreen dot com, which we titled Riversong's Radical Reflections [on shelter], also available at my blog Riversong Housewright.
> 
>  
> I think we would all agree with Straube that "properly designed and constructed buildings with reasonable operation by occupants work fine, and badly designed or constructed buildings badly operated causes problems." - and with Derek that "Creating a healthy house requires knowledge, understanding, and attention to many details."
> 
>  
> But what Graeme seems to be trying to say is that what we now think of as a house has evolved from simple shelter to a highly-engineered machine that requires "operation" by its occupants in order to maintain a comfortable and healthy indoor environment. And the engineering or technophile mindset equates health with lack of disease rather than the holistic and harmonious interaction with our environment which allowed humanity to survive for 2½ million years.
> 
>  
> Evidence of the narrowing of our thinking is demonstrated in the use of the term "indoor environment". The word "environment" derived from the verb environ, meaning surrounding or encircling, and which connoted an embedment in the world around us, but has come to mean something "other" than and outside of ourselves to which we relate (and which we can control or manage).
> 
>  
> That our environment has moved indoors (we moderns spend 90% of our lives indoors) and requires active management is indicative of how far we've digressed or run away from the natural environs which birthed and nurtured us for so many millennia.
> 
>  
> What Graeme calls "chilly bin" houses, I've called the hermetic house, which relies on artificial life-support systems to maintain a livable interior "environment". I agree with him that this is a potentially dangerous development, which undermines resiliency and creates its own "progress traps" (see Ronald Wright's 2004 book and Massey Lecture series A Short History of Progress).
> 
>  
> That we need mechanical ventilation in our homes today is a result of our need for increasing amounts of insulation which is the result of our increasing population and increasing demand for energy, which is in part a result of our ever-growing sense of need for consumption, comfort and control, which is a result of a mindset or cultural paradigm that is based on the myth of progress and a blind faith in technological "solutions" to problems created by the last generation of technological "solutions" (a classic progress trap).
> 
>  
> That we don't have much of a choice today in the necessity of mechanical ventilation in well-insulated homes is evidence of the cul-de-sac that our "progress" has driven us into. The perfect shelter in a very cold environment is the igloo or quinzee (snow shelter). It is built of immediately local materials which return seasonally to the environment with no impact and can be rebuilt in a matter of a few hours, and hence are the most sustainable structures. But they require (as Farley Mowat discovered when he became perhaps the first white man to live with the Inuit after WWII) that one must wear most of one's "shelter" on one's back in the form of equally indigenous and bio-degradable double skins with fur. The Inuit were remarkably capable people to be able to live so well in such an unforgiving climate, but rather than trying to control their environment they learned how to adapt to it.
> 
>  
> We have come to substitute control for adaptation, which was the driving force for biological and cultural evolution for 3.5 billion years on Earth. And we have perennially discovered that we are simply incapable of managing the world as well as Gaia, no matter how clever we believe we are.
> 
>  
> - Robert
> 
> 
> 
> --- On Wed, 3/20/13, John Straube <jfstraube at uwaterloo.ca> wrote:
> 
> From: John Straube <jfstraube at uwaterloo.ca>
> Subject: Re: [GSBN] Can bale buildings be air tight?- How to ventilate
> To: "Global Straw Building Network" <GSBN at sustainablesources.com>
> Date: Wednesday, March 20, 2013, 11:53 AM
> 
> I have kept quiet on this issue for a while partly because I was too busy and because it was really annoying me so I wanted a measured response. Derek as usual does a good job.
> 
> The discussion is disappointing to me as it is covering topics and ground that have long since been investigated, mostly understood and resolved in the research literature.  The research has been used in construction practise in some areas of the world for decades now.
> 
> When I started studying buildings scientifically as a grad student in 1991, I read all kinds of articles from the 70s' and 80's that said things like:
> "You dont want the house too tight or you will kill yourself" or
> "Those tight houses are very unhealthy"  etc etc.
> 
> Such comments are mirrored here 30-40 years later, where it is stated as if, by common sense, airtight buildings are less safe.  Those type of thoughts resulted in research in the 70's by hundreds of researchers (many in Scandinavia and Canada), and the construction of thousands and thousands of airtight homes, some of them very airtight (e.g. Canada built more than 10000 houses of less than 1.5ACH at 50Pa under the R2000 program, so we have a good sample size).
> 
> The claim that "airtightness = unhealthy" is simply not true.  
> 
> Of course the claim "straw buildings rot" and "earthen buildings fail in earthquakes" is also bandied about as a given common sense conclusion by people who have not done the research or learned about the work that has been done to make straw buildings that are quite durable, and earthen buildings that are quite safe in earthquakes.
> The difference between the common sense conclusions and the real world experience and measurement in both the case of airtiightness and natural building materials is the same: properly designed and constructed buildings with reasonable operation by occupants work fine, and badly designed or constructed buildings badly operated causes problems.  Problems like rotting straw, collapsed adobe, and sick people. It is perplexing that there are some people who will take the spoils of research and experience to support wider spread adoption of natural building materials, but spurn the same type of research and experience when it relates to airtightness (or some other approaches).
> 
> I believe there is a clear reason for some of the disdain of airtightness. It is similar to the disdain people have for insulation (like the super insulation values of straw bales).  It depends on where you live.
> In San Diego, or Auckland, or Tolouse, it is easy to dispense with insulation and airtightness and afford the energy required to maintain comfort within bands more narrow than the cave Derek says he does not want to live in (neither do I: I would likely be dead by now if I had to live in a "natural" cave.  But lets say you live in Stockholm, or Ottawa, Sapporo, Denver, or, heaven forbid Edmonton or Fairbanks.  Claims that is is somehow better, more natural, and superior to live with poor airtightness became really ludicrous really quickly once folks could experience what a "tight" 1975 Canadian home delivered.  Customers voted with their feet.  Now standard houses, without regulations requiring this, are approaching 2ACH at 50Pa, because this reduces complaints, solves moisture problems and ensures good air quality.  The same path has been followed in Sweden and Norway.  Passive House is adopting these principles and trying to apply them to the Central European climate.  The same princi
> ples as applied to cold climate housing are now being deployed in less cold, and even somewhat temperature environments  The need is not as obvious, and neither are the benefits is climates like Auckland, or San Francisco.  And the performance targets dont need to be as tight.  But they need to be much better than they are now.  The houses I visited and stayed in during my three visits to New Zealand where  appalling by Swedish or Canadian standards. To claim that airtightness and foam sheathing is the cause of the problem is to ignore all the real reasons: lack of proper design and construction. San Francisco is filled with buildings that are uncomfortable. On my California sabbatical I lived in a rented house in Oakland.  Victoria (my partner, born and raised in Edmonton) and I both declared this the coldest winter either of us had ever experienced in our 40 years, even though the temperature never reached freezing once. It cost me twice as much energy as I was paying for my large
> r house back home in Ontario during the same period.  Was it healthier?  Hell no!  We had mold growing under our futon, air leaked in from the mouldy crawlspace, we had to dust all the time because the leaking air brought in dust (which is a real IAQ issue).
> 
> There is also the assumption that a house that tests leaky provides more fresh air.  This is not true and physics, tests, and measurements have shown this to be not true.  An air leakage tests measures the total number of holes in your house.  however, to have air move across the holes, you need to have a pressure difference.  A house with lots of holes (aka leaky) will provide little exchange of air on a non-windy day when it is 15 C (60F) outside because there is no driving force.  And during a cold (10F) windy night, it lets in lots and lots of outdoor air, none of which helps the indoor air quality.  When researchers MEASURE the indoor air for pollutant tracers like formaldehyde, TOCs, dust, mold, they find that there are many hours at a stretch that have high concentration and many hours at low concentration. In an airtight house with a ventilation system, the pollutant levels never spend a lot of time at the high levels, and consistently operate a steady low levels.  The levels
>   both houses operate at will depend mostly on how many pollutants are in the house, not on wether the house is leaky or airtight with a ventilation system. And of course we learned that you if rely on accidental holes to provide "fresh" air, the outdoor air that leaks in is anything but fresh, as it has been pulled through the unclean able building enclosure, passed over the dead squirrel in the attic, picked up the fumes from the lawnmower gas can in the garage etc.
> 
> 
> Airtightness is not the same as uniform temperature and RH.  Where this leap comes I dont know.  By all means, let the house get to 15C (60F) during cold weather and let it rise to 30 C (86F) in summer. If that makes it feel more natural, makes you feel more alive, in connection with the outdoor world, then by all means operate your house that way.  But when it is freezing outside, 0C/32F, an airtight house will require less energy to maintain at 15 than an air leaky house.  My current house is less than 1 ACH at 50Pa, has walls of R40 and triple glazing, and the living room temperature swings from below 20 early in the morning to above 25 when the fireplace is blazing, and the temperature in the bedroom at the far corner of the house is a few degrees cooler.  There is no connection to airtightness.  If I wanted to have a uniform temperature of 21C, I could easily and, importantly, at low energy cost, achieve this goal.  It is my choice, a choice made possible by good airtightness and g
> ood insulation.  Some of my neighbours live in rural houses built in the 1880-1920's of natural brick, plaster, stone, and wood.  They are slowly renovating or demolishing these houses because they want the choice to control the interior conditions, not usually a fixed 21C, but to some range of their choosing. And they want to do that at as low a cost and energy use as practical.  That is only possible with proper airtightness and insulation.  The only difference is that it takes less airtightness and less insulation in San Diego than Edmonton.  But it still takes some, more than is being provided.
> 
> I hope you will excuse the rant.  I am going outside now to enjoy the beautiful sunny day and -3C spring weather.
> 
> 
> 
> On 2013-03-20, at 12:34 AM, Graeme North <graeme at ecodesign.co.nz>
> wrote:
> 
> > Thanks Derek - I do work on the assumption that waking up alive beats the alternative but yes, I recognise that there are prejudices and suppositions involved there - ones I don't intend to apologise for.   
> > 
> > And indeed there are instances where highly insulated and air-sealed surroundings have killed.  Think of the tragedy when people - often kids -  get trapped inside an old fridge or freezer.  Not quite a house I agree, but some houses seem to be heading in that direction.  The slang term for polystyrene clad houses here is "chilly bin" houses. ("Chilly bins" are those handy portable polystyrene containers we use to keep picnic stuff cold in).  When these houses incorporate air-sealed windows and doors, have very limited air changes, and are full of toxic materials and furnishings, they give a rather unhealthy environment.  
> > I do agree that energy use needs careful attention, very much so, but also our ability to interact with our natural environment needs careful conservation. I for one, do not wish to inhabit some kind  of perfectly controlled machine, one that used to be called a house, that delivers perfectly homogenised living conditions 24 hours a day.   Variation in temperature and humidity is perfectly acceptable within quite a range, as we all know. Moderating the extremes does make for better comfort, and health, and its what we aim for I hope. Some technology can be appropriate here, especially if it is  appropriate technology,  but we do not need every room in an oversized, overstuffed, house to be a consistent 21deg C.   There seems to be a growing fear of the outdoors and all the dangers that lurk therein.  We live on a spaceship called Earth, and not on a rocket to Mars.
> > 
> > Yes I agree that unsafe and unsanitary housing adversely affects far too many people, and certainly contributes to some avoidable illnesses. 
> > How to improve this situation without costing the earth is an interesting topic that exercises many of us, and as Derek says, the solutions will require knowledge, understanding  and attention to details.  Hence the rich value of these discussions, and the value of this network.
> > 
> > But I also think that mental approach has a large part to play. For my money, sustainability is an "attitude" that precedes anything else.  What I don't like is a resource-rich approach that mimics, far too much for my liking, the notion that if something isn't working, then you are not throwing enough technology (read "brute force") at it.  
> > And there is always Jevon's Paradox to come into play, just when you think you are on to something.
> > 
> > Cheers
> > 
> > Graeme   
> > 
> > 
> > 
> > 
> > 
> > 
> > On 16/03/2013, at 3:17 AM, Derek Stearns Roff <derek at unm.edu> wrote:
> > 
> >> I'm in partial agreement with Graeme, and I appreciate his comments.  I'm opposed to waking up dead from any cause, although I admit that this reflects prejudice and supposition in my case, since I have never tried it.  But I think we need to be careful of false dichotomies, spurious connections, and wishful thinking.  
> >> 
> >> I advocate healthy buildings and a healthy world, and I suspect everyone on this list would say the same.  I advocate connection with the natural world, while preferring to sleep in a healthy natural house, rather than spending my life in the much more natural state of our ancestors 100,000 years ago.  I don't have the skills needed to survive as humans did deep in prehistory, nor do I have the community and habitat to support that lifestyle.  Like most of us, I am striving to understand the best balances and combinations between old and new.  
> >> 
> >> I think it is a false dichotomy if we equate tight houses with health risks and leaky houses with health.  How many cases can we document, of people who have woken up dead because the mechanical ventilation system in their tight house failed overnight?  Around here, the people who are killed by their houses each winter live in leaky houses, with bad wood stoves or fossil fuel furnaces.  Most of the people with chronic home-induced health problems don't live in well-designed tight houses, rather they live in average to leaky homes, with compromised heating and coolings systems, mold, toxic materials, and ventilation problems.  Having random leaks does not guarantee good ventilation, nor good indoor air quality.  Neither does having a mechanical ventilation system.  Creating a healthy house requires knowledge, understanding, and attention to many details.  
> >> 
> >> Derek
> >> 
> >> Derek Roff
> >> derek at unm.edu
> >> 
> >> On Mar 14, 2013, at 3:51 PM, Graeme North <graeme at ecodesign.co.nz> wrote:
> >> 
> >>> Well my 2c worth is that in NZ we have a long history of cold damp houses, in a very humid mostly temperate climate.  (As it is at the moment we are in the grip of the worst drought for over 70 years so any hint of damp would be welcome.)
> >>> 
> >>> That aside - the best strategy I have found for drying out damp houses is to use hygroscopic materials in the fabric of the house - and the best and easiest is earthen walls or at least earthen plasters on any suitable substrate such as dry wall.  Of course to help get over cold we insulate and that's where sheep's wool, or strawbale,  or low density earthen materials, come into their own.  Condensation on windows and the accompanying wet window sill syndrome simply vanishes.  Needless to say we don't have several cm of snow lying around but we do get some pretty good frosts.  Then reducing the size of houses and the size of windows in them also helps. Lets face it, oversized badly orientated triple or quadruple glazed self ventilating thermally broken windows are still not nearly as good as a bit of well insulated wall at keeping heat in or out.  
> >>> 
> >>> I suggest that the approach of using more and more of the earth's resources to sort out these building issues  may not be a good primary design strategy, especially when it leads to oversize buildings, with oversized windows needing mechanical ventilation systems etc., -  mechanical systems that are only as good as their energy supply.  I don't want to wake up dead of asphyxiation in an air tight building because the electricity failed while I slept.
> >>> 
> >>> This is not to dismiss some very good building science and its associated research, but I am finding this conversation on interior air quality in air tight buildings a bit disturbing when we end up with buildings so tightly sealed that the occupants are at risk from either the building fabric itself, or even more alarming, from their own breathing!   People would be much healthier outside the building under these circumstances.  Interesting, isn't it, how, if a person feels ill we often take them outside, where they usually feel much better?  We really do need protection from the built environment.  
> >>> 
> >>> I prefer a design approach that minimises the use of expensive, resource gobbling, and complicated materials and systems.  A colleague of mine sums it up thus:
> >>> The.... division is between those who fling open their doors to embrace the day, and those who huddle behind triple glazing worrying whether they are going to be comfortable.   Tony Watkins FNZIA 
> >>> 
> >>> 
> >>> 
> >>> Graeme "Stirrer"
> >>> 
> >>> Graeme North Architects
> >>> 49 Matthew Road
> >>> RD1
> >>> Warkworth 0981
> >>> 
> >>> www.ecodesign.co.nz
> >> 
> >> 
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> Prof. John F Straube, P.Eng.
> www.BuildingScience.com
> 
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