[GSBN] The mechanical ventilation debate

[Tim Owen-Kennedy]

Yes, Yes, and More Please! I love this list and its ability to wake up such
great minds and hearts when the topic calls it forth. And I love that as
soon as I start to add my .02, or what I too sense from my perspective,
someone has already added something more valuable that consumes the time I
could have spent writing by happily reading and re-stretching my
perspective.

Maybe it's the middle child in me, but I see more cross talk than genuine
conflict.

We need more building science, and the current science says build tighter
and ventilate especially when the climate is extreme. And we need better
"intuitive science" - clear, tested and objective understanding for the
less measurable stuff - comfort, natural connection, what's adequate.
Especially when something sets off red flags like building in a way that
might leave us unhealthy or reliant on more or less functional mechanics
when a simpler approach might suffice. Yes, we need to shift both the
dominant building demands functioning and the social paradigms as quickly
and effectively as possible we need to go fast and far. We also make plenty
of mistakes both by assuming we know what we are doing and by being
ignorantly resistant to the shifting our beliefs when the evidence is
contrary.

But what I'm distilling from this discussion is that we shouldn't abandon a
solution just because it's mechanical and we shouldn't let our current
focus on energy efficiency be the last word in what's most significant
about a building. I don't think anyone here is intentionally setting out to
make leaky buildings. And I hear us all preoccupied with the health of the
materials indoors (some of us even working hard on the materials that are
brought in by the occupants which are more and more of the problem). I
would hope that we are all trying to make the most appropriate decisions
for our context. The question for me now is how to measure diminishing
returns on investing in air tightness and in shifting my clients paradigms.
I have made the assumption that the air tightness limit is reached when I
start to need mechanical ventilation and the paradigm limit is reached when
the third angle of explanation still creates misunderstanding.

I for one have gone from not caring as much about leakiness because of our
climate (Ideallic Northern California) to tightening our buildings as much
as is practical. Mostly I'm left wanting to understand more and more about
air tightness and Indoor air quality. As far as I can tell, we collectively
don't understand enough to be certain at this point where to draw the
lines. I have to say that I'm leaning more and more towards having the
option to control how/when/ and through what filters the air is exchanged
in the building. Especially when you consider the variability and timing of
toxins in the indoor and outdoor environments.None of our projects have
warranted an HRV system yet. But, I hope to revisit a 11 year old project
project in a more extreme climate (15 - 113F) and do a blower door test and
several IAQ tests. And look at the operational cost of the deep sandbed
radiant system and fireplace. Find out how much active ventilation they do
and weather they might be good candidates for a retrofit. Hopefully David
Arkin, as the architect of said project, might be interested in joining me.

Until then I'll keep trying to grow my understanding of the measurable and
the unmeasurable. Keeping an eye out for when I might be causing more
problems than I'm solving and/or unconsciously clinging to an unfounded gut
feeling.

Tim

p.s. I, like most of you probably, thought I'd right a quick note of
addition. So much for assumptions. I attribute the length of our replies
and the heat around this topic to a desire to tease out a deeper
understanding. So, thanks again for all your comments and perspectives.

On Sat, Mar 23, 2013 at 11:50 AM, John Swearingen <
jswearingen at skillful-means.com> wrote:

> I guess I'll add my quarter to the meter.  I've also enjoyed this
> conversation, and it has challenged my own prejudices which stem from my
> origins as a fresh-air-hippy-carpenter who grew up in the mild coastal
> climate of California, and whose family doctor always said to leave the
> bedroom window open. We did that and survived, so that proves it was the
> right thing.
>
> We all have to get our oxygen fix, and we also want to live without
> wearing a whole lot of clothes all the time. This discussion is about how
> to get our oxygen--comfortably. It should be noted, to establish a base
> line, that in regions such as Tibet, where people live in tents in the
> snow, everyone bundles up, and the rich have lap dogs as heaters. Often the
> roof is open to the sky, and if rain or snow is coming in, they move to the
> other side of the room.  We don't need to confine ourselves to temperature
> swings of one or two degrees, and it's worth encouraging people to step out
> of the zone as much as possible (and can also save energy)-- it's healthy
> to "endure" larger swings than most mechanical systems allow.  I can
> imagine a more sophisticated set-back thermostat that cools down a building
> incrementally at night, and then warms it gradually in the morning.
>
> Personally, I have another reason to open windows, which is to hear and
> smell what's outside, and to feel, at least a little, the breeze outside.
>  I guess that depends on where you live, but I will say that I did keep a
> window open when I was living in Sweden. Ok, that's a personal choice, and
> not necessarily an energy efficient one, but it was endorsed by my doctor.
>
> Beyond that, I don't have much intelligent to add to this, or any further
> metaphors, such as "membranes" or "sailboats".  I am becoming more
> accepting of HRV's since living in the midst of wildfires huddled up to an
> air purifier, but I still have trouble getting enthusiastic about
> mechanical ventilators--they sound like something for people in a coma.
> Perhaps I reflect prevalent attitudes--most people think an HRV is
> something made by Honda.
>
> I was interested in John's experience in the Bay Area. I guess John had
> not heard Mark Twain's famous quip: *"The coldest winter I ever spent was
> summer in San Francisco."  *
>
> *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).*
>
>
> Funny, I've lived in this area all my life and have* never* had mold
> growing under my futon!  Perhaps this has less to do with leaky, squeaky
> floorboards than, well....may I suggest it could have been because les
> Canadiens were experiencing particularly steamy nights?  We must always be
> careful to understand when conditions are the result of occupant behavior,
> after all....
>
> John
>
>
>
> On Sat, Mar 23, 2013 at 10:16 AM, David Arkin <david at arkintilt.com> wrote:
>
>> Hi All:
>>
>> I for one am loving this debate!  And learning a great deal, some of it
>> about ventilation even.
>>
>> I posit this:  We like to think of a house as a sailboat.  Not only does
>> it need to be a good boat, but one needs to know how to sail it properly.
>>  Some boats are small and simple, others complex, some with pilots who want
>> to take some time off from the constant sailing, and others still that need
>> to sit moored and unattended (aka not have their pipes freeze when no one
>> is on board).
>>
>> Passive survivability is a concept that sums well what it is we should be
>> aiming at:
>> http://www.buildinggreen.com/auth/article.cfm/2006/5/3/Passive-Survivability-A-New-Design-Criterion-for-Buildings/
>>
>> It suggests, in its most basic terms, that if there is a disruption of
>> any sort, your house (or apartment, whatever) isn't going to kill you (or,
>> we might say, your boat will still move, and it certainly won't sink … that
>> a thoughtfully designed and built boat, specific to its locale, can
>> actually sail along with next to no inputs—even none if one so chooses and
>> is a good sailor).
>>
>> Specific to ventilation, we've installed either fans or HRVs, as the code
>> mandates, and then we've put them on timers so they don't have to run 24/7,
>> and also with an override switch so a savvy, uber-energy-conscious owner
>> who prefers to open windows can shut the whole thing down when they want
>> to.  Or turn it back on if they don't want to actively pilot their air
>> quality, or know they're going into several months of living in a tightly
>> sealed up house.
>>
>> The final question is:  Can/should we be offering sailboats to a society
>> that seems to prefer motorboats?  Absolutely!
>>
>> David Arkin
>>
>> On Mar 22, 2013, at 4:42 AM, John Straube <jfstraube at uwaterloo.ca> wrote:
>>
>> Felie, I think you and Robert have probably helped understand the
>> "divide".
>>
>> For people who dont use fridges, or more broadly, measurable amounts of
>> fossil fuels and even worse, electricity, the entire discussion about
>> airtightness, and even insulation, is not relevant.  In these types of
>> buildings, like tents, we have a whole different set of design concerns,
>> and high levels of airtightness is not worth talking about.
>> I was implicitly discussing the 99% of homes 1 billion people live in the
>> western live in.  There are literally billions more people lined up trying
>> to build and get into this type of housing, so the conversation, and the
>> understanding of different types of housing is really important for the
>> environment.
>>
>> People have been building shelter for thousands of years- the reason they
>> built it was to control the interior environment.  Control the people and
>> animals who can enter/leave, control the temperature, light, sound, rain,
>> view, fire, etc.  So, the issue in design and construction is what to
>> control, and how to control it.  It seems that those who advocate leaving
>> windows open in winter for fresh air, or wearing sweaters inside in winter
>> (to avoid simple, low environmental impact options that avoid requiring
>> this) are merely drawing the control line somewhere different than the
>> mainstream.  Thats OK by me.  If you desire 15C in winter, go ahead.  The
>> only problem is, a billion people use a lot of energy to keep the
>> temperature in their houses somewhere between 17 and 22 (according to
>> measurements in numerous countries).  Smaller scale studies show that if
>> you provide homeowners with a low cost means of controlling the temperature
>> (insulation airtightness and good equipment) they tend
>> to run it closer to 20C and the low temperatures go away and people say
>> they are more comfortable and happier.
>>
>> So, if you have a wider temperature range to make you happy, by all means
>> design your house to do so.  Don't sell it to someone else though, or
>> unless it is well insulated and airtight, it will be an environmental
>> burden when the other 99% move in (like the old house of my neighbours).
>>
>> But while making those houses, please dont make unsubstantiated claims
>> about the poor health and safety of houses that are able to control the
>> comfort and air quality with very few operating or embodied resources.
>>    Airtight homes with mechanical ventilation have better air quality on
>> average than homes built 20, 30, 50 years ago.  Homes with good
>> airtightness and insulation survive interruptions in power for much longer
>> with fewer problems than "old" leaky and uninsulated houses. This is a
>> major advantage for them.  Airtight homes are not hermetically sealed
>> freezers that children will suffocate in.  A ludicrous claim with no
>> substantiation possible.  Tens of thousands of houses with 1.5ACH at 50 Pa
>> have been built and survived power outages of various lengths, all with
>> flying colours, with better outcomes than old homes.
>>
>> I certainly share the concerns with "highly engineered" and complex
>> houses.  Certainly I dont believe in such houses, although there is a
>> modest segment of the population who wants their houses to be like iPhones,
>> shiny glitzy and obsolete in a few years.  But I dont.  I want simple,
>> robust houses that are affordable, comfortable, healthy, durable and, very
>> importantly, consume as few resources over their life as practical.
>>  Simple, airtight, insulated houses are one of the best formulas for
>> achieving my list of goals.  There are others, but that is the one I
>> choose.  And that is what enamours me of systems like straw bale.  They
>> tend to be simple, square homes, with exceptional levels of insulation and
>> the possibility (as Chris Magwood has proven) of being very airtight.
>>
>> So I submit we may be talking past each other.
>> I am trying to design houses for the 99%.
>> Others are trying to design for special needs (I guess lack of needs).
>> And yet others are looking for a social change that would make people not
>> want electric lights, fridges, temperature ranges in the 20C/68F range.
>>
>> If we dont confuse our goals, we may understand each other better.  Did I
>> get it right?
>>
>> On 2013-03-22, at 6:48 AM, Feile Butler <feile at mudandwood.com>
>> wrote:
>>
>> I've been thinking about why has the mechanical ventilation debate been
>> getting under everyone's skin so much. I think Robert Riversong's post
>> echoes how I feel about it.
>>
>> "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."
>>
>> John Straube made the point that we are all happy to use electricity for
>> our fridges and computers, so why not our mechanical ventilation systems?
>>
>>
>> Prof. John F Straube, P.Eng.
>> www.BuildingScience.com
>>
>>
>>
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>>
>>
>> *  *  *  *  *
>> Arkin Tilt Architects
>> Ecological Planning & Design
>>
>> Please Support my 2013 CA Climate Ride (320 mile bicycle ride from Eureka
>> to San Francisco, May 19-23, with a fundraising goal of $3,000 to
>> support Straw-Bale outreach)
>>
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>> Thank you!
>>
>> David Arkin, AIA, Architect
>> LEED Accredited Professional
>> CA #C22459/NV #5030
>>
>> 1101 8th St. #180, Berkeley, CA  94710
>> 510/528-9830 ext. 2#
>> www.arkintilt.com
>>
>> "There is no way to peace. Peace is the way."
>> — A. J. Muste
>>
>>
>>
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>
>
> --
> John Swearingen
> Skillful Means Design & Construction
> 2550 9th Street   Suite 209A
> Berkeley, CA   94710
> 510.849.1800 phone
> 510.849.1900 fax
>
> Web Site:  http://www.skillful-means.com
> Blog:         https://skillfulmeansdesign.wordpress.com
>
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-- 
Tim Owen-Kennedy, Owner
Vital Systems, natural building & design
P O Box 751, Ukiah, CA 95482
www.vitalsystems.net
888.859.6336
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