[Greenbuilding] Stale Air

Mon Dec 13 15:15:32 CST 2010

none of this negates John Salmen's comment that ventilation rates could be
too high when buildings are not occupied or when occupied at lower than
design density--just that CO2 level may not be the way to regulate
ventilation for this effect.

a

*Alan Abrams**
Abrams Design Build LLC*
*A sustainable approach to beautiful space*
alan at abramsdesignbuild.com
www.abramsdesignbuild.com
*202-726-5894 o
202-437-8583 c
202-291-0626 f*

On Mon, Dec 13, 2010 at 9:58 AM, John Straube <jfstraube at gmail.com> wrote:

> Oh and CO kills you at rather low levels.
> Sent from my BlackBerry®
>
> -----Original Message-----
> From: Keith Winston <keith at earthsunenergy.com>
> Sender: greenbuilding-bounces at lists.bioenergylists.org
> Date: Mon, 13 Dec 2010 00:25:03
> To: <greenbuilding at lists.bioenergylists.org>
> Subject: Re: [Greenbuilding] Stale Air
>
> Um, apples and oranges here, no? John is talking about CO2, and Stephen
> responded concerning CO. One is a natural result of breathing, and the
> other generally occurs indoors in significant quantities when a
> combustion appliance is maladjusted. There is no reliable correlation
> between the two.
>
> Keith
>
>
>
>
> On 12/12/2010 10:31 PM, JOHN SALMEN wrote:
> > Sorry Stephen – I know you know all that stuff, I liked the question
> > and was thinking out loud and still thinking out loud. One of the
> > interesting things for me is that when someone is cyanotic or hypoxic
> > in a medical situation it is pretty apparent. Basically co2 drives our
> > breathing as we eliminate it. Chronic high(er) levels of co2 in our
> > built environment may be an issue. It would never be the case that
> > there was not sufficient oxygen – more that the body becomes less able
> > to utilize the oxygen as it becomes less able to eliminate co2 or other
> > mixtures of gases. So we end up with chronic problems.
> >
> > That is one thought and then a companion thought is that co2 is used as
> > an indicator – if it is present at higher levels then other gases are
> > so is a broad measuring tool for IAQ and these gases interact. I think
> > we are allowed approximately double the exterior co2 level for indoor
> > environments. Perhaps that is too high for an aging or health
> > compromised population.
> >
> > Increasingly I think ventilation rates are too low (and people spend
> > too much time indoors but ironically not that much time in their
> > houses). Are we heating and ventilating houses far too much when are
> > unoccupied and then ventilating sufficiently for when they are? How
> > well is demand controlled ventilation actually working?
> >
> > Thanks for the question – has me scratching my head as well.
> >
> > John
> >
> >_JOHN SALMEN ENVIRONMENTAL DESIGN_
> >
> > /4465 UPHILL RD//,. DUNCAN, B.C. CANADA, V9L 6M7/
> >
> > /PH 250 748 7672 FAX 250 748 7612 CELL 250 246 8541/
> >
> > /terrain at shaw.ca/
> >
> > -----------------------------------------------------------------------
> >
> > *From:*Stephen Collette [mailto:stephen at yourhealthyhouse.ca]
> > *Sent:* December 12, 2010 4:44 PM
> > *To:* JOHN SALMEN
> > *Cc:* Greenbuilding at bioenergylists.org
> > *Subject:* Stale Air
> >
> > Thanks for your thoughts John. I am wondering how useful the
> > measurement of CO2 in homes is. I have a CO meter and pull it out on
> > occasion and to my memory have not found anything with it in a home.
> > Typically with a couple of people or small family in a single family
> > dwelling, I wonder whether they alone could ever get the levels up to
> > something dangerous? Now blended families or extended families all
> > living under one roof, I think that may be possible.
> >
> > I'm not disagreeing with you at all, what you are saying is what I talk
> > about too, but again, is it actually valid? I don't know, and hence the
> > head scratching.
> >
> > Grateful for your time thinking about this.
> >
> > Stephen
> >
> > Stephen Collette BBEC, LEED AP, BSSO
> >
> > */Your Healthy House/*-Indoor Environmental Testing & Building Consulting
> >
> > http://www.yourhealthyhouse.ca
> >
> > stephen at yourhealthyhouse.ca <mailto:stephen at yourhealthyhouse.ca>
> >
> > 705.652.5159
> >
> >> Hi,
> >>
> >> There are a lot of adjectives for air – stale, stagnant, dead, fetid…
> >>
> >> Air basically means for us oxygen as a requirement – so stale air
> >> could simply be oxygen poor air.
> >>
> >> .
> >>
> >> With ashrae I guess there is adequate ventilation and inadequate
> >> ventilation and stale would be an excess of unventilated air
> >> (stale??). Ashrae uses co2 concentrations as the indicator for
> >> adequate ventilation so there definition is ppm for various uses.
> >>
> >> In emergency first aid I measure ventilation rates, blood oxygen
> >> levels as well of level of consciousness – all of which could reveal
> >> an emergency condition in students in a classroom at the end of a day
> >> subject to averaged ventilation and subsequent ‘stale’ air. Tidal
> >> volume (breath) is about 500ml with about 14% oxygen and 4.4% co2
> >> exhaled – outside air is about 21% oxygen and .04% co2.
> >>
> >> So a significant amount of c02 is released on each breath in
> >> comparison to the intake – so we could say that ‘stale air’ is any
> >> air exhaled.
> >>
> >> Fun question.
> >>
> >> John
> >>
> >>
> >>
> >>
> >
> >
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>
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