Re: ASHRAE Ventilation Recommendations and Science

[Guest guest]

Danny,

The occupants (and their activities) will be pollution sources even if you eliminate (not likely) all the other sources. Yes, you need fresh air ventilation.

A popular opinion among building science professionals is to build the home as tightly as possible, then provide fresh dilution air from a known and controlled location.

Take a look at some of the info from Joe Lstiburek and others at http://www.buildingscience.com/index_html.

Curtis Redington, RS

Environmental Quality Specialist

City of Wichita Dept. of Environmental Health

-----Original Message-----From: iequality [mailto:iequality ]On Behalf Of dannyk2002Sent: Thursday, January 03, 2008 1:20 PMTo: iequality Subject: ASHRAE Ventilation Recommendations and Science

Hello,I have searched your archives for a while now and cannot find ananswer to my question.Is there a need for dedicated fresh air ventilation in a new home ifsteps are made to avoid contaminants?Here is my premise.Indoor air quality is primarily a concern with the following:Asbestos - should not be an issue in new homeCarbon Monoxide, Nitrogen Oxide - should not be an issue with no gasburning devices.Formaldehyde - I am not sure of all the components going into thehouse, but should be able to limit it significantly.Household chemicals - we can control this and do.Microorganisms, allergens and mold - Of these, the only one I worryabout is mold induced structural damage, which might even be worse ifhigher humidity air is brought in. If humidity in the house iscontrolled, this should not be an issue.Pesticides - we can control thisRadon - not an issue in this area as far as I am aware otherwise weshould probably vent below the foundation,Tobacco - will not be an issueAlthough I understand how an old home with gas appliances, smokers, nohumidity control, etc will have problems, that is not the house I amtalking about. It seems that bringing in hot, humid air on an ozone alert day here innorth Texas will do way more harm than good. I have asked thisquestion on a few forums and usually receive an answer that "becauseASHRAE says so." What I would like is actual research to back upASHRAE's claims. Especially research related to my specific issues.Any help would be appreciated.Thanks,Danny

[Guest guest]

Dear Danny:

I suspect it impossible to completely eliminate air contaminants from an

occupied indoor space, if only because of the bioeffluents generated by the

people themselves, not to mention the need to mange the moisture generated by

the people and their activities.

As an example, increased ventilation, beyond the minimums recommended by ASHRAE,

have been shown to reduce the transmission of cold and flu viruses, at least as

measured by short-term absenteeism in offices.

I'd go into more detail if you want, I just don't have the time now.

W. Bearg, PE, CIH

--

LIFE ENERGY ASSOCIATES

20 Darton Street

Concord, MA 01742-5710

www.LifeEnergyAssoc.com

-------------- Original message ----------------------

> Hello,

> I have searched your archives for a while now and cannot find an

> answer to my question.

> Is there a need for dedicated fresh air ventilation in a new home if

> steps are made to avoid contaminants?

> Here is my premise.

> Indoor air quality is primarily a concern with the following:

> Asbestos - should not be an issue in new home

> Carbon Monoxide, Nitrogen Oxide - should not be an issue with no gas

> burning devices.

> Formaldehyde - I am not sure of all the components going into the

> house, but should be able to limit it significantly.

> Household chemicals - we can control this and do.

> Microorganisms, allergens and mold - Of these, the only one I worry

> about is mold induced structural damage, which might even be worse if

> higher humidity air is brought in. If humidity in the house is

> controlled, this should not be an issue.

> Pesticides - we can control this

> Radon - not an issue in this area as far as I am aware otherwise we

> should probably vent below the foundation,

> Tobacco - will not be an issue

> Although I understand how an old home with gas appliances, smokers, no

> humidity control, etc will have problems, that is not the house I am

> talking about.

> It seems that bringing in hot, humid air on an ozone alert day here in

> north Texas will do way more harm than good. I have asked this

> question on a few forums and usually receive an answer that " because

> ASHRAE says so. " What I would like is actual research to back up

> ASHRAE's claims. Especially research related to my specific issues.

> Any help would be appreciated.

> Thanks,

> Danny

>

>

>

[Guest guest]

Danny,

has given you some good direction. Check out the list of

bioeffluents in Table 2.2 of this article:

http://www.invironment.com/research/v2n3f1c.pdf

You will find that C02 levels can rise considerably in a tight home

without mechanical ventilation. Carbon dioxide in and of itself is

not typically a health concern (at common indoor concentrations), but

rather it serves as a surrogate.

Your question was do you " need dedicated fresh air ventilation " . I

would answer that you need ventilation, whether you get it naturally

or mechanically is up to you. The advantage of mechanical ventilation

is that the outdoor air is conditioned before being delivered to the

space. Natural ventilation can bring in heat, humidity, particulate

and several other contaminants. ASHRAE Standard 62.2-2007 allows both

options.

Regards,

Ian Cull, PE, CIEC, CMC

Indoor Sciences, Inc.

phone x205

icull@...

www.indoorsciences.com

>

> Dear Danny:

>

> I suspect it impossible to completely eliminate air contaminants

from an occupied indoor space, if only because of the bioeffluents

generated by the people themselves, not to mention the need to mange

the moisture generated by the people and their activities.

>

> As an example, increased ventilation, beyond the minimums

recommended by ASHRAE, have been shown to reduce the transmission of

cold and flu viruses, at least as measured by short-term absenteeism

in offices.

>

> I'd go into more detail if you want, I just don't have the time now.

>

>

>

> W. Bearg, PE, CIH

>

> --

> LIFE ENERGY ASSOCIATES

> 20 Darton Street

> Concord, MA 01742-5710

> www.LifeEnergyAssoc.com

>

>

> -------------- Original message ----------------------

>

> > Hello,

> > I have searched your archives for a while now and cannot find an

> > answer to my question.

> > Is there a need for dedicated fresh air ventilation in a new home if

> > steps are made to avoid contaminants?

> > Here is my premise.

> > Indoor air quality is primarily a concern with the following:

> > Asbestos - should not be an issue in new home

> > Carbon Monoxide, Nitrogen Oxide - should not be an issue with no gas

> > burning devices.

> > Formaldehyde - I am not sure of all the components going into the

> > house, but should be able to limit it significantly.

> > Household chemicals - we can control this and do.

> > Microorganisms, allergens and mold - Of these, the only one I worry

> > about is mold induced structural damage, which might even be worse if

> > higher humidity air is brought in. If humidity in the house is

> > controlled, this should not be an issue.

> > Pesticides - we can control this

> > Radon - not an issue in this area as far as I am aware otherwise we

> > should probably vent below the foundation,

> > Tobacco - will not be an issue

> > Although I understand how an old home with gas appliances, smokers, no

> > humidity control, etc will have problems, that is not the house I am

> > talking about.

> > It seems that bringing in hot, humid air on an ozone alert day here in

> > north Texas will do way more harm than good. I have asked this

> > question on a few forums and usually receive an answer that " because

> > ASHRAE says so. " What I would like is actual research to back up

> > ASHRAE's claims. Especially research related to my specific issues.

> > Any help would be appreciated.

> > Thanks,

> > Danny

> >

> >

> >

>

[Guest guest]

Thank you for your response. I have heard the argument that ventilation is needed to take care of the "toxic" emissions of the inhabitants but have not seen anything that supports it in a residence. An office full of people is quite a different situation.It doesn't make sense that I can avoid exposure to my children's viruses by having fresh air ventilation unless I never went near them. Viruses are generally transmitted 2 ways, airborne and orally. For airborne viruses, it takes a pretty good load of them breathed in at one time, otherwise our bodies immune systems can fight them off. Most viruses are transmitted when we get them on our hands and then put them in our mouths (ie eating). This route is more likely to cause problems because the load of organisms can be much larger. I don't see ventilation helping here at all.The other emission often cited is CO2. This one seems even more unlikely unless we invite dozens

of people over and don't run spot ventilation or open a door for days. I have no studies to support my hypothesis and do not claim to have the answer. I am just looking for what science ASHRAE's recommendations were based on.In regards to Dr. Lsitburek's writings and research, I am a huge fan of him and his work. He is one of the few true building scientists around. He regularly writes and will tell you that ASHRAE's recommendations do not make sense for hot humid climates. He says he has not been able to convince the rest of the Board to update their recommendations and make them climate specific.Thank you,Danny

[Guest guest]

My point is specifically in a house with no fossil fuel combustion, no

radon and good humidity control to prevent mold.

If a thorough attempt to limit VOC's like formaldehyde is made, and

the house is thoroughly ventilated prior to occupation, have there

been any studies that show ASHRAE recommendations are beneficial?

Thank you,

Danny

>

> " should not be an issue " - BUT in reality formaldehyde, radon, mold,

carbon monoxide (from any fossil fue combustion) , etc are big issues.

[Guest guest]

,

An inexpensive IAQ monitor I am familiar with is the HOBO by

Onset.

I’ve attached a .pdf file about it. You can also go

to their web-site at http://www.onsetcomp.com/

Jeff

[Guest guest]

Dear Jeff:

Thanks for the info.

--

LIFE ENERGY ASSOCIATES

20 Darton Street

Concord, MA 01742-5710

www.LifeEnergyAssoc.com

-------------- Original message ----------------------

> ,

>

>

>

> An inexpensive IAQ monitor I am familiar with is the HOBO by Onset.

>

>

>

> I've attached a .pdf file about it. You can also go to their web-site at

> http://www.onsetcomp.com/

>

>

>

> Jeff

>