RE: Ventilation and Health

[Guest guest]

Colleagues:

The research published in Indoor Air 2000, Risk of Sick Leave Associated with

Outdoor Air Supply Rate, Humidification, and Occupant Complaints, adds

confirmation to the recent statement that the ASHRAE 62 minimums are not health

standards. In this paper, they compared short-term absentee rates (a measure of

health) in various office spaces of a large company with the CO2 determined

ventilation rates in these spaces. They rated ventilation at moderate at 25

cfm/person or high at 50 cfm/person. They then reported that those exposed to

the lower outdoor air supply rates had an increased risk of short-term sick

leave. This indicates that an office at environment with a ventilation rate of

50 cfm/person is healthier than an office space with only a 25 cfm/person

ventilation rate.

Clearly, managing a building to provide a healthy environment means effectively

managing the ventilation rate. Unfortunately not that many people have the

resources to even know what the ventilation rates are in the office spaces they

manage?

W. Bearg, PE, CIH

Consultant in IEQ, and

--

Director of IAQ Programs

AIRxpert Systems, Inc.

www.AIRxpert.com

[Guest guest]

Dear ,

Regarding the ASHRAE Standard 62 the ventilation rates of 25 or even 50

cfm per person. The Standard does not address ventilation design for

overall system effectiveness. The supply and return or exhaust grilles

and diffusers that are selected by a/e firms, and contractors have

various performance differences, (spread and throw). The actual

location of these diffusers and grilles many times are not installed or

placed in the best location as well.

What I see and I am sure many of you see are very poorly designed HVAC

supply and exhaust/return diffusers/grilles layouts. The reasons are

many. Someone mentioned in an earlier post that the HVAC is unregulated,

or under regulated. Many times we receive calls regarding IAQ

ventilation

issues or concerns. When we conduct a field survey and request an HVAC

Testing Adjusting & Balancing, (TAB) report we rarely if ever see them.

If we do get a chance to see a copy it usually matches the design

drawings

exactly? In most cases the building or office has changed the floor

layout many times without ever modifying or changing the ventilation

system. We see supply diffusers located right next to the return grille.

This prevents even air distribution to the occupied spaces as well. The

list goes on and on.... I'm sure many of the readers of this group have

seen this type of layout first hand as well.

The next time you go out to a restaurant for dinner look up at the

ceiling.

I always do no matter where I am as a force of habit. However when I do

see

a poorly designed HVAC layout I wonder what is the condition of the

equipment that is supposedly providing 15,20,25 cfm of outside treated

air

to me that I can't see? The ventilation rates required per person

according to ASHRAE Standard 62 is set at a minimum. When the minimum

rate is the designer's target and they miss it, it is usually on the

down-side. When you couple that with poor initial design layout along,

several office occupant changes, with no proper Testing Adjusting &

Balancing documented reports then its no wonder we have the IAQ

ventilation associated complaints that we have on a daily basis.

Until commissioning is part of the Standard that includes system

performance, with documented TAB reports then I believe these

ventilation complaints will remain as IAQ concerns for our industry,

just my thoughts on the issue.

Best regards,

W.

AIR INDUSTRIES, INC.

Re: Ventilation and Health

Colleagues:

The research published in Indoor Air 2000, Risk of Sick Leave Associated

with Outdoor Air Supply Rate, Humidification, and Occupant Complaints,

adds confirmation to the recent statement that the ASHRAE 62 minimums

are not health standards. In this paper, they compared short-term

absentee rates (a measure of health) in various office spaces of a large

company with the CO2 determined ventilation rates in these spaces. They

rated ventilation at moderate at 25 cfm/person or high at 50 cfm/person.

They then reported that those exposed to the lower outdoor air supply

rates had an increased risk of short-term sick leave. This indicates

that an office at environment with a ventilation rate of 50 cfm/person

is healthier than an office space with only a 25 cfm/person ventilation

rate.

Clearly, managing a building to provide a healthy environment means

effectively managing the ventilation rate. Unfortunately not that many

people have the resources to even know what the ventilation rates are in

the office spaces they manage?

W. Bearg, PE, CIH

Consultant in IEQ, and

--

Director of IAQ Programs

AIRxpert Systems, Inc.

www.AIRxpert.com

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[Guest guest]

Dr. on:

thanks for your continuing contributions to a meaningful dialog in

this forum.

the name of the multidisciplinary group was actually " EUROVEN " .

Jan Sundell, Editor-in-chief of the journal, Indoor Air, and fellow

member of ASHRAE's Environmental Health Committee, played a key role

in compiling this data.

following is the abstract:

----------------

Abstract

Scientific literature on the effects of ventilation on health,

comfort, and productivity in non-industrial indoor environments

(offices, schools, homes, etc.) has been reviewed by a

multidisciplinary group of European scientists, called EUROVEN, with

expertise in medicine, epidemiology, toxicology, and engineering. The

group reviewed 105 papers published in peer-reviewed scientific

journals and judged 30 as conclusive, providing sufficient

information on ventilation, health effects, data processing, and

reporting, 14 as providing relevant background information on the

issue, 43 as relevant but non-informative or inconclusive, and 18 as

irrelevant for the issue discussed. Based on the data in papers

judged conclusive, the group agreed that ventilation is strongly

associated with comfort (perceived air quality) and health [sick

Building Syndrome (SBS) symptoms, inflammation, infections, asthma,

allergy, short-term sick leave], and that an association between

ventilation and productivity (performance of office work) is

indicated. The group also concluded that increasing outdoor air

supply rates in non-industrial environments improves perceived air

quality; that outdoor air supply rates below 25 l/s per person

increase the risk of SBS symptoms, increase short-term sick leave,

and decrease productivity among occupants of office buildings; and

that ventilation rates above 0.5 air changes per hour (h1) in homes

reduce infestation of house dust mites in Nordic countries. The group

concluded additionally that the literature indicates that in

buildings with air-conditioning systems there may be an increased

risk of SBS symptoms compared with naturally or mechanically

ventilated buildings, and that improper maintenance, design, and

functioning of air-conditioning systems contributes to increased

prevalence of SBS symptoms.

Practical Implications

Ventilation requirements in many existing guidelines and standards

may be too low to protect occupants of offices, schools, and homes

from health and comfort problems and may not be optimal for human

productivity. Higher ventilation rates can increase energy costs in

relation to building operation, but these can be reduced by lowering

pollution loads on the air indoors, e.g., by prudent and systematic

maintenance of heating/ventilation/air-conditioning (HVAC) systems

and by reducing superfluous pollution sources indoors. Energy costs

can also be reduced by using efficient heat recovery systems. Source

control and new ways of conditioning air are required.

-----------------

respectfully submitted,

Wane

<><><><><><><><><><><><>

Wane A. Baker, P.E., CIH, RPIH

Director, Air Quality Services

" Bad air gets you down "

MICHAELS ENGINEERING INC.

811 Monitor Street, Suite 100

PO Box 2377

La Crosse, Wisconsin 54602

Phone , ext. 484

Cell

Fax

mailto:wab@...

On the web at: http://www.michaelsengineering.com

" To love what you do and feel that it matters - how could anything be

more fun? "

- Graham

>

> The European AIRVENT group has published an interesting literature

review on the association between ventilation rate and various health

endpoints:

>

> Wargocki P, Sundell J, Bischof W, Brundrett G, Fanger PO,

Gyntelberg F, Hanssen SO, on P, Pickering A, Seppänen O &

Wouters P (2002) Ventilation and health in nonindustrial indoor

environments. Report from a European multidisciplinary scientific

consensus meeting. Indoor Air, 12, 113-128

>

> on

>

> __________________________________________________________

>

> Dr T C on, BSc, PhD, CBiol, FIBiol

[Guest guest]

Dear Wane:

Since you point out the importance of providing generous ventilation in achieving a healthy and productive working environment, this raises the question as to the best way to manage the amount of ventilation provided in a building. From my experience, the comment that you can't manage something unless you're monitoring it applies to ventilation as well as energy. In my experience, the potentially most accurate approach to obtaining feedback on the actual amount of ventilation provided in a large building is with carbon dioxide (CO2) monitoring. Of the various options for this monitoring, the greatest accuracy is achieved with the shared-sensor approach. This is because one CO2 sensor is shared for all of the indoor locations as well as the outdoors location. This accuracy is achieved because the ventilation rate determination is a function of the difference between the peak indoor CO2 values and the outdoor CO2 value. Using the same sensor to measure at both locations eliminates the potential error if the multiple sensors are used and they add a measure of uncertainty as they may be calibrated differently. Also, with the shared-sensor approach, there is only one CO2 sensor to keep calibrated, as opposed to a building full.

I was wondering if you had any experience with CO2 monitoring and had any advice to offer.

Sincerely, W. Bearg, PE, CIH

Director of IAQ Programs AIRxpert Systems, Inc. www.AIRxpert.com

-------------- Original message -------------- Dr. on:thanks for your continuing contributions to a meaningful dialog in this forum.the name of the multidisciplinary group was actually "EUROVEN". Jan Sundell, Editor-in-chief of the journal, Indoor Air, and fellow member of ASHRAE's Environmental Health Committee, played a key role in compiling this data. following is the abstract:----------------Abstract Scientific literature on the effects of ventilation on health, comfort, and productivity in non-industrial indoor environments (offices, schools, homes, etc.) has been reviewed by a multidisciplinary group of European scientists, called EUROVEN, with expertise in medicine, epidemiology, toxicology, and engineering. The group reviewed 105 papers published in peer-reviewed scientific journals and judged 30 as conclusive, providing sufficient information on ventilation, health effects, data processing, and reporting, 14 as providing relevant background information on the issue, 43 as relevant but non-informative or inconclusive, and 18 as irrelevant for the issue discussed. Based on the data in papers judged conclusive, the group agreed that ventilation is strongly associated with comfort (perceived air quality) and health [sick Building Syndrome (SBS) symptoms, inflammation, infections, asthma, allergy, short-term sick leave], and that an association between ventilation and productivity (performance of office work) is indicated. The group also concluded that increasing outdoor air supply rates in non-industrial environments improves perceived air quality; that outdoor air supply rates below 25 l/s per person increase the risk of SBS symptoms, increase short-term sick leave, and decrease productivity among occupants of office buildings; and that ventilation rates above 0.5 air changes per hour (h1) in homes reduce infestation of house dust mites in Nordic countries. The group concluded additionally that the literature indicates that in buildings with air-conditioning systems there may be an increased risk of SBS symptoms compared with naturally or mechanically ventilated buildings, and that improper maintenance, design, and functioning of air-conditioning systems contributes to increased prevalence of SBS symptoms.Practical Implications Ventilation requirements in many existing guidelines and standards may be too low to protect occupants of offices, schools, and homes from health and comfort problems and may not be optimal for human productivity. Higher ventilation rates can increase energy costs in relation to building operation, but these can be reduced by lowering pollution loads on the air indoors, e.g., by prudent and systematic maintenance of heating/ventilation/air-conditioning (HVAC) systems and by reducing superfluous pollution sources indoors. Energy costs can also be reduced by using efficient heat recovery systems. Source control and new ways of conditioning air are required.-----------------respectfully submitted,Wane<><><><><><><><><><><><>Wane A. Baker, P.E., CIH, RPIHDirector, Air Quality Services"Bad air gets you down"MICHAELS ENGINEERING INC.811 Monitor Street, Suite 100PO Box 2377 La Crosse, Wisconsin 54602Phone , ext. 484Cell Fax mailto:wab@...On the web at: http://www.michaelsengineering.com "To love what you do and feel that it matters - how could anything be more fun?"- Graham> > The European AIRVENT group has published an interesting literature review on the association between ventilation rate and various health endpoints:> > Wargocki P, Sundell J, Bischof W, Brundrett G, Fanger PO, Gyntelberg F, Hanssen SO, on P, Pickering A, Seppänen O & Wouters P (2002) Ventilation and health in nonindustrial indoor environments. Report from a European multidisciplinary scientific consensus meeting. Indoor Air, 12, 113-128> > on> > __________________________________________________________> > Dr T C on, BSc, PhD, CBiol, FIBiol