My Office Is Killing Me - Jeffrey C. May

Since 1992, Even LEED
My Office is Killing Me: we have completed
more than 1,500
more than 1,500 Buildings
Surviving the “sick building have
Sick Building Syndrome investigations” in
investigations”
Problems
homes, schools,
businesses and
offices.
Sponsored by MassRecycle,
Bentley University, 6/15/10 We have taken and
analyzed by
microscopy over
Jeffrey C. May, M.A. 25,000 air and dust
May Indoor Air Investigations, LLC samples.
Tyngsborough, MA May Indoor Air Investigations LLC
May Indoor Air Investigations LLC
May © 2009 Stata-artslibrary
Indoor Air Investigations LLC

About 40% of Our Energy Is But fresh air must be 15 cubic feet of fresh air
Consumed By Buildings supplied. per occupant per minute in
schools, 20 cfm in offices
Green buildings must be energy efficient
This requires ENERGY and
Increased efficiency of mechanical mechanical systems with This air must be
equipment is mandated ducts. heated in winter and
Well-insulated and “tight” buildings cooled and dried in summer
save energy
May Indoor Air Investigations LLC May Indoor Air Investigations LLC May Indoor Air Investigations LLC

All the air we
breathe indoors
has passed © 2002 Rick Hughes

through the © 2008 J. May

mechanical
system:

The Dark Passage The dark passage
Windows that only open
when they fall out
© 2008 J. May
through ducts The dark passage
May Indoor Air Investigations LLC May Indoor Air Investigations LLC © 2008 J. May May Indoor Air Investigations LLC

Tip: The Most Common Problematic
Why do we have so many
Indoor Mold Genera from
IAQ problems? There should be no A/C Systems:
exposed fibrous lining
Cladosporium
material near a cooling
coil or within about 20 Aspergillus
feet of the air handler
Penicillium
Part of the answer is mold! supply
© 2009 J. May May Indoor Air Investigations LLC May Indoor Air Investigations LLC May Indoor Air Investigations LLC

Cladosporium Mold on Fiberglass Cladosporium mold in the air from Dirty Cladosporium spores in the
from A/C liner an A/C supply air from an A/C supply
Skin scale

© 2009 J. May
May Indoor Air Investigations LLC © 2009 J. May © 2009 J. May May Indoor Air Investigations LLC May Indoor Air Investigations LLC

Aspergillus mold in the air
from an A/C supply Dew Point
Skin scales Why Does Mold Grow ?
The dew point is the temperature at
which moisture in air starts to condense
Food
Aspergillus Oxygen On dry days, the dew point is low

Correct temperature range On humid days, the dew point is high
From the office of client with hypersensitivity pneumonitis Moisture
© 2009 J. May
© 2009 J. May © 2009 Wikipedia

© 2010 J. May
A/C duct
Mold growth

Dew-point condensation in a Change in Relative Humidity
of 60ºF Dew-Point Air
crawl space: Where there is high RH and dust,
85% RH microbial growth is very likely.

Aspergillus on a blower blade All New Commercial The Paradox of
Buildings and Most New
Skin scale Air Conditioning
Homes Are Built With
Central Air Conditioning When air in most climates is
cooled, moisture condenses on
the cooling coil, wetting any
Spores accumulated dust.
Skin scale
WET DUST=MICROBIAL GROWTH
© 2010 J. May
© 2010 J. May May Indoor Air Investigations LLC
May Indoor Air Investigations LLC May Indoor Air Investigations LLC

Table I: Comparison of Randomly -Selected Homes and SHS Homes
The “Six-Hundred Randomly selected homes SHS home

Sick Structures” Study Basement
moisture stains
Wall-to-wall
We compared 600 “sick houses”
houses” carpeting

to Finished/carpet
ed basements
300 control homes Central air
37%
19%
conditioning
randomly chosen from those Forced hot air
that had been inspected as part heat Moldy Mat on A/C Coil
of pre-purchase agreements.
pre- 0 10 20 30 40
Percent
50 60 70
May Indoor Air Investigations LLC © 2008 J. May May Indoor Air Investigations LLC

Mold Spores (Dead or Alive)
White Oxide Cause Allergy and Asthma
Mold Growth in A/C-Coil Dust Mat
On Symptoms
Moldy
Insulation
Near an
A/C Coil

Spores from insulation near the A/C coil
© 2010 J. May


Microbial Growth Occurs Wherever Dried Bioslime and Rust
There is Dust and a Heat Exchanger Filtration is the key!!!
That Cools Air Containing Moisture

Dust

Mold

NOT with an open slot
© 2010 J. May
A source of “surrogate” allergen or typical
Rust © 2010 J. May
May Indoor Air Investigations LLC
© 2010 J. May
May Indoor Air Investigations LLC furnace filter May Indoor Air Investigations LLC

The Coil is
Filtration Still Clean After Most biodegradable particles in the
Two Seasons air, such as skin scales, pollen and
ASHRAE Guideline Is a Minimum of lint are trapped by a MERV-8 filter.
MERV 8
© 2008 J. May

For families with allergies, I always A/C System Preventing the accumulation of dust
recommend MERV 11. with a minimizes the chances for microbial
MERV-11 growth even at high RH.
Media Filter

With efficient filtration there is It is essential for any mechanical
equipment to have an efficient filter Window Air Conditioners are not Immune
no mold, no bioslime, no clogged
condensate pans, no overflowing if there is air flow and
air handlers. a heat exchanger that cools air or
creates condensate:
Moldy dust on filter
Disposable filters such as
Air Conditioners
pleated media filters are best.
Air- to-
Air-to-Air Heat Exchangers
Original filters are
(Electronic filters need too frequent Dehumidifiers all inadequate!!!
cleaning)May Indoor Air Investigations LLC
May Indoor Air Investigations LLC May Indoor Air Investigations LLC © 2010 J. May

Mold on a Window-A/C Blower
Who is Negligent? The toll of energy efficiency:

Given what we know, The blowers cannot support the
how can a responsible static pressure of a decent filter.
manufacturer sell any
appliance having a Mini-split A/C manufacturer:
cooling coil with “Unit will not work with MERV-8
anything less than a filter.”
© 2010 J. May MERV 8 Filter????
© 2009 J. May

To avoid bioaerosol What do you do if you the IAQ Can bioaerosol testing tell you if
makes you sick in an office???? there is a problem????
problems:
Check the HVAC system first! The results depend on the
MERV-8 filters must be used Look for visual problems type of testing.
Coils and blowers must be clean Other common sources of IAQ
Testing for culturable (live) spores
problems:
Avoid exposed fibrous liners always underestimates the size of
•Carpets
the problem.
•VOC off gassing
© 2009 J. May

Bioaerosol testing should Some simple “tests”: Some simple “tests”:
always include total (viable and
non-viable) spore counts Monitor carbon dioxide (PM2200) For possibly allergenic particles,
www.airtest.com wear an N-95 particle mask
A simple comparison with Cover carpet (carpet protector)
outdoor counts may not be www.pro-tect.com Temporarily cover supplies
relevant…. Purchase a VOC or CH20 test kit
www.pati-air.com For VOC, try wearing a charcoal
if spores indoors are present in
respirator
chains May Indoor Air Investigations LLC May Indoor Air Investigations LLC May Indoor Air Investigations LLC

For more tips, guidance and information
on how to read reports: To avoid VOC problems:

Encourage non-smoking policies All Tight Buildings Must Have
Fresh Air
Encourage fragrance-free offices

Avoid unvented solvent use Many will use air-to-air heat
exchangers for ventilation.
Attend today’s workshops!
© 2009 J. May

HRV/ERV Schematic Indoor Outdoor
Air Air HRVs need maintenance
Blower Blower

Core

HRV’
HRV’ s are “green”
green” Fresh-Air Intake Side
© 2009 J. May
© 2010 NuTech


HRVs are crying Turn-of-the-Century HRV Filter
for with Mold Growing in Dust
proper filters

HRV

Fresh-Air
Intake Side © 2009 J. May

© 2009 J. May © 2009 J. May May Indoor Air Investigations LLC
May Indoor Air Investigations LLC May Indoor Air Investigations LLC

HRV HRVs Must Not Have
Exposed Fibrous Liner

Surfaces must be cleanable
HRV with loose, soiled filter
Precision filtration © 2009 J. May
© 2009 J. May May Indoor Air Investigations LLC © 2009 J. May May Indoor Air Investigations LLC May Indoor Air Investigations LLC

A Temporary Solution: Fantech FB6 Inline Filter box
HRV HRV with external, in-line
Defrost “System” filtration
Air Exhaust Supply Air

Media filter
HRV

Media filter
A grow light for Outdoor Indoor
duct perfume?
Drain MERV-8
MERV-8

© 2009 J. May
© 2009 J. May Use MERV-8 instead of MERV- 12

An Optimistic Note: The New Kitchen Cabinets Were
HRV Can Improve Air Quality Off-Gassing Formaldehyde
The room odor disappeared
after the HRV was turned on. Dehumidifiers need
efficient filtration too!

By Diluting Contaminants
© 2009 J. May
© 2009 J. May May Indoor Air Investigations LLC May Indoor Air Investigations LLC © 2009 J. May May Indoor Air Investigations LLC

Anything with a
cooling coil
must
have at least a
MERV-8 -8
media filter!
Dehumidifier Snot

© 2009 J. May

Dehumidifier Mold May Indoor Air Investigations LLC © 2009 J. May May Indoor Air Investigations LLC
May Indoor Air Investigations LLC © 2009 J. May

For Manufacturers, It’s time for mechanical equipment to
It’
It’s Wake-Up Time come with a warning label:
Questions?
Ladders, cigarettes,
liquor and even
coffee cups have WARNING: The incoming air must be
consumer warnings! filtered to avoid microbial contamination.
ASHRAE recommends that you use a filter
with a rating of at least MERV-8. Failure to
maintain filtration can lead to illness.
2001
2004

2006
2008
May Indoor Air Investigations LLC For PDF of talk: info@mayindoorair.com

My Office Is Killing Me - Jeffrey C. May

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My Office Is Killing Me - Jeffrey C. May