my office is killing me - jeffrey c. may

Jeffrey C. May, M.A.May Indoor Air Investigations, LLC

Tyngsborough, MA

My Office is Killing Me:Surviving the

Sick Building Syndrome

Sponsored by MassRecycle,Bentley University, 6/15/10 We have taken andWe have taken and

analyzed byanalyzed bymicroscopy overmicroscopy over

25,000 air and dust25,000 air and dustsamples.samples.

Since 1992,Since 1992,we have completedwe have completed

more than 1,500more than 1,500““sick buildingsick building

investigationsinvestigations”” ininhomes, schools,homes, schools,businesses andbusinesses and

offices.offices.

May Indoor Air Investigations LLC

Even LEEDBuildings

haveProblems

May Indoor Air Investigations LLC© 2009 Stata-artslibraryMay Indoor Air Investigations LLC

About 40% of Our Energy IsConsumed By Buildings

Green buildings must be energy efficient

Increased efficiency of mechanicalequipment is mandated

Well-insulated and “tight” buildingssave energy


But fresh air must besupplied.

This requires ENERGY andmechanical systems with

ducts.


15 cubic feet of fresh airper occupant per minute inschools, 20 cfm in offices

This air must beheated in winter and

cooled and dried in summer


Windows that only openWindows that only openwhen they fall outwhen they fall out

All the air webreathe indoors

has passedthrough themechanical

system:

The Dark Passage


© 2008 J. May

© 2002 Rick Hughes

The dark passagethrough ducts


© 2008 J. May

The dark passageMay Indoor Air Investigations LLC© 2008 J. May

Why do we have so manyIAQ problems?

Part of the answer is mold!May Indoor Air Investigations LLC© 2009 J. May

Tip:There should be no

exposed fibrous liningmaterial near a coolingcoil or within about 20feet of the air handler

supplyMay Indoor Air Investigations LLC

The Most Common ProblematicIndoor Mold Genera from

A/C Systems:

Cladosporium

Aspergillus

Penicillium


May Indoor Air Investigations LLC © 2009 J. May

Cladosporium Mold on Fiberglassfrom A/C liner

Skin scale

May Indoor Air Investigations LLC© 2009 J. May

Cladosporium mold in the air froman A/C supply


Dirty Cladosporium spores in theair from an A/C supply


© 2009 J. May

Aspergillus mold in the airfrom an A/C supply

From the office of client with hypersensitivity pneumonitis

Skin scales

Aspergillus

Why Does Mold Grow?

FoodOxygen

Correct temperature rangeMoisture


Dew PointThe dew point is the temperature at

which moisture in air starts to condense

On dry days, the dew point is low

On humid days, the dew point is high

May Indoor Air Investigations LLC© 2009 Wikipedia

Dew-point condensation in acrawl space:

85% RHMay Indoor Air Investigations LLC© 2009 J. May

A/C duct

Change in Relative Humidityof 60ºF Dew-Point Air


Mold growthMold growth


Where there is high RH and dust,microbial growth is very likely.

© 2010 J. May

Skin scale

Spores

Skin scale

© 2010 J. May

Aspergillus on a blower blade


All New CommercialBuildings and Most New

Homes Are Built WithCentral Air Conditioning


The Paradox ofAir Conditioning

When air in most climates isWhen air in most climates iscooled, moisture condenses oncooled, moisture condenses on

the cooling coil, wetting anythe cooling coil, wetting anyaccumulated dust.accumulated dust.

WET DUST=MICROBIAL GROWTHWET DUST=MICROBIAL GROWTHMay Indoor Air Investigations LLC

The “Six-HundredSick Structures” Study

We compared 600We compared 600 ““sick housessick houses””toto

300 control homes300 control homesrandomly chosen from thoserandomly chosen from those

that had been inspected as partthat had been inspected as partof preof pre--purchase agreements.purchase agreements.

May Indoor Air Investigations LLC May Indoor Air Investigations LLC© 2008 J. May

0 10 20 30 40 50 60 70

Forced hot airheat

Central airconditioning

Finished/carpeted basements

Wall-to-wallcarpeting

Basementmoisture stains

Percent

Randomly selected homes SHS home

Table I: Comparison of Randomly -Selected Homes and SHS Homes

37%

19%


Moldy Mat on A/C Coil

Mold Growth in A/CMold Growth in A/C--Coil Dust MatCoil Dust Mat

© 2010 J. May May Indoor Air Investigations LLC

White OxideWhite OxideOnOn

MoldyMoldyInsulationInsulation

Near anNear anA/C CoilA/C Coil


Spores from insulation near the A/C coilSpores from insulation near the A/C coil

Mold Spores (Dead or Alive)Mold Spores (Dead or Alive)Cause Allergy and AsthmaCause Allergy and Asthma

SymptomsSymptoms

© 2010 J. May


Microbial Growth Occurs WhereverThere is Dust and a Heat ExchangerThat Cools Air Containing Moisture


© 2010 J. MayRust

Dust

Mold


Dried Bioslime and Rust

A source of “surrogate” allergen

Filtration is the key!!!


© 2010 J. May

NOT with an open slotor typical

furnace filter

Filtration

ASHRAE Guideline Is a Minimum ofMERV 8

For families with allergies, I alwaysrecommend MERV 11.


© 2008 J. May

The Coil isStill Clean AfterTwo Seasons


A/C Systemwith a

MERV-11Media Filter

Most biodegradable particles in theair, such as skin scales, pollen andlint are trapped by a MERV-8 filter.

Preventing the accumulation of dustminimizes the chances for microbial

growth even at high RH.


With efficient filtration there isno mold, no bioslime, no cloggedcondensate pans, no overflowing

air handlers.

Disposable filters such aspleated media filters are best.

(Electronic filters need too frequentcleaning) May Indoor Air Investigations LLC May Indoor Air Investigations LLC

It is essential for any mechanicalequipment to have an efficient filter

if there is air flow anda heat exchanger that cools air or

creates condensate:

Air ConditionersAir ConditionersAirAir--toto--Air Heat ExchangersAir Heat Exchangers

DehumidifiersDehumidifiers

Moldy dust on filter


Window Air Conditioners are not Immune

Original filters areall inadequate!!!

Mold on a Window-A/C Blower


© 2010 J. May

Who is Negligent?

Given what we know,how can a responsiblemanufacturer sell any

appliance having acooling coil with

anything less than aMERV 8 Filter????


The toll of energy efficiency:

The blowers cannot support thestatic pressure of a decent filter.

Mini-split A/C manufacturer:“Unit will not work with MERV-8

filter.”


To avoid bioaerosolproblems:

MERV-8 filters must be used

Coils and blowers must be clean

Avoid exposed fibrous liners


What do you do if you the IAQmakes you sick in an office????

Check the HVAC system first!Look for visual problems

Other common sources of IAQproblems:•Carpets

•VOC off gassingMay Indoor Air Investigations LLC

Can bioaerosol testing tell you ifthere is a problem????

The results depend on thetype of testing.

Testing for culturable (live) sporesalways underestimates the size of

the problem.


Bioaerosol testing shouldalways include total (viable and

non-viable) spore counts

A simple comparison withoutdoor counts may not be

relevant….

if spores indoors are present inchains May Indoor Air Investigations LLC

Some simple “tests”:

Monitor carbon dioxide (PM2200)www.airtest.com

Cover carpet (carpet protector)www.pro-tect.com

Purchase a VOC or CH20 test kitwww.pati-air.com


Some simple “tests”:

For possibly allergenic particles,wear an N-95 particle mask

Temporarily cover supplies

For VOC, try wearing a charcoalrespirator


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

Encourage non-smoking policies

Encourage fragrance-free offices

Avoid unvented solvent use

Attend today’s workshops!May Indoor Air Investigations LLC

© 2009 J. May

All Tight Buildings Must HaveFresh Air

Many will use air-to-air heatexchangers for ventilation.



HRV/ERV Schematic

© 2010 NuTech

© 2009 J. May

HRVHRV’’ss areare ““greengreen””

IndoorAir

Blower

OutdoorAir

Blower

Core

HRVs need maintenance


© 2009 J. May

Fresh-Air Intake Side

Fresh-AirIntake Side


HRV

HRVs are cryingfor

proper filters


© 2009 J. May


Turn-of-the-Century HRV Filterwith Mold Growing in Dust

Precision filtrationPrecision filtration

HRV


HRV with loose, soiled filterMay Indoor Air Investigations LLC© 2009 J. May

HRVs Must Not HaveExposed Fibrous Liner


© 2009 J. May

Surfaces must be cleanable

HRVDefrost “System”

A grow light forduct perfume?


© 2009 J. May

A Temporary Solution:HRV with external, in-line

filtration

HRVOutdoor

Exhaust

Me

dia

filte

r

Indoor

Med

iafil

ter

Supply

MERV-8 MERV-8

Air Air


© 2009 J. May

Drain

Fantech FB6 Inline Filter box


Use MERV-8 instead of MERV-12

An Optimistic Note:HRV Can Improve Air Quality

By Diluting Contaminants


The New Kitchen Cabinets WereOff-Gassing Formaldehyde


The room odor disappearedafter the HRV was turned on. Dehumidifiers need

efficient filtration too!


Dehumidifier MoldMay Indoor Air Investigations LLC

© 2009 J. May

© 2009 J. May

Dehumidifier Snot


Anything with aAnything with acooling coilcooling coil

mustmusthave at least ahave at least a

MERVMERV--88media filter!media filter!


For Manufacturers,It’s Wake-Up TimeLadders, cigarettes,

liquor and evencoffee cups have

consumer warnings!


ItIt’’s time for mechanical equipment tos time for mechanical equipment tocome with a warning label:come with a warning label:

WARNING: The incoming air must befiltered to avoid microbial contamination.

ASHRAE recommends that you use a filterwith a rating of at least MERV-8. Failure to

maintain filtration can lead to illness.

20082006

20042001

Questions?

For PDF of talk: [email protected]

my office is killing me - jeffrey c. may

Education

air handlerpenicillium

ac supply air

withcentral air conditioning

thetwo seasons air

air webreathe indoorshas

control homes central

energy isbut fresh air

be15 cubic feet of fresh