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J.S. Zhang, Syracuse University 4/9/2005 College of Engineering and College of Engineering and Computer Science Computer Science Outline Outline Syracuse University Syracuse University Introduction Introduction Common causes

slide-1
SLIDE 1

J.S. Zhang, Syracuse University 4/9/2005 1

College of Engineering and College of Engineering and Computer Science Computer Science Syracuse University Syracuse University

Material Emissions Material Emissions and Indoor Air Quality (IAQ) and Indoor Air Quality (IAQ)

By

  • Dr. J. S. (Jensen) Zhang

Department of Mechanical, Aerospace, and Department of Mechanical, Aerospace, and Manufacturing Engineering Manufacturing Engineering

Outline Outline

  • Introduction

Introduction

  • Common causes of IAQ problems

Common causes of IAQ problems

  • Typical contaminant sources

Typical contaminant sources

  • Why study material emissions?

Why study material emissions?

  • Material Emission Studies

Material Emission Studies

  • “Finger print”

“Finger print” ---

  • -- What

What VOCs VOCs are emitted ? are emitted ?

  • How fast are the emissions?

How fast are the emissions?

  • Impact of material emissions on IAQ

Impact of material emissions on IAQ

  • Summary

Summary

  • Research needs

Research needs

Common Causes of IAQ Problems Common Causes of IAQ Problems

  • Poor ventilation

Poor ventilation

  • Outdoor and indoor contaminant

Outdoor and indoor contaminant sources sources

  • Perceptions due to

Perceptions due to

  • poor thermal conditions (e.g., high RH)

poor thermal conditions (e.g., high RH)

  • poor lighting

poor lighting

  • high noise level

high noise level

  • job stress, …, etc.

job stress, …, etc. Typical contaminant sources: outdoors Typical contaminant sources: outdoors

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SLIDE 2

J.S. Zhang, Syracuse University 4/9/2005 2

Typical contaminant sources: indoors Typical contaminant sources: indoors Building material emissions Building material emissions

Why Study Material Emissions? Why Study Material Emissions?

  • 300+

300+ VOCs VOCs identified (accounts for identified (accounts for

  • ver 50% indoor contaminants)
  • ver 50% indoor contaminants)
  • Many

Many VOCs VOCs can cause discomfort and can cause discomfort and adverse health effects adverse health effects

  • Indoor VOC concentrations are usually

Indoor VOC concentrations are usually much higher than outdoors much higher than outdoors

Material Emission Studies Material Emission Studies

  • Chemical analysis:

Chemical analysis: What are emitted? What are emitted?

  • ---The “finger print”

The “finger print”

  • Emission rates over time

Emission rates over time --

  • - How fast,

How fast, how long and how much? how long and how much?

  • Impact on Indoor Air Quality (IAQ)

Impact on Indoor Air Quality (IAQ)

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SLIDE 3

J.S. Zhang, Syracuse University 4/9/2005 3

Identification of Identification of VOCs VOCs emitted: headspace analysis emitted: headspace analysis Chemical Analysis Systems (GC/FID and GC/MS) Chemical Analysis Systems (GC/FID and GC/MS) Three Oil Three Oil-

  • based Wood Stains

based Wood Stains -

  • Headspace

Headspace

2 6 .0 2 8 .0 3 .0 3 2 .0 3 4 .0 3 6 .0 3 8 .0 1 2 3 4 5 6 7 8 9 1 e + 7 1 .1 e + 7 1 .2 e + 7 1 .3 e + 7 1 .4 e + 7 1 .5 e + 7 T i m e

  • >

A b u n d a n c e T IC : [ B S B 1 ]W S 1

  • H

S 1 .D 1 7 1 8 1 9 2 1 6 1 5 1 4 1 3 1 2 1 1 1 9 8 7 6 5 4 3 2 1 2 6 . 2 8 . 3 . 3 2 . 3 4 . 3 6 . 3 8 . 1 2 3 4 5 6 7 8 9 1 e + 7 1 . 1 e + 7 1 . 2 e + 7 1 . 3 e + 7 1 . 4 e + 7 1 . 5 e + 7 1 . 6 e + 7 1 . 7 e + 7 1 . 8 e + 7 T i m e

  • >

A b u n d a n c e T I C : [ B S B 1 ] W S 5

  • H

S . D 1 5 1 4 1 6 1 8 1 9 2 1 7 1 3 1 2 1 1 1 9 8 7 6 5 4 3 2 1 2 6 . 2 8 . 3 . 3 2 . 3 4 . 3 6 . 3 8 . 1 2 3 4 5 6 7 8 9 1 e + 7 1 . 1 e + 7 1 . 2 e + 7 1 . 3 e + 7 1 . 4 e + 7 1 . 5 e + 7 1 . 6 e + 7 1 . 7 e + 7 1 . 8 e + 7 1 . 9 e + 7 2 e + 7 2 . 1 e + 7 T i m e

  • >

A b u n d a n c e T I C : [ B S B 1 ] W S 5

  • H

S 1 . D 1 7 1 8 2 1 9 1 6 1 5 1 4 1 3 1 2 1 1 1 9 8 7 6 5 4 3 2 1

2-butanone nonane decane undecane

WS3 WS6 WS9

Two Water Two Water-

  • based (Latex) Paints

based (Latex) Paints – – Headspace Headspace

5 .0 1 .0 1 5 .0 2 .0 2 5 .0 5 1 1 5 2 2 5 3 3 5 4 4 5 T im e

  • >

A b u n d a n ce T IC : 9 8 2 9

  • 6

.D P T 4 ( L a te x )

  • H

e a d s p a ce a ce to n e 2

  • m

e th y l 2

  • p

r

  • p

a n

  • l

1

  • b

u ta n a l

5 .0 1 .0 1 5 .0 2 .0 2 5 .0 2 4 6 8 1 1 2 1 4 1 6 1 8 T im e

  • >

A b u n d a n ce T IC : 9 8 2 9

  • 7

.D P T 6 ( L a te x )

  • H

e a d s p a ce a ce to n e e th y l a ce ta te n

  • b

u ty l e th e r

1-butanol 2-methyl 2-propanol acetone

n-butyl ether

ethyl acetate acetone

PT4 PT6

slide-4
SLIDE 4

J.S. Zhang, Syracuse University 4/9/2005 4 Particleboard (at t= 24 h, by GC/FID) Particleboard (at t= 24 h, by GC/FID)

9 1 1 1 1 2 2 2 2 3 3 3 3 4 4 4 8 1 1 1 1 1 2 2 2 2 2 3 3 3 3 3 4 4 4 4 F i l e n a m e : D : \ R E S E A R C H \ M E \ D R Y _ P R O D \ W O O D \ P A R T B O ~ 1 \ P B 4 \ P B 4
  • 4
. R U N C h a n n e l : A = F I D

1 2 3 4 5 6 7

1 Hexanal 2 α-Pinene 3 Camphene 4 β-Pinene 5 α-Terpinene 6 Limonene 7 γ-Terpinene

Material Emission Studies Material Emission Studies

  • Chemical analysis: What are emitted?

Chemical analysis: What are emitted?

  • ---The “finger print”

The “finger print”

  • Emission rates over time

Emission rates over time --

  • - How fast, how

How fast, how long and how much? long and how much?

  • Environmental chamber testing

Environmental chamber testing

– – Small chambers Small chambers – – Full Full-

  • scale chambers

scale chambers

  • Mathematical modeling

Mathematical modeling

– – Emission models (sources) Emission models (sources) – – Sorption models (sinks) Sorption models (sinks)

  • Impact on Indoor Air Quality (IAQ)

Impact on Indoor Air Quality (IAQ) Small Environmental Chamber Facility Small Environmental Chamber Facility

  • - Testing of sources/sinks, air purifiers, & sensors

Testing of sources/sinks, air purifiers, & sensors

Test Material Test Chamber Air Entry VOCs Sorbent Tube Air Exit Thermal Desorber GC FID Detector

Small Environmental Chamber Facility Small Environmental Chamber Facility at Syracuse University at Syracuse University

Clean air supply Clean air supply Temperature controlled Temperature controlled enclosure enclosure Stainless steel Stainless steel chambers chambers

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SLIDE 5

J.S. Zhang, Syracuse University 4/9/2005 5

A Full A Full-

  • scale Chamber System at NRC

scale Chamber System at NRC VOC emission characteristics of a wood stain VOC emission characteristics of a wood stain

Emission from wood stain: Emission from wood stain:

  • - a three period process

a three period process

Comparison between modeled and measured concentrations Comparison between modeled and measured concentrations

WS2

0.01 0.1 1 10 100 1000 10000 10 20 30 40 50 60 70 80 90 100

Elapsed Time (h)

  • Conc. (mg/m

3)

(Nonane) EXP (Nonane) Model (Decane) EXP (Decane) Model (Undecane) EXP (Undecane) Model (Dodecane) EXP (Dodecane) Model (TVOC) EXP (TVOC) Model

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SLIDE 6

J.S. Zhang, Syracuse University 4/9/2005 6

A CFD Model for “Wet” Coating Materials A CFD Model for “Wet” Coating Materials

Air Air Coating Coating Substrate Substrate Boundary Boundary layer layer Interface Interface

C(t) C(t) C Cs

s(t)

(t)

  • Room flow:

Room flow: Computational Fluid Dynamics (CFD) model Computational Fluid Dynamics (CFD) model

  • Boundary layer: Convective mass transfer model

Boundary layer: Convective mass transfer model

  • Interface:

Interface: Equilibrium sorption model Equilibrium sorption model

  • Coating:

Coating: Evaporation/diffusion Evaporation/diffusion

  • Substrate:

Substrate: Diffusion Diffusion

C(t) C(t) C Cs

s(t)

(t) C Ci

i(t)

(t) Comparison between modeled and measured emission rates Comparison between modeled and measured emission rates

  • -TVOC emissions from wood stain applied on oak substrate (Yang et

TVOC emissions from wood stain applied on oak substrate (Yang et al. al. 1999) 1999)

0.0 1.0 2.0 3.0 0.0 0.5 1.0 1.5 2.0

Elapsed time t (h)

Experiment VB model CFD 0.0001 0.001 0.01 0.1 1 10 0.0 6.0 12.0 18.0 24.0

Elapsed time t (h)

Experiment VB model CFD

  • a. First 2 hours
  • b. First 24 hours

Emission Characteristics Emission Characteristics

“ “Wet” materials: Wet” materials:

  • High initial emission rates and fast

High initial emission rates and fast decay rate decay rate

  • Three emission periods

Three emission periods

  • evaporative controlled initial period

evaporative controlled initial period

  • transition period

transition period

  • diffusion controlled final period

diffusion controlled final period

  • Affected by air velocity

Affected by air velocity

Emission Characteristics Emission Characteristics

Dry materials: Dry materials:

  • Low emission rates and slow decay rate

Low emission rates and slow decay rate

  • Diffusion controlled process

Diffusion controlled process

  • Not significantly affected by air velocity

Not significantly affected by air velocity

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SLIDE 7

J.S. Zhang, Syracuse University 4/9/2005 7

Particleboard (PB Particleboard (PB-

  • 6): small chamber test results

6): small chamber test results

0.001 0.010 0.100 1.000 10.000 100.000

48 96 144 192 240 288 336 384 432 480 528 576 624 672 720 768 816 864

Elapsed Time, h Concentration, ug/L

TVOC Hexanal a-Pinene Camphene Limonene

(36 days)

  • Inside the material

Inside the material

  • At the material

At the material-

  • air interface

air interface

C C = concentration in the material; = concentration in the material; t t = time; = time; D D = effective diffusion coefficient of a VOC in the material; = effective diffusion coefficient of a VOC in the material; x x = the spatial coordinate (assuming 1 = the spatial coordinate (assuming 1-

  • D

D diffusion). diffusion). C Ca

a

= concentration in air at the material = concentration in air at the material-

  • air interface;

air interface; k ke

e

= partition coefficient. = partition coefficient.

A Diffusion Model For Dry Materials A Diffusion Model For Dry Materials

2 2

x C D t C ∂ ∂ = ∂ ∂

a eC

k ) x ( C = =

C C x x

  • C

Ca

a

Air Air E C x x

  • Prediction by a diffusion model

Prediction by a diffusion model

Emission vs Time [Methyl isoButyl Ketone]

0.00 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 50 100 150 200 250 Elapsed Time (hr) R (mg/m^2 hr) Model Exp. RK Model

Elapsed time, hour Elapsed time, hour Emission rate, mg/(m^2 h) Emission rate, mg/(m^2 h)

Measured data Measured data __ Diffusion model __ Diffusion model

  • --- 1

1st

st order decay

  • rder decay

Classification of Building Materials Classification of Building Materials

  • “

“Wet” materials Wet” materials

  • wood stain, polyurethane, floor wax, paint

wood stain, polyurethane, floor wax, paint

  • adhesive, caulking

adhesive, caulking

  • Dry materials

Dry materials

  • particleboard, OSB, plywood

particleboard, OSB, plywood

  • oak, maple, spruce, pine
  • ak, maple, spruce, pine
  • gypsum wallboard, ceiling tile, vinyl tile

gypsum wallboard, ceiling tile, vinyl tile

  • carpet,

carpet, underpad underpad

  • Material assemblies

Material assemblies

  • Wall, floor assemblies, etc..

Wall, floor assemblies, etc..

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SLIDE 8

J.S. Zhang, Syracuse University 4/9/2005 8

VOC Emissions from a multi VOC Emissions from a multi-

  • layer assembly

layer assembly

¼” plywood ¼” plywood // // rubber sub rubber sub-

  • floor tile

floor tile // 5/8” plywood // 5/8” plywood

VOC emissions from a multi VOC emissions from a multi-

  • layer assembly

layer assembly

(Sealed bottom and edge surfaces & complete contacts between layers)

0.000 0.005 0.010 0.015 0.020 0.025 0.030 0.035 100 200 300 400 500 600 700 800 900 Time (hr)

  • Conc. (mg/m3)

Model (Benzene) Experiment (Benzene) Model (Toluene) Experement (Toluene) Model (P-Xylene) Experement (P-Xylene)

VOC emissions from a multi VOC emissions from a multi-

  • layer assembly

layer assembly

(Unsealed bottom and edge surfaces & incomplete contacts)

0.0001 0.001 0.01 0.1 100 200 300 400 500 600 700 800 900 Time (hr) Concentration (mg/m3) Exp (Benzene) Model (Benzene) Exp (Toluene) Model (Toluene) Exp (P-Xylene) Model (P-Xylene)

Sorption (sink) effect: Sorption (sink) effect: dodecane

dodecane on a carpet

  • n a carpet

0.0 0.5 1.0 100 200 300 400 500 600

Elapsed time (h) Conc.(mg/m3)

Sorption Sorption-

  • Phase

Phase Desorption Desorption-

  • Phase

Phase Sink model Sink model No sink No sink Measured Measured

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SLIDE 9

J.S. Zhang, Syracuse University 4/9/2005 9

Effect of Environmental Conditions on VOC Sorption Effect of Environmental Conditions on VOC Sorption (ASHRAE RP (ASHRAE RP-

  • 1097)

1097)

  • a. Painted drywall
  • b. Ceiling tile
  • c. Carpet

Effect of Environmental Conditions on VOC Sorption Effect of Environmental Conditions on VOC Sorption (ASHRAE RP (ASHRAE RP-

  • 1097):

1097): Dodecane Dodecane on carpet

  • n carpet

Time (hr) Normalized Concentration

50 100 150 200 250 300 350 400 450 500 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 1.1 Ref. Low RH High RH Low T. High T. High V. DOD

Material Emission Studies Material Emission Studies

  • Chemical analysis: What are emitted?

Chemical analysis: What are emitted?

  • ---The “finger print”

The “finger print”

  • Emission rates over time

Emission rates over time --

  • - How fast,

How fast, how long and how much? how long and how much?

  • Impact on Indoor Air Quality

Impact on Indoor Air Quality

Principle of IAQ Control Principle of IAQ Control

Flow entrainment & mixing

Q, Cs

C C, V R F

Air diffuser jet Air diffuser jet Return/exhaust Return/exhaust

slide-10
SLIDE 10

J.S. Zhang, Syracuse University 4/9/2005 10

Principle of IAQ Control Principle of IAQ Control

  • Goal:

Goal:

C < C < C Ccrieteria

crieteria

  • Governing equation:

Governing equation:

V V dC dC/ /dt dt = R(t) = R(t) – – Q(t) [C(t) Q(t) [C(t) – – C Cs

s(t)]

(t)] – – F(t) F(t)

Rate of Rate of contaminant contaminant accumulation accumulation Rate of Rate of source source emission emission Rate of Rate of dilution by dilution by ventilation ventilation Rate of Rate of reduction by reduction by purification purification

= = – – – –

A Computer Tool for IAQ Analysis A Computer Tool for IAQ Analysis

  • “

“MEDB MEDB-

  • IAQ”

IAQ”--

  • - Material Emission

Material Emission Database and IAQ Analysis Database and IAQ Analysis

  • A database of sources and sinks

A database of sources and sinks

  • A room simulation model

A room simulation model

Impact of Material Selections and Impact of Material Selections and Ventilation on Indoor Air Quality Ventilation on Indoor Air Quality

MEDB MEDB-

  • IAQ: selecting materials

IAQ: selecting materials MEDB MEDB-

  • IAQ: selecting ventilation rate/schedule

IAQ: selecting ventilation rate/schedule

slide-11
SLIDE 11

J.S. Zhang, Syracuse University 4/9/2005 11

MEDB MEDB-

  • IAQ: predicting the concentrations

IAQ: predicting the concentrations

Summary Summary

  • Material emission studies

Material emission studies

  • The “finger print”

The “finger print” --

  • - What are emitted?

What are emitted?

  • Emission rate over time

Emission rate over time --

  • - How fast and how

How fast and how much? much?

– – Environmental chamber testing Environmental chamber testing – – Mathematical modeling Mathematical modeling – – “Wet” and dry individual materials “Wet” and dry individual materials – – Material assemblies Material assemblies

  • Impact of material emissions on IAQ

Impact of material emissions on IAQ

– – Material emission database Material emission database – – A computer simulation tool for IAQ analysis A computer simulation tool for IAQ analysis

  • Source control, ventilation and air purification

Source control, ventilation and air purification

Research Needs Research Needs

  • VOC emissions and transport in multi

VOC emissions and transport in multi-

  • layer material

layer material systems systems

  • Air leakage paths

Air leakage paths

  • Diffusion through porous materials

Diffusion through porous materials

  • Effect of environmental conditions on

Effect of environmental conditions on

  • VOC emissions, sorption and transport

VOC emissions, sorption and transport

  • Outdoor to indoor contaminant transport

Outdoor to indoor contaminant transport

  • Combined heat, moisture and contaminant

Combined heat, moisture and contaminant transport transport

  • A comprehensive database

A comprehensive database

  • Individual materials and material assemblies

Individual materials and material assemblies

  • An integrated model

An integrated model

  • IAQ and energy analyses

IAQ and energy analyses A Full A Full-

  • scale Thermal & Air Quality Research Facility

scale Thermal & Air Quality Research Facility at Syracuse University at Syracuse University Climate Climate Chamber Chamber (6x12x10 ft) (6x12x10 ft) Test Test “wall” “wall” Indoor Indoor Environmental chamber Environmental chamber (16 ft x12 ft x10 ft high ) (16 ft x12 ft x10 ft high )

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SLIDE 12

J.S. Zhang, Syracuse University 4/9/2005 12

Thermal & Air Quality Research Facility Thermal & Air Quality Research Facility

  • Applications

Applications

  • Characterization of emission sources

Characterization of emission sources

  • Performance of air cleaning devices

Performance of air cleaning devices

  • Room air & contaminant distributions

Room air & contaminant distributions

  • Microenvironment modeling for exposure & health

Microenvironment modeling for exposure & health risk assessment risk assessment

  • Thermal and IAQ performance of wall & window

Thermal and IAQ performance of wall & window components/systems components/systems

  • Evaluation of HVAC control systems

Evaluation of HVAC control systems

  • Evaluation of IAQ sensors

Evaluation of IAQ sensors

  • Impact of outdoor climate on indoor environment

Impact of outdoor climate on indoor environment

  • ……

……