1 | WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM – December 2012 eere.energy.gov

Indoor Air QualityWEATHERIZATION ENERGY AUDITOR SINGLE FAMILY

WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM – December 2012

2 | WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM – December 2012 eere.energy.gov

By attending this session, participants will be able to:• Recognize about the factors affecting IAQ. • Describe the role moisture plays in IAQ. • Discuss moisture movement. • Formulate pollutant remediation techniques.• Examine the impact of occupant behavior on IAQ. • Describe the evolution of ventilation standards.• Describe the requirements of ASHRAE 62.2 2010.

Learning ObjectivesINDOOR AIR QUALITY

3 | WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM – December 2012 eere.energy.gov

• Moisture and Mold• Stored Toxic Materials• Carbon Monoxide (CO)• Radon• Sewer Gas• Other

IAQ and MoistureINDOOR AIR QUALITY

Photo courtesy of The PA WTC

4 | WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM – December 2012 eere.energy.gov

Occupant Driven IAQ Sources

• Common household pollution sourceso Pet dander

o Volatile Organic Compounds (VOC’s) Improperly stored solvent, paints, cleaners

o General unhygienic conditions

o Rodent or Insect Infestations

• Making things worseo Tight house with a lack of ventilation

o Uninformed occupantsPhoto courtesy of The US Department of Energy

INDOOR AIR QUALITY

5 | WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM – December 2012 eere.energy.gov

Sources of Water Vapor

Source Quarts per Day

Construction materials first year 40

Standing water in basement 30

Damp basement or crawlspace 25

Greenhouse connected to house 25

Humidifier - large 20

Drying 1 cord of firewood 16

Clothes dryer vented to inside 13

Respiration/perspiration – 4 people 4.7

Clothes washing 2.1

Unvented gas range 1.3

Cooking without lids 1.0

Houseplants – average number 0.5

Dish washing 0.5

Floor mopping 0.4

Showering/bathing 0.3

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Related to occupant behavior

Related to the building

6 | WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM – December 2012 eere.energy.gov

Moisture Movement

Diffusion Through Surface Convection Through Holes

Air molecules are blocked.

Water vapor molecules are passed.

Air flow

Both water vapor and air molecules pass through.

INDOOR AIR QUALITY

7 | WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM – December 2012 eere.energy.gov

Permeance of Building Materials

Permeance of Building MaterialsMaterial placed on the warm side of a building surface to retard diffusion of water vapor is called a vapor barrier. Material intended to retard convection is called an air barrier. Material which accomplishes both is termed an air/vapor barrier. A material qualifies as a vapor barrier if its permeance is 1.0 perm or less.

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8 | WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM – December 2012 eere.energy.gov

IAQ and Relative Humidity

Relative Humidity and Indoor Air Quality RelationshipsDecrease in bar width indicates decrease in effect

Bacteria

Viruses

Fungi

Dust Mites

Respiratory Infections

Allergic Rhinitis and Asthma

Clinical Interactions

Ozone Protection

Percent Relative Humidity 0% 10% 20% 30% 40% 50% 60% 70% 80% 90%

INDOOR AIR QUALITY

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What Determines IAQ?INDOOR AIR QUALITY

Photos courtesy of The US Department of Energy

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Client Interview

Use the interview process to learn more about how the client uses their home as it relates to health and safety:

• How many people live in the home?• Are there cold rooms? Hot rooms?• Do they use the fireplace or unvented space heaters?• Does anyone in the home have asthma or other illnesses?• Are headaches a chronic problem in the heating season?• Do they use their kitchen and bathroom exhaust fans?• Do they dry clothes or wood in the house?• Are there any unpleasant odors or burning sensations?

INDOOR AIR QUALITY

11 | WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM – December 2012 eere.energy.gov

• Properly size central AC units. • Talk people out of using unvented heaters.• Don’t overcool the house in summer.• Don’t hang wet clothes in the house.• Don’t dry wood indoors.• Use kitchen and bath exhaust fans.• Enhance room circulation with fans to avoid cold spots.

Client EducationINDOOR AIR QUALITY

12 | WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM – December 2012 eere.energy.gov

• Testing and abatement is not an allowable expense. (WPN 11-6 H&S Guidance)

• Mold clean-up is not an allowable expense• Correcting moisture problems that may cause mold is

allowableo Controlling surface temperatures with good

insulation and air sealing practiceso Venting dryerso Installing mechanical ventilationo Fixing minor drainage issues

What WAP Can and Cannot DoINDOOR AIR QUALITY

13 | WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM – December 2012 eere.energy.gov

Pollutant Action Tree

Source• Eliminate• Encapsulate• Dilute

Driving Force• Eliminate • Weaken

Path• Eliminate• Block

INDOOR AIR QUALITY

Photo courtesy of The US Department of Energy

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Outside Air and IAQ

How much outside air do we need for good IAQ?How do we get it?

Mechanical FansBuoyancyStack effect - warm air rising

Exhaust Fan

WIND DIRECTION

Wind

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How has natural ventilation been calculated?

N-factor variables:

• Geographic location

• Building height

• Building exposure

The n-factor for the house illustrated at right would be different if it was one story taller, or less shielded. The map shown below is the LBL Climate Zone Map used to determine the geographic variable.

INDOOR AIR QUALITY

16 | WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM – December 2012 eere.energy.gov

Why Isn’t the MVG Our Best Tool?

Photos courtesy of The US Department of Energy

The matched board ceiling above has many feet of linear cracks that expand and contract depending on relative humidity (RH).

The missing flue plug creates a stable-sized round hole with little air flow drag.

A single-point blower door test will see these holes as identical!

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Neutral pressure plane

Random Size & Distribution?INDOOR AIR QUALITY

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CFM50 = 4000

CFM50 = 2000

Desired ventilation = 75 CFM

CFM50 = 1000

CFM50 = 1000 + 75 CFM fan

050

100

150

200

250

Ventila

tion Rate, C

FM

0 20 40 60 80 100

Outdoor Temperature, degrees F

Based on single-story 1,500ft2 house

Chart courtesy of Paul Francisco

An Important Corollary!

INDOOR AIR QUALITY

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ASHRAE 62.2-2010

www.ashrae.org

What is the DOE Requirement Now?

A Wisconsin pilot study conducted in 2004 found that 78% of weatherized units required additional mechanical ventilation under 62.2, up from 47% using the previous ASHRAE standard, 62.1989.

Average installed cost, including controls: $525 (2004-2005 prices).

INDOOR AIR QUALITY

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ASHRAE 62.2-2010

Photos courtesy of The US Department of Energy

INDOOR AIR QUALITY

21 | WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM – December 2012 eere.energy.gov

Floor Area (ft2)

BEDROOMS

0 - 1 2 - 3 4 - 5 6 - 7 >7

< 1500 30 45 60 75 90

1501 – 3000 45 60 75 90 105

3001 – 4500 60 75 90 105 120

4501 – 6000 75 90 105 120 135

6001 – 7500 90 105 120 135 150

> 7500 105 120 135 150 165

Table 4.1a: Minimum Ventilation Air Requirements, CFM, New Buildings1

1 ASHRAE 62.2-2010, p 4

ASHRAE 62.2-2010 Table

45

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22 | WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM – December 2012 eere.energy.gov

· Assumes two occupants in master bedroom and one each in the other bedrooms. Over this density, increase ventilation by 7.5 cfm/person.

· Whole building, intermittently operating ventilation may be used under some conditions for compliance.

· Ventilation air must come directly from the outdoors.

· Credit is allowed for envelope air leakage in some cases, based on ASHRAE 62.2 and 136.

CFMfan = 0.01Afloor + 7.5(Numberbedroom + 1) + (alternative compliance supplement)

- (Infiltration credit)

A = conditioned floor area; “the part of the building that is capable of beingthermally conditioned for the comfort of occupants.” (ASHRAE 62.2, p.3)

2 Slide content from ASHRAE 62.2-2010

ASHRAE 62.2-2010 Formula

New or Existing Buildings2:

INDOOR AIR QUALITY

23 | WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM – December 2012 eere.energy.gov

Beyond Fan CFM Requirements

ASHRAE 62.2 2010 includes:

• Spot ventilation requirements as mentioned.

• Attached garages must be adequately sealed from living space to prevent migration of contaminants.

• Clothes dryers must be vented to exterior.

• All duct joints outside conditioned space must be sealed.• Sone rating requirements must be met.

• Branch duct systems must have backdraft dampers.

• Whole-home fan flow must be verified.

• Continuous vs. intermittent fan specifications.Photo courtesy of The US Department of Energy

INDOOR AIR QUALITY

24 | WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM – December 2012 eere.energy.gov

Summary

• IAQ depends on the pollutant source strength and the air change rate. Elimination at the source is preferable to confinement, which is preferable to dilution.

• Many pollutants are present in the average home: The air change rate is a function of inside to outside pressure difference, hole size, and hole location.

• A higher air change rate equals better IAQ, and usually higher space conditioning costs.

• ASHRAE 62.2 2010 guidelines are a required standard for new and existing buildings.

• Occupant behavior can have a major impact on IAQ.

INDOOR AIR QUALITY