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Chapter 5 Airf low 5 - 1

Airflow

AIRFLOW

Weatherization Assistance ProgramIndiana Field Guide

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5 - 2 Indiana Wx Field Guide

Airflow

AIRFLOW

STANDARD - AIRFLOW

Controlling airflow for Weatherization requires establishing astrategy that reduces infiltration, yet ensures safe,healthful and efficient operation of the building andthe systems within the building.

Procedure - Airflow

Establish a site specific minimum ventilation rate(MVR) and express in CFM 50.

Determine pre-weatherization airflow rates usingBlower Door and express in CFM 50.

If structure is below the MVR, determine if addingmechanical ventilation is appropriate.

If structure is below the MVR, airsealing should onlybe completed where bulk moisture could be deliveredto the attic.

Perform site specific diagnostics. Perform Blower Door assisted, cost-effective air

sealing. Do not airseal below the established MVR.Concentrate efforts on major air leakage such as atticleakage sites, duct systems, interstitial connections,and obvious large holes.

Determine post-weatherization airflow rates.

Conduct post inspection and detailed health andsafety tests including DSTO.

Perform client education as needed.

STANDARD - SITE SPECIFIC AIRFLOW

A site specific airflow standard shall be established for

every unit slated to receive weatherization. This standard isthe minimum ventilation rate (MVR) as measured by blowerdoor testing. It is determined by selecting one of thefollowing three methods, whichever provides thehighestairflow rate:

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Use the larger of the above four as your airflow standard.

Procedure - Determine MVR

1200 CFM@50 Pa is the baseline MVR.

A whole building air change per hour (ACH) rate not less than .35ACH (.4 ACH if building volume is used for combustion air)

converted to CFM 50.

An occupancy rate of not less than 15 CFM per personconverted to CFM 50. Occupancy is generally considered to benumber of bedrooms plus one. Use actual number of persons ifhigher than number of bedrooms plus one.

Converting from CFM 50 to CFM Natural depends on several factors

including climate, building height and wind shielding. Climate factorsdiffer somewhat across Indiana. The following is an average for Indianain determining natural infiltration rates:

CFM 50 N = CFM Natural

One Story House: N = 23 CFM 50 23 = CFM Nat

Two Story House: N = 18.5 CFM 50 18.5 = CFM Nat

Three Story House: N = 16 CFM 50 16 = CFM Nat

Site Specific Airflow Standards

1. Baseline MVR Standard

2. .35 ACH (or .4 ACH)building volume aiflow standard

3. 15 CFM per personoccupant airflow standard

=1200CFM 50

=House Volume (cu. ft.) x .35 = cu. ft.per hour

cu. ft. hour 60 = CFM Natural

CFM Nat x N =CFM 50

=Bedrooms + 1 orActual #of persons = Occupancy

Occupancy x 15 CFM per person =CFM Nat

CFM Nat x N =CFM 50

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VENTILATION

STANDARD - VENTILATION

Building performance retrofit strategies may include amechanical ventilation to protect the building and theoccupants in the case of an excessively tight building.Ventilation strategies should protect the occupants health andsafety while at the same time enabling optimization of buildingthermal performance. Adding ventilation shall not be asubstitute for source control of pollutants - i.e. moisture, CO,etc.

STANDARD - MECHANICAL VENTILATION

Mechanical ventilation should be used where force is needed totemporarily exhaust pollutants from the building.

It is the active process of supplying or removing air from anindoor space by powered equipment.

There is no fail-safe solution that can assure good indoor airquality. It will require proper building operation and goodbuilding maintenance.

The change to mechanical ventilation eliminates long periods ofthe year where houses are under-ventilated if infiltration is theonly source of ventilation.

Procedure - Mechanical Ventilation Use bathroom exhaust fans to exhaust moisture.

Use kitchen range hoods to exhaust moisture andcombustion products while oven/stove is in use.

Consider sealed combustion appliances to prevent CAZdepressurization problems or to overcome poor draftconditions. Installing power vent kits may be an option as

well on existing units. Consult manufacturers literaturebefore making modifications.

Consider installing continuous rated mechanicalventilation fans in buildings which are tighter than thecalculated minimum ventilation rate (MVR) or haveunacceptable indoor air quality, especially whereinfiltration is the only source of ventilation.

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Exhaust Fans

Insulate exhaust

ducts inunconditioned

space

Kitchen and bathroom exhaust fans provide ventilation where it isneeded.

Sealed-Combustion Heater

Exhaust gases

Combustion air

Sealed-combustion heaters are less affected by depressurization andcan reduce the need for ventilation.

Size fan and select operating speeds that reflectinfiltration and mechanical ventilation interaction.Choose a control appropriate for a specific building andclient.

Perform client education.

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STANDARD - VENTILATION SAFETY

Anytime a ventilation system is installed in a building, aworst case CAZ depressurization test shall be conducted.(see Health & Safety chapter)

Procedure - Ventilation Installation

Always follow the manufacturers installationinstructions.

Operation instructions should be posted in thevicinity of the installation to avoid occupant overrideor misuse.

Occupants shall be instructed in the use andmaintenance of installed ventilation equipment.

Vented air must be exhausted totally outside of thebuilding.

Exhaust connects should be properly pitched toavoid condensate buildup.

Exhaust connects should be insulated where passing

through cold areas to avoid condensation.

All intake and exhaust openings should be screenedto prevent foreign objects from entering.

Electrical wiring used to install ventilation equipmentwill comply fully with current electrical codes.

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Ventilation System Using Existing Exhaust

Fans

Automatic cycling or continuous operation along with passive ventsmakes standard exhaust fans into a ventilation system.

Central Ventilation System with Ducts

Vent ducts running through unconditioned spaces should be insulated.

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STANDARD - LOW AIRFLOW HOUSING

When actual pre-retrofit airflow rates are lower than theestablished airflow standard for the building, furtherevaluation must be done to ensure that indoor air quality isnot jeopardized. If post-retrofit airflow is measured below theminimum ventilation rate (MVR), mechanical ventilationis recommended.

Procedure - Low Airflow Housing

Check for obvious sources of moisture.

Check building for signs of moisture degradation.

Determine if the occupants complain or showsymptoms of building-related illnesses such as upperrespiratory problems.

If conventional (atmospheric) combustion appliancesare in use in the building, perform worst casebackdrafting test. (See Health and Safety Chapter)

If combustion appliances are present in the living

space, consider building walls to partition off a CAZ. Check for smokers living in the building. Encourage

outdoor smoking or ventilation of designated smokingrooms.

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Sources of Indoor Air Contaminants

1. Auto exhaust, chemicals stored in garage.

2. Combustion appliance by-products.

3. Smoke, food odors, moisture.

4. Particulates from solid fuel.

5. Moisture; chemicals.

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Issues To Be Resolved Before Airsealing

Mold, mildewand dry rot

Poorappliance

draft

InsectInfestation

CombustionAppliance

Zone SafetyTests

Depressurizationfrom mechanicalexhaust devices

Unventedcombustionappliances

Combustionappliance zonedepressurization

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MEASURING AIRFLOW

STANDARD - CFM 50 TEST

A single point blower door test will be conducted on all unitsat the original building analysis and at the post inspectionto quantify airflow, as well as during the retrofit to determinethe cost effectiveness of air sealing.

Procedure - Blower Door Testing

Conduct initial health and safety inspection (Seepage 5-2).

Configure the unit in winter modewindows, exteriordoors, vents closed, all air registers open.

Conduct a building survey and determine the thermalboundary.

Identify and repair large problem areas that wouldhamper blower door test (i.e. - missing window, holein ceiling).

Ensure that all combustion appliances are turned off. Turn off all exhaust systems.

Pressure relieve any suspended ceilings.

Open all interior doors within the thermal boundary ofthe house.

Close all solid fuel appliance dampers.

Select an appropriate exterior doorway and installblower door.

Assure that children and pets remain clear of the fanoperation area at all times.

Perform blower door test.(Refer to Blower DoorManufacturers manual for specifics.)

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Procedure - Blower Door Depressurization Test

Install blower door frame, shroud, and fan in exteriordoorway. The fan is calibrated in one direction only.Position the fan with the air inlet inside, flow direction

out. Install manometers as illustrated. Keep hose

measuring outdoor pressure away from the influenceof the fan action.

Calibrate (zero) pressure gauges.

If using the DG-3 or DG-700 digital gauge, measurebaseline pressure difference and consider that when

calculating 50 pascal pressure difference. Activate fan and record corresponding house and fan

pressures/CFM flow.

Make sure combustion appliances are operationalwhen Blower Door testing is completed.

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Blower Door Depressurization

Blower door depressurization isthe most common type of air

leakage test for a home.

Channel A measures negativepressure during blower door

depressurization.

Channel B measures airflow

through the blower doors fan.

Ensure negative

fan WRT house

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Procedure - Blower Door Pressurization Test

Choose a pressurization test when fireplace or woodstove has been in use or when testing mobile homeswith loose fitting jalousie windows without interior

storms. Note: Use extreme caution in this mode. Install blower door frame, shroud, and fan in exterior

doorway. The fan is calibrated in one direction only.Position the fan with the air inlet outside, flowdirection in.

Install manometer measuring indoor pressure WRToutdoor pressure.

Install manometer measuring outdoor pressure WRTfan pressure.

Calibrate magnahelic type gauges.

Activate fan and record corresponding house and fanpressures.

Make sure combustion appliances are operationalwhen Blower Door testing is completed.

STANDARD - BLOWER DOOR TEST POORIAQ

Blower door testing should be suspended if it is determinedthat harmful pollutants will be introduced into the livingspace by the operation of the blower door. In thesecircumstances switching to a pressurization test oftenmitigates these concerns.

STANDARD - BLOWER DOOR TEST LARGEBUILDINGS

Blower door tests shall be conducted on all buildings withinternal volumes up to 60,000 ft3. Conduct one blower doortest of the whole building, if possible. More than one blowerdoor can be utilized at the same time for the testing of large

buildings or buildings with zones that cannot be opened toa common doorway. If more than one test is required toevaluate the whole building, then configure the building toaccomplish this evaluation using as few blower doors aspossible.

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Blower Door Pressurization

Analog manometers measurehouse pressure and airflow during

blower door pressurization.

Channel A measures a positivepressure during blower door

pressurization.

Channel B measures airflowthrough the blower doors fan.

house WRT

outdoors

fan WRT outdoors

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Procedure - Testing With Multiple Blower Doors

Set up blower doors in zones selected to test theentire internal volume.

Set blower doors to the same mode

depressurization/pressurization.

Coordinate pressures established WRT outdoors ofboth blower doors before recording data points.

Conduct standard single point test.

Add the flow rates of the tests at 50 Pascals for awhole building flow rate.

STANDARD - BLOWER DOOR ASSISTEDAIRSEALING

All airsealing work will be blower door assisted. Beforecommencing airsealing activities conduct a generalinvestigation utilizing the blower door.

Procedure - Blower Door Assisted Airsealing Segregate conditioned area of the house from

surrounding zones by closing doors to the attics,cellars, garages or storage areas.

Depressurize main body of the house to -50 Pa.

Survey room by room for indications of air leakage.

Investigate connections between main body of house

and surrounding zones.

Establish strategies to airseal these connections.

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STANDARD - COST EFFECTIVE AIRSEALING

The most cost effective airsealing involves addressing thelargest leakage paths first. Confirm effectiveness ofairsealing strategies using interim blower door tests.Always conduct a daily safety test out following air sealingwork.Airsealing activities begin in General Heat Waste Reductionmeasure in both Waiver Audit Priority lists and arecategorized as major. Activities include:

Duct sealing,

Interstitial connection sealing, and

Major holes located high and low in the building.Minor air sealing, such as caulk and weatherstripping,should be kept to a minimum and performed only aftermajor air sealing is finished and house remains above theMVR. Minor air sealing should be Blower Door assistedand should stop when no longer cost effective.

Procedure - Sidewall Insulation

Install high density insulation to exterior wall cavitiesand band joist areas between floors.

Conduct blower door test and record results.

Verify that vented appliances draft properly (DSTO).

Procedure - Att ic Airsealing - Open Att ics

Depressurize conditioned area of building with theBlower Door.

From within the attic, locate leakage from the livingspace and other zones with diagnostic smoke andpressure differentials. Infrared scanning may behelpful ift permits and Blower Door is switched toPressurization mode.

Specifically check for leakage along exterior wallconnects, interior wall top plates, around chimneys,interior vent penetrations, around plumbing ventpipes, at electrical penetrations and interstitialframing areas, i.e. stairways and attic hatches.

Airseal identified bypasses with appropriatematerials.

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Inspect attics for bypasses and airseal before insulating.Ensure proper clearance to combustible materials.

Aroundchimneys Plumbing

penetrations

Recessed

lights

Aroundhatches

Electricalpenetrations

Seal ducts andductwork penetrations

Open wallcavities

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Procedure - Att ic Airsealing - Floored Attics

Drill test holes over interior wall framing and probe forproper wall cap. If no cap exists, consider drilling theattic floored deck the length of interior walls and

tubing the interior walls with high density cellulose. Pull a selection of floor boards over interior walls if

possible. This will give better visibility to issues offraming technique, electrical wiring condition, orleakage paths.

Airseal as many large leaks as practical.

Install high density cellulose insulation between the

floor and ceiling, never on top of the floor.

Procedure - Interstitial Connection Airsealing

J oists between floors - airseal around perimeter ofbuilding at band joist areas with high densityinsulation or apply spray foam.

Interior wall framing - airseal all interior walls to attic.

This must be done before additional attic insulation isinstalled. If attic insulation already exists remove itfrom the area directly over the wall to properly identifyproblems and facilitate repairs. Walls with no cap orplate can easily be dense packed or capped withHigh-R board, wood, metal, and foam sealants, etc.(In compliance with National Fire PreventionAssociation) to tightly seal them off.

Framed ventilator, laundry, dumbwaiter shafts canconnect several levels of the house from cellar toattic. Locate and seal top and bottom of shaft. Sealat each floor level if appropriate.

Locate and seal framing around chimneys with firerated materials at the penetration through the atticfloor and at the lowest level of framing around thechimney. (Usually the cellar ceiling).

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Poly encases fiberglass to restrict airflow.Foam around edges to finish sealing process.

Wood, sheetrock, foam, metal are all alternative blockingmaterials to use.

Sealing Interior Wall Framing

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Procedure - Duct Repair

Perform initial Pressure Pan test and prioritize ductsealing activities.

Replace any deteriorated or missing ductwork.

Evaluate where the building framing may be used asductwork and repair as necessary.

Ductwork can be found in basement, crawl spaceand attics.

Secure ductwork at connections with metal screwsand support long sections with hanger strap.

Starting at the air handler and moving towards theregisters, repair air leakage with latex based mastic.Use butyl backed tape and sheet metal patchesunder mastic as needed. Be sure to address the airhandler cabinet as well as the ductwork.

Perform a temperature rise test after duct repair hasbeen completed to ensure adequate airflow.

Perform follow up Pressure Pan test and re-prioritize

remaining leakage.

Always perform Daily Safety Test Out following anyduct repair activities.

Procedure - Basement Airsealing

Airseal large gaps in foundation.

Airseal electrical and plumbing penetrations.

Airseal around chimney with fire rated materials. Airseal bottom of open walls (balloon framing) and

other open framing connections.

Conduct comprehensive health and safety evaluation.

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Airsealing a Panned Floor Joist

Seal all joints in this area

Seal between sheet

metal and joist

Panned floor joists leak through the many cracks and seamswithin the framed cavity. They are best sealed on their interior surfaces

with the sheet metal removed.

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DIAGNOSTICS FOR FORCED AIR

DISTRIBUTION SYSTEMS

STANDARD - FORCED AIR DISTRIBUTION

When a forced air distribution system is present and anypart of that system is located outside the homesconditioned space, diagnostics shall be utilized to locateand quantify duct leakage. CAZ depressurization testingwill be used to verify that duct leakage does not exertnegative pressure on combustion appliance zones.Pressure pan testing will be used to locate leakage and

verify its reduction to acceptable limits.

Procedure - Pressure Pan Duct Leakage Test

1. Put the house in winter conditions.

2. Make sure all supply registers and return grilles areopen.

3. Pressure relieve the space the ducts are in.

4. Depressurize the house to -50 Pa or maximumpossible.

5. Verify that duct zone is pressure relieved by gettinghouse to duct zone pressure reading. Ideally readingwill be within 5 pascals of house to outside pressurereading.

6. Place a pressure pan over each register and grille,one at a time, and record the pressure reading withreference to the house from a digital pressuredifferential gauge.

7. If covering a grille with duct mask to probe forreading, remove duct mask before proceeding to nextgrille or register.

8. Duct sealing should continue until pressure panreadings are below 1 Pa. Prioritize from highest to

lowest reading. Re-test with pressure pan to validateresults. A final reading of 3 Pa can be acceptable ifreasonable effort has been made to seal a duct withdifficult access.

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Insignificant Leak

Significant Leak

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Procedure - Mobile Home Diagnostic SmokeLeak Location Test

Locating duct leakage can be simplified, as in mobilehomes where access to the duct is hindered by the belly

board and insulation.

Set up the home in the winter mode.

Install blower door and put slight positive pressure onthe living space; 5 - 10 Pa.

Starting at one end of the supply trunk, puffdiagnostic smoke into the register. The smoke willflow in the direction of the predominate leak.

Move to the next register in line and repeat thesmoke test. If the smoke now moves in the oppositedirection, then the predominate leak has beenisolated to between these two points.

Verify that leaks are or are not associated with thefurnace-to-base, and the base-to-trunk connection, byperforming this procedure at the registers directly on

either side of the furnace.

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Duct leaks in mobile homes are easily located using diagnostic smokein a pressurized environment.

Mobile Home Duct Leak Test

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Procedure - Temperature Rise Test

Airseal supply and return duct system.

Operate furnace and allow it to reach steady-state.

Measure temperature of supply air and return air. If the temperature difference remains within the

recommended temperature rise stated on furnaceinformation tag, throughout a continuous cycle, thesystem is moving enough air for reasonable heattransfer from exchanger to distribution.

If the temperature difference increases beyondmanufacturers temp rise range or burner is shut

down by high limit shut off, the heat transfer fromexchanger to distribution is inadequate. If noinformation from a manufacturers tag is available,use 160 F as a rule of thumb for maximum supplyair temperature. Generally the temperature riseshould be between 40 - 70 F.

Consider for repairs:

Possible inadequate supply ducts Possible supply restriction

Possible inadequate return ducts

Possible return restriction

Adjusting distribution fan for more flow

Over fired combustion

Clean distribution fan vanes and filters

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Temperature Rise Test

Test supply air

temperature here

Test return airtemperature here

Temperature should be taken out of direct line from the heat exchanger.This will minimize high readings due to radiant energy.

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STANDARD - BALANCING DISTRIBUTION

When a forced air distribution system is present, stepsmay be required to insure that no parts of the house arestrongly pressurized or depressurized when the air handleris turned on. The pressure to the outside should not changewhen interior doors are opened or closed. Negativepressure must be controlled in any zone containing naturalor induced draft combustion appliances in any climate, andavoided in buildings in humid cooling climates. Above gradepositive pressure due to air handler operation is to becontrolled in heating climate buildings with normal or highinterior moisture levels. Pressure balancing must be

considered whenever there is a change in pressure greaterthan 2 Pascals with reference to the outside. Delivery andreturn of conditioned air must be adequate to maintaincomfort and air quality in all occupied rooms. Since bothhouse tightness and distribution system flows affect thefinal pressure, pressure balancing and worst-case safetytesting should be performed after airsealing, insulation andduct sealing is complete.

Note: The prevention of durability and safety problems mayrequire additional work or more complete pressure control,and is beyond the scope of this guide. The 2 Pascal limit isbased on current common measurement technology, not onthe specific needs or risks in a given building.

Procedure - Pressure Balancing Tests

Verify the filter is clean or removed, the registers areopen and not obstructed, and both the A-coil and airhandler fan are clear of accumulated dust and debris.

Set up closed house conditions, with all exteriordoors and windows closed and all equipment off.Open the interior doors. Record the baseline pressurefrom the main body of house to outside.

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Activate airhandler fan, measure change in pressurefrom base condition, record as dominant duct test. Apositive change in pressure indicates more returnleakage from the exterior, and a negative indicatesrelatively more supply leakage to the outside. Thisindicates incomplete duct sealing work, or anintentional opening such as a fresh air intake cut intothe return.

Close all interior doors, activate air handler fan,measure main body to outside pressure change frombase condition, and record. Measure each room tomain body pressure, record.

Pressure balancing must be considered wheneverthere is a change in pressure greater than 2 Pascalswith reference to the outside.

Perform combustion appliance zone depressurizationand worst case draft test after any modifications.

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STANDARD - PRESSURE BALANCINGROOMS

Often with forced air distribution the main body of the housecontains the only return air grilles while areas such asbathrooms and bedroom have only supply registers. In theevent that the doors to such rooms are closed during theoperation of the distribution system, the main body is likelyto experience negative pressure while the individual roomswill experience positive pressure. Pressure balancing mustbe considered whenever there is a change in pressuregreater than 2 Pascals with reference to the main body.

Procedure - Techniques for Pressure BalancingRooms

With distribution fan running establish manometerreading room pressure WRT main body pressure.

To estimate the balancing effect of door undercut,open each door 1/4 to 1/3 inches to duplicate the freeair opening of a 3/4 to 1. Undercut on the door.

Measure the new pressure and record if acceptable. Undercutting the door is seldom adequate. Open the

door 3/4 to 1 to duplicate the effect of a 10 x 14transfer grille. Measure the new pressure and recordif acceptable.

Undercutting the door and adding a 10 x 14 transfergrille may be adequate.

If further reduction is required, a return may be thebest option.

To estimate required flow in CFM or free air inches ofa larger transfer grille, open the door until thepressure across the door drops to 1 Pascal andmeasure the size of the opening in square inches.

Perform CAZ depressurization test and worst casedraft test. (See Health & Safety chapter.)

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Pressurized Bedroom

Large positive pressures in an individual room with a closed door anddistribution fan running is caused by the inability of air to return to the

central return grille.

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ZONAL PRESSURE DIAGNOSTICS

STANDARD - AIRFLOW DIAGNOSTICS

After major air sealing measures have been completed,pressure diagnostics can be used to evaluate the pressureboundary between the main body of the house and attachedzones such as basements and attics. This information canhelp crews determine whether they have effectively isolatedthem or if further air sealing is in order.

Procedure - Basement Zone PressureDifferential Measurement

Install manometer reading basement pressure WRToutdoor pressure.

Close doors to all zones outside of main body ofhouse. This includes basements, attics, garages andstorage areas.

Bring main body of house to -50 Pa with the blowerdoor.

Note and record manometer reading of basementWRT outdoors.

Results - low pressure difference indicates:

The floor of the main body of the house is the moreeffective air barrier or

The basement to outdoors is leakier than thebasement to house or the effective leakage betweenhouse and the basement is less than effectiveleakage from basement to outdoors.

Results - high pressures (above 25 Pa) indicate that thebasement sidewalls are serving as the effective air barrier

and that the leakage between the house and basement isgreater than leakage between basement and outdoors.

Note visual leakage from outdoors to basement for relativeinterpretation of this information.

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Basement Zone Pressure Testing

-33

Pressure testing the basement zone tells the relative air tightness of thefloor versus the foundation walls.

( P) x (A) x (1.06) = CFM

when A = square inches of opening and P = pressure. 1.06 = constant.

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Procedure - Attic Zone Pressure DifferentialMeasurement

Install manometer - attic pressure WRT outdoorpressure.

Close doors to all zones outside the main body ofhouse. This include basements, attics, garages andstorage areas.

Depressurize main body of house to -50 Pa withblower door.

Note and record manometer reading to attic.

Results - no or low pressure difference means: the ceiling ofthe main body of the house is the more effective air barrieror the attic to outdoors is leakier than the attic to house orthe leakage between the house and the attic is less thanleakage from attic to outdoors.

Results - high pressures (above 35 Pa) indicates that theattic roof is serving as the air barrier and that the leakage

between the house and attic is greater than leakagebetween the attic and outdoors.

Consideration - if you can approximate the size hole orcollection of all holes from the outside to this zone insquare inches, then applying P x A x 1.06 will indicate therelative leakage from this zone to the house.

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Attic Zone Pressure Testing

Measuring the pressure difference between the attic and outdoorsduring a blower door test helps evaluate the ceilings airtightness.

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Procedure - Att ic to Basement CommunicationPressure Differential Measurement

Install manometer reading attic pressure WRToutdoor pressure.

Close doors to all zones from main body of house,including basement, attic and garage.

Depressurize main body of house to 50 Pa WRToutdoors.

Note attic pressure WRT outdoor pressure.

Open door to basement to include it in the test area.Re-set blower door to -50 Pa.

Record pressures created in attic WRT outdoors.

Results - If negative pressures within the attic increase fromthose noted in the attic WRT outdoors test, then bypassesfrom the basement to the attic are indicated. A modificationof this test can indicate if side attics communicate.

Procedure - Quantify ing Leakage - Add a HoleDifferential Pressure Measurement Test

Bring main body of house to 50 Pa and note CFMflow.

Record pressure of attic WRT outdoors.

If attic pressure WRT outdoor pressure is below 15Pa while maintaining 50 Pa on the house, slide open

the attic hatch until the attic pressure WRT outdoorpressure doubles. (If the attic pressure is above 15Pa in this configuration, ceiling leaks should be easyto locate.) Record CFM 50 Pa flow rate. (Example: -4 Pa increasing to -8 Pa). Note opening size, as thisrepresents the equivalent leakage area: between atticand house.

The increase in the CFM 50 Pa flow rate represents

approximate leakage between attic and house.

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Add - a - Hole Test

Using the attic hatch to add a hole to the ceiling during a blower doortest helps estimate leakage area.

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Procedure - Zone Pressure Diagnostics (ZPD)Calculation Utility

In 2000, the Chicago Regional office of the Department ofEnergy (DOE) sponsored a study of ZPD techniques and

procedures with the goal of improving the accuracy,reliability and user friendliness of zone leakage estimates.The results of that study, published in 2002, includenumerous improvements to the ZPD collection methodsand air leakage calculation procedures. In response to thestudy findings, The Energy Conservatory (TEC) developed aZPD Calculation Utility. The Utility is a simple softwareprogram which can be used to quickly perform ZPD

calculations using many of the improvementsrecommended in DOEs study. The ZPD Calculation Utilityassumes that the Blower Door test results and zonepressure measurements are being collected using aMinneapolis Blower Door and digital gauge both of whichare in use at every Weatherization program in Indiana. TheZPD Calculation Utility is available free of charge from TheEnergy Conservatory website atwww.energyconservatory.com/zpd.html. The Utilityrepresents a welcome refinement of the previouslycumbersome ZPD procedure; we recommend it to IndianaWeatherization program crews and auditors.

Procedure - Attached Porch Att ic PressureDifferential Measurement

Install manometer reading roof cavity pressure WRT

outdoor pressure.

Depressurize main body of house to -50 Pa withblower door.

Note and record manometer response.

Note visual leakage from outdoors to cavity forrelative interpretation of test results.

It is always best to visually inspect the house wall

inside these spaces and not rely on pressure testingalone.

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Measuring for depressurization of an attached porch attic.

Many porch roofs do not havesheathing here. This area can hide

a major conduit for air leakage.

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AIRSEALING ECONOMICS

Cost Effective Airsealing - refers to the energy saved overthe lifetime of the materials installed in relation to the cost

of installing them.

All of the previously mentioned air sealing procedures willmost likely be performed in a high priority within our waiveraudit protocol (furnace repair and efficiency, duct sealing ormajor air/bypass sealing) and have a high and long-lastingimpact.

However, additional air sealing may be beneficial if it isfound to be cost effective. The last priority in our waiveraudit protocol is Minor Air Sealing. It should be performedwhen appropriate and only if the measures installed arecost effective.

FSSAs intention is that airsealing crews will proceed withMinor Air Sealing using the blower door both as adiagnostic tool and a device to measure the crews relative

effectiveness.

Procedure - Performing Cost-Effective Minor AirSealing

Perform blower door CFM 50 test and record reading.Stop if you have reached MVR for this building.

Do not seal lower level leaks in the building until you

have first addressed leaks in the top part of thehouse, especially the ceiling.

Concentrate on the largest leaks first before airsealing small cracks and penetrations.

While performing minor air sealing, take periodicblower door readings to measure the effectiveness ofyour efforts.

Based on the cost of the materials and the cost oflabor to install those materials, establish a cost limitper 100 CFM 50 reduction measured by the blowerdoor as minor air sealing continues. Also take intoaccount the cost of heating fuel. The higher the costfor fuel, the higher the acceptable cost per 100 CFM50.

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Use manometers to test attic and crawl/basement areas WRTmain body to assess relative connections to those areas.

Air seal the building in relatively small increments of time, re-testing with the blower door. Continue until the MVR is reached,

or you are no longer getting CFM reduction, or the cost of sealingexceeds your limit.

Document what you are doing, the materials used and thejustification for either continuing or stopping.

Take a final CFM 50 reading.

Always perform a Daily Safety Test Out on combustion appliancesonce finished air sealing.

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EVALUATION/POST INSPECTION

STANDARD - POST INSPECTION

All completed airsealing work shall be evaluated for itseffectiveness and its impacts on the buildings operation asa system.

Procedure - Post Inspection

1) Configure house to winter mode and perform singlepoint blower door test. Record results.

2) Perform final pressure pan test to validate numbers.

3) Perform heating systems final inspection and recordfindings in inspectors column.

STANDARD - OCCUPANT REVIEW(WEATHERIZATION CLIENT EDUCATION)

Following successful completion and evaluation of the

airsealing/ventilation work, the results shall be reviewed withthe building owner/occupants.

Procedure - Occupant Review

Review the results of the airsealing efforts explainingwhat responsibilities the occupants have inmaintaining a safe, healthy indoor environment.

Review general house operating instructions,showing locations of ventilation controls, HVAC airfilters and maintenance schedules/procedures.

Discuss the control of moisture build-up.

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Discuss the importance of not using unventedappliances for space heating.

Demonstrate procedures for performing a rudimentarydraft test showing occupant how to identify spillage

and CO indicators. Review manufacturers literature of equipment

installed.

Review maintenance schedules for mechanicalsystems.

Discuss smoking issues within airsealed houses.

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Notes

Documents

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