179685007 Blower Door Basics PDF

8/13/2019 179685007 Blower Door Basics PDF

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Housekeeping

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Agenda

Overview of house leakage basics and BlowerDoor equipment.

Setting up the Blower Door for consistent andaccurate test results. Explore how to do a test and how to use adigital gauge to perform the test.


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Hidden Construction Details

Often the largest and most important air leaks


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Hidden Construction Details


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Duct Leakage

In some homes, this is the highest priority(particularly in the sun belt)


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Purposes of a Blower Door Test

Document the relative airtightness of houses (arethey leaky - tight - or somewhere in between).

Help find air leaks by inducing air to move throughall leaks at the same time (chemical smoke, IRcamera, feeling with you hand, zonal pressures).


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Purposes of a Blower Door Test

Determine the effectiveness of airsealingactivities (compare before and after

measurements).

Investigate duct leakage problems.

Help estimate the need for mechanicalventilation.


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Blower Door Test

Supply

Return

BlowerDoorFan

Crawlspace

Attic

-50-50

Blower Door fan is used to blow air out of (or into)the house.

Adjust fan until the house pressure is changed by

50 Pa. (Approx. pressure of 20 mph wind)

Flow through the fan

needed to createa 50 Pa changeis the house

airtightness CFM50.


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Blower Door Test

CFM50 is really a measure of the total equivalenthole size.

ACH50 is used to adjust for house size-


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Blower Door Equipment

Adjustable aluminum frame and nylon panel.

Calibrated

Fan with two

Flow Rings

(A and B).

Accessory

case with

gauge,tubing and

manual.


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Blower Door Fan Basics

Airflow is determined bymeasuring flow sensorpressure (with reference to

upstream of fan).

Airflow can only be

measured in one direction(from inlet to exhaust).

On older fans motor wasreversible for diagnosticpurposes only.

flow

sensor


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Blower Door Fan Basics (contd)

Flow Rings are neededwhen measuring flowsbelow 2,400 CFM

(tight houses).

Failure to use Flow Ringscan lead to large errors.

Gauges will indicate whenFlow Rings should beused.

Fan Configuration Flow Range (cfm) for Model 3 Fan

Open (no Flow Ring) 6,300 - 2,400Ring A 3,000 - 900

Ring B 1,000 - 300


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Blower Door Placement

Try to install in exterior door of a large openroom. Avoid installing the fan where there arestairways or major obstructions to air flow very

close to the fan.

If the fan is installed next to a stairway or major

obstruction, use one of the Flow Rings ifpossible.

Always open the inside door and outside stormdoor as much as possible to prevent airflowrestrictions to the fan.


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Blower Door Placement

Place the outside pressure tubing away fromfan flow.

Outside pressure tubing shouldbe placed away from fan exhaust.


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Blower Door Frame

Adjust the aluminum frameto the width of the door.

Adjust the frame to theheight of the door.

Remove frame from the

door and place fabricaround frame (secure withvelcro).

Place in door and tightencam levers.


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Install the Fan in the Panel

Fan is installed in the fabricpanel and is supported bythe frame cross bar.

Nylon panel makes tightseal around the fan.

Typically installed with inletside of fan (Flow Rings)

inside the house depressurization test.


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Install the Fan in the Panel

For pressurization test, the fan must blow airinto the house (fan guard facing in).


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DG-700 Pressure and Flow Gauge

Gauge measuresdifferential pressures.

Used to simultaneouslymeasure the change inhouse pressure, and the

air flow through theBlower Door fan.

Proper tubing

connections and gaugesettings critical.


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Tubing Connections

Channel A used to measurehouse pressure.

Channel B used to measure fanflow.

Depressurization test

configuration shown.

Channel A Reference tap isconnected to outside (housepressure).

Channel B Input tap isconnected to fan (fan flow).


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DG-700 Pressure and Flow Gauge

Simultaneous display of house pressure and fanflow.

Fan and Flow Ring configuration are shown

directly on the display.

Channel A (left side) is connected to outside tomeasure change in house pressure.

Channel B (right side) is connected to fan tomeasure fan flow.


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Other DG-700 Features

Additional Test Features:

BASELINE feature can also be used forcombustion safety testing (worst case

depressurization).

Change in Building

Pressure From

Turning On an

Exhaust Fan (Pa)

-1

-2

-5

-6

0

-7

(Fan Off)

-2.6

-7.8

(Fan On)

-5.2

(Change)


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-1

-2

-3

-4

-5

-6

0

-7

(Fan Off)

-2.6

(Fan Off) - Measuring Baseline Pressur

(Fan Off) - Baseline Adjusted Pressure

-7.8

(Fan On)

-5.2

(Change)

(Fan On) - Change in Pressure

Push Baseline button and thenStart.

Wait several seconds while theBaseline is measured and

displayed.

Push Enter.

DG-700 shows ADJ.

Start measuring and see the truechange in pressure.


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Cruise without a computer formaintaining constant housepressure.

Cruise at 75 Pa, 50 Pa, 25 Paand 0 Pa.

Cruise 50 Pa for airsealing

and investigation.

Cruise 25 Pa for use withDuct Blaster for Duct Leakage

to Outside.

Older DG-700 Gauges maybe upgraded to add Cruise.


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Cruise control a requires a communication jackon speed controller, and a fan control cable(standard equipment).


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Older fans can be upgraded to Cruise with anew fan speed controller, a fan control cable,and a DG-700 with Cruise.

TECLOG f C b i T


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TECLOG for Combustion Tests

TECLOG is a real time datalogging program foruse with the DG-700.

Displays and records both channels.

Measure house depressurization whilesimultaneously measuring appliance draft.

A t t d T ti ith DG 700


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Automated Testing with a DG-700

Requires TECTITE softwareand USB cable (standardequipment), plus a laptop

computer.

Reduces operator errors,improves consistency betweentests.

Better precision in windy

weather.

Store test results and generate

reports.


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Blower Door Set-up Common Errors

Tubing connections to gauge are wrong.

Inputting wrong fan Flow Ring settings.

Failure to take baseline house pressure reading.

Not closing all windows and opening all interiordoors.

M l Bl D T t


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Manual Blower Door Test

Set gauge to PR/FL@50 mode.

Measure baseline house pressurewith fan covered (Baseline

feature).

Uncover fan then increase fan

speed with controller.

Adjust controller to change housepressure (Channel A) by

approximately 50 Pascals.

Read CFM50 from Channel B.

M l Bl D T t ( t )


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Manual Blower Door Test (cont.)

If Channel B shows LO whilereading CFM50, add Ring A orB, and change fan

configuration setting ongauge.

Determine if airsealing is cost

effective.

Perform airsealing work.

Retest to verify work.

Bl D T t ( t )


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Blower Door Test (cont.)

Only direct value obtained from a Blower Door testis CFM50.

All other values are calculations.

Use TECTITE software (manual or automatedmode) to help with other calculations.

Bl D T t ( t )


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The latest version of TECTITE incorporates amechanical ventilation guideline based onASHRAE Standard 62.2.

Written in Code language for adoption by localauthorities.

Bl D T t ( t )


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Estimated infiltration rates are just that -estimates, use carefully. Infiltration rates vary from day to day anddepend on parameters not measured by the

Blower Door.

Oth T t U i A Bl D


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Other Tests Using A Blower Door

Air Leakage Path investigation:

Blower Door with an Infrared Camera

View wall before Blower Door Test

View wall with Blower Door running

Oth T t U i A Bl D


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Duct Leakage Diagnostics:

Pressure Pan test to determine if duct work isconnected to the outside.

With Blower Door maintaining 50 Pa, test registerswith Pressure Pan.

Qualitative test.

Oth T t U i A Bl D


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Duct Leakage Diagnostics:

Blower Door Subtraction(compare test results withregisters sealed andunsealed).

Simultaneous pressurizationor depressurization of houseand ducts with Blower Doorand Duct Blaster (preferred

method).

Oth T t U i A Bl D


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Zone Pressure Testing:

Measure pressure change in

attached zones (e.g. attic,crawlspace) with BlowerDoor running.

Can help to quickly identifydominant house leaks.

More Useful Information


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Fan Calibration

Fans maintain their calibration unless physical

damage occurs.

These conditions are easily detected andshould be tested for on a regular basis.

Main Iss es Affecting Fan Calibration


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Main Issues Affecting Fan Calibration

The 2 most importantaspects to maintaining

proper fan calibration:

No leaks in flow sensor.

Sensor in proper

position.

Damaged fan housing

(e.g. broken flange) andbroken/ missing blades.

Checking Flow Sensor for Leaks


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Checking Flow Sensor for Leaks

Model 3 flow sensors can crack from impacts &thermal stress.

To test for leaks:

Connect a piece of tubing to the fan pressure tap.

Tape off the 4 holes on the side of the sensor.

Create a vacuum in the tubing with your mouth.

The tubing should stick to your tongue for at least 5seconds if the sensor is airtight. If sensor leaks,replace the sensor or find the source of the leak.

Remove the tape from the sensor holes.

Flow Sensor Position


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Flow Sensor Position

Because the Blower Doorand Duct Blaster flowsensors are connected to themotor, the motor determinesthe sensor position.

Motors can move if fan isdropped, or motor mountscan bend.

motor

mount

motor

Ch ki Fl S P iti


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Checking Flow Sensor Position

Measure the distancebetween the inlet plane of

the fan housing and theface of flow sensor.

Distance should bebetween 3/16 to 5/16.Adjust sensor position,

replace bent motor mountsor adjust motor position.

Digital Gauge Calibration


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Digital Gauge Calibration

Calibration is recommended once a year.

Calibration is performed at TEC factory.

Cost is $75 and is usually completed in about3 or 4 days.

Blower Door and Duct Blaster manuals

describe how to perform a calibration check inthe field.

Upgrade of older DG-700 to Cruise is an extra$50 on top of recalibration.



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Visit our website(www.energyconservatory.com)

Articles on airsealing and duct leakagediagnostics.

Previous newsletters.

All product manuals and guides are online.

Links to other sites.

Download version of TECTITE.Download of TECLOG.

Documents

179685007 Blower Door Basics PDF