Retrotec DM32 User Manual download pdf (Page 92)

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©Retrotec Inc. 2014

Glossary

Term

Definition

Air Current Tester

Neutrally buoyant smoke (manufactured by Retrotec Inc.) used to locate leakage locations, and

to observe the direction of air flow, or to see if pressure neutralization between two zones is

reached.

air leakage

Pertains to how leaky an enclosure may be; The movement/flow of air through the building

Envelope, which is driven by either or both positive (infiltration) or negative (exfiltration)

pressure differences or test pressures across the building Envelope.

background pressure

See “Baseline pressure”

Baseline pressure

Pressure that exists when the enclosure has been prepared for the test, but before the fan is

activated. There is always some Baseline pressure due to stack, wind, flues and active HVAC

systems. There are two components of Baseline pressure. A fixed Baseline offset (usually due

to stack or HVAC) and a fluctuating pressure (usually due to wind or elevator operation). A

method determining baseline pressure is by having a digital gauge accumulate readings over an

adjustable time period

(Note: The terms “static pressure”, “bias pressure,” and “zero Fan Pressure difference” are used

interchangeably with the term baseline pressure in other documents/standards used in the

industry.)

CFM

Cubic feet per minute, the units of volumetric flow

Control Cable

An Control Cable used to control Retrotec fans

Control port

Control port on a Retrotec fan, labeled “Control”

Depressurization

The process of creating a negative pressure in the enclosure by blowing air out of it. Air is

drawn in from outside to replace it, showing up as “geysers” when checked with an air current

tester.

digital gauge

A gauge with an electronic pressure sensor and digital display that is capable of reading in

tenths of a Pascal.

Door Fan

A test instrument that fits into an open doorway in order to pressurize or depressurize an

enclosure. It is a calibrated fan capable of measuring air-flow, and is used while mounting it

into a doorway.

A Door Fan is often called a “Blower Door” or an “Infiltrometer™”.

Door Panel

A solid or flexible panel used to temporarily seal off a door way while allowing for the

installation of a fan for the purpose of blowing air into the building in order to measure the air

leakage rate or to provide a pressure to assist in the location of air leaks.

DucTester

Retrotec’s duct testing system is named the DucTester.

effective leakage area

A common term used to describe air flow at a pressure by equating it to an equivalent size hole

in an elliptical nozzle that would pass the same air flow at the same test pressure. It is usually

taken at 4 Pa and incorporates a 1.0 discharge coefficient. It is typically about half the size of an

equivalent leakage area that describes the same air flow rate. See ASTM E779-10, eq. (5).

enclosure

The surface bounding a volume, which is connected to outdoors directly. For example an

apartment whose only access to outdoors was through a doorway that leads directly outdoors.

Or, a building with a series of apartments or offices whose only access to the outdoors is

through a common hallway then the enclosure would be the volume that bounds all of the

apartments or offices.

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