Retrotec DucTester 341 - Manual (Page 83)

Page 83 of 83
©Retrotec Inc. 2014
Term Definition
This ELA is sometimes called the EqLA or Canadian ELA because it was first used in the Canadian
GSB air leakage standard for houses. This ELA enjoys worldwide acceptance by most testers,
even in the US. This ELA should not be confused with another ELA that is often called the EfLA
or Effective Leakage Area. It is very unfortunate that both these ELA’s have the same acronym
of ELA. The EfLA was developed for the US ASTM Standard and is smaller than the EqLA by at
least a factor of 0.61 because it uses a discharge coefficient of 1.0. This EfLA is sometimes
called the LBL or Lawrence Berkley Labs ELA because it was developed there and is used in the
LBL natural Air Change model that enjoys wide usage apart from that usage, the EfLA is not
used very much but the existence of both can create huge problems.
When it is taken at a Reference Pressure of 75 Pa, it is often referred to as EqLA75. EqLA is
typically about twice the size of an effective leakage area that describes the same air flow rate.
See ASTM E779-10, eq. (5).
Fan Pressure The pressure difference between the inlet side of the fan and the interior of the fan. This
pressure can be read as “PrB” from Channel B on the gauge. It is used by the computer to
calculate the air flow rate through the Blower Door.
Fan Top Part on the fan where the fan’s tubing, Control Cable, and power connections are.
The Fan Top for the Model 200 refers to the two mounted red plates attached to the sides of
the fan. Attached behind them are Printed Circuit Boards (PCBs). In this manual, we will refer
to the “Control PCB assembly” as the one that has “Control” printed on the mounting plate.
We will refer to the “Power PCB assembly” as the one with the power switch on it, and has
“Mains Power” printed on it.
HVAC Heating Ventilating and Air conditioning.
Leakage A general term used to describe holes or the area of holes in in the envelope around an
enclosure.
Leakage Area This is the same as “Leakage” but expressed in sq ft or m 2 .
LEED Leadership in Energy and Environmental Design
Low-Flow Cloth Door
Panel
Cloth Door Panel used to test tight enclosures with a Model 200 fan
Manual Speed Control
Knob
The dial that is on a Fan Top to control fan speed
Open Range A Range configuration on a Retrotec Blower Door that has no Range Rings or Range Plates
attached. It is sometimes referred to as Open (22) Range since it’s diameter is 22 inches.
outdoors Outside the building in the area around the building.
Pascal (Pa) Often shown as “Pa”. A very small metric unit of pressure. There are 249 Pascals in 1 inch
Water Column (the pressure required to push water up 1 inch in a tube). One Pascal =
0.000145 psi.
Pressurization The process of creating a positive pressure in the house by blowing air into the enclosure. Air is
pushed out through all the leaks, causing the smoke to move away from the operator when
checked with an air current tester.
Range Configuration The plastic Range attachments on the Retrotec Fan. On the Model 341, Range Configurations
available are Ranges: Open, 74, 47, 29, 18, 11, 7, 3, 2 and 1.
reading A set of simultaneous Room Pressure and Fan Pressure measurements. Sometimes referred to
as a data set or test point because it is plotted as one point on a graph.
reference pressure The pressure at which the ELA is calculated, usually at the test pressure.
room See “Enclosure”.
room pressure The pressure difference created by the Blower Door between inside and outside of the
enclosure. This pressure is commonly measured by Channel A on the gauge.