How Does The Mat Air Curtain Work - Biddle MAT Installation, Operation And Maintenance Manual

I
NTRODUCTION
C + B
C B
Figure 1-2 MAT working principle
1) The air curtain stream is actually disturbed during the passage of a person or vehicle. However, it restores itself in seconds, as soon as the
person or vehicle has passed.
10
n
n
A
A
Note:
The MAT air curtain shown in the figures in this guide is an
example. There may be only one air curtain unit in your
MAT air curtain. Also, the size(s) of the air curtain unit(s)
may be different to suit the width of the cold store door.
However, the procedures are similar, unless specified
otherwise.

1.3.3 How does the MAT air curtain work

General
The MAT air curtain unit generates a constant, vertical air
stream, throughout the width of the doorway. It works as a
barrier between the climates of the cold store and the front
hall. By this, the exchange of heat and moisture is reduced.
Note:
Climate separation is not in effect, when the air curtain
1)
stream is disturbed. Therefore:
- All obstacles in the air curtain stream must be avoided:
even small irregularities may cause turbulence, and by
this, disturb effective working.
- All inlets and outlets must be kept free entirely.
- The doorway must be entirely open.
Principle of the MAT air curtain
MAT stands for 'Multi Airstream Technology'. According to this
principle, the stream generated by a MAT air curtain consists
of three layers, as shown in
- stream A is extracted from the front hall, and dis-
charged unheated,
- stream B is extracted from the cold store, and heated
before discharge,
- stream C is extracted from the cold store, and dis-
charged unheated.
The streams are discharged at the same speed, and combined
in a rectifier grille. By this, turbulence is avoided, and mixing of
air between the streams is strongly reduced.
C S A
OLD TORE IR
Figure 1-2:
C
URTAIN