This option includes exhaust hoods
and gravity dampers located in the
return air section (Figure 22). When
the pressure of the building
increase, the gravity dampers open
and relieve air to the outside.
If the return air duct pressure drop
is higher than the building
overpressure, the gravity dampers
will not open.
If the return air duct pressure drop
is lower than the building
overpressure, the gravity dampers
will open and releive air outside of
the building.
Unit Options
43
RT-SVX19A-E4
Barometric relief
The barometric relief allows to
minimize overpressure in the
building caused by the introduction
of fresh air. This option is typically
installed when fresh air intake is
below 25% of the nominal air flow
and when the return air pressure
drop is below 25Pa.
Figure 21 - Economizer flow chart with barometric relief
Downflow version
Horizontal flow version
R = return
S = supply
F = fresh air
E = exhaust
S
R
F
E
S
F
R
