Spring Air Systems Truflow-TC Installation and Operating May 2021
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Truflow-TC automatically changes the exhaust and supply to suit the actual cooking operation at any given
time during the cooking day.
Automatic Design
The TRUFLOW-TC is an automatic design that will modulate the fan speed based on the rise and fall of
the duct-collar air temperature. If at any time during the cooking operation, the exhaust volume of air does
not keep up to smoke generated simply touch the MAX AIR button on the DASHBOARD screen. This
situation could occur when:
Large quantities of greasy foods are tossed on the grill at one time or
A large tilting skillet or kettle is opened quickly or
A combination oven door is opened without releasing steam slowly at door or
A draft from a door or window opening.
Minimum duct velocity in the Building Code
The National Fire Protection Association, NFPA-96 2001, code changed to provide for a
reduction of the exhaust air from a commercial kitchen during low demand periods. The
minimum duct velocity in the NFPA-96 2001 has been reduced from 1500 fpm to 500 fpm. In
addition, the International Mechanical Code, IMC, was changed in 2003 to allow for the
reduction in exhaust from a commercial kitchen during low demand periods. The building and
fire departments have these codes in their possession and will have no reason not to allow a
Truflow-TC installation anywhere in North America.
Sizing the Exhaust Ductwork
We recommend that the engineer size the exhaust ductwork for 1670 fpm velocity. The NPFA-96 code
allows for a reduction in duct velocity to 500 fpm. By sizing the ductwork at 1670 for 100% exhaust and
duct velocity will be 500 fpm at 30% exhaust volume.
How many hoods can be connected to each exhaust fan?
The Truflow-TC is available for connecting up to two exhaust fans with two supply fans and, a total of 12
exhaust hoods. You could have two fans with six hoods each or one fan with twelve hoods. Maximum
energy savings will be achieved with two fans and six hoods each arrangement, because the fans would
operate as independent kitchens.
NFPA-96, 2001
8.2 Airflow
8.2.1 Air Velocity
International Mechanical
Code. 2003
Section 507 Commercial
Kitchen Hoods
507.1 General
