FloAire BI-FARM User Manual

Use of Utility Sets Indoors

(Suggestions based on UL and NFPA documents )

Some situations prevent the installation of exhaust fans on the
roof or other outdoor location. An indoor installation may be the
only alternative.

Of the various types of fans that might be employed, the
BI-RM Series seems most appropriate because it readily
accommodates the connection of inlet and outlet ducts.
Fans designed for curb mounting would present inlet duct
connection difficulties.

But is it safe, and how should it be installed? The logical organi­zations to check for information are UL and NFPA. Their stan­dards are usually the basis for local codes.

Standard UL762 (officially called a “Subject”) “Power Roof
Ventilators for Restaurant Exhaust Appliances

This standard has two primary tests. The first test has the fan
exhaust air for several hours at the maximum temperature the manufacturer wishes to list the fan,
such a 300 F. The second part imitates a grease fire by igniting grease in a pan near an inlet duct. If
the fan keeps running and does not display any unsafe results it passes those tests. They also exam­ine the fan for any characteristics that might be unsuitable.

In the scope, section 1.1, it says “these requirements cover roof or wall-mounted ventilators for res­taurant exhaust appliances.” It would seem at first that the phrase “roof or wall mounted” would pre­clude applicability of the label indoors. However, in the very next paragraph it goes on to say “Power
ventilators...covered by these requirements are intended for installation in accordance with ...NFPA

96.” NFPA 96 clearly defines how to install a traditional “roof mounted ventilator” indoors.
So, on to NFPA
NFPA 96 (Standard for Ventilation Control and Fire Protection of Commercial Cooking Operations.)

Happily, beginning with NFPA 96, there is specific ref­erence to fans installed within the building in section

8.1.3.2. .
Our interpretation:

1. The fan inlet and outlet must be connected to the
ducts using companion flanges and high temperature
(1500F) gasketing.

This is the only troublesome requirement. The contractor
will need to provide and install the companion flanges
and gasketing. For the round inlet they need companion

flange, rolled angle rings,
various sources like http://www.cmrp.com
tangular outlet common angle iron welded into a frame

will suffice.
The high temperature gasketing can probably be obtained from the manufacturers of grease duct ac­cess doors, like DuctMate, or an industrial supply house.

which are available from

. For the rec-

2. Install the fan where there is room for service and removal.

3. Usually the duct to the fan is in a shaft and the shaft walls have a fire resistance rating. The
space where the fan is located must have the same fire resistance rating as the shaft.

4. Flexible connectors are not allowed.

5. There must be a drain in the fan (there is) and it is to be connected to an easy-to-service
grease receptacle of no more than 1 gal capacity.

6. Fan housings shall be 16 gauge steel minimum. Housings are 16 gauge steel mini-

mum, heavier on large sizes.

7. The ducts into and out of the fan must have access doors within 3 feet of the fan.

8. Minimum clearances are, 18 inches to combustible, 3 inches to limited combustible, and 0
inches to non-combustible materials.

9. All wiring and electrical equipment must comply with NFPA 70, National Electrical code.
End