FloAire Indirect Fired Heater User Manual
Page 5
5
Recommended Supply Ductwork Sizes
Blower Size
Straight Duct Length
10
48 in.
15
72 in.
18
86 in.
drastically increase the static pressure and
reduce airflow. The chart below shows the
minimum fan outlet duct sizes and straight
lengths
recommended
for
optimal
fan
performance. Follow SMACNA guides and
recommendations for the remaining duct
run. Fans designed for rooftop installation
should be installed on a prefabricated or factory built roof curb. Follow curb manufacturer’s instructions
for proper curb installation. The unit should be installed on a curb and/or rail elevated not less than 20”
above any surface. Be sure duct connection and fan outlet are properly aligned and sealed. Secure fan
to curb through vertical portion of the ventilator base assembly flange using a minimum of eight (8) lug
screws, anchor bolts, or other suitable fasteners (not furnished). Shims may be required depending upon
curb installation and roofing material. Check all fasteners for tightness. The diagrams below show
different mechanical installation configurations.
Roof Mount Installation
Installation with Exhaust Fan