I.C.E. BMA-136 HBR User Manual
Minimum clearance from the unit, to combustible construction, is clearly marked on the rating plate attached to the unit.
No source of flammable vapors, gases or dust shall be with in 20’ horizontally of any unit unless that source is separated from
the unit by an enclosure of fire and vapor resistive materials.
On indoor suspended units, when necessary to provide working clearance beneath the unit, the installation shall be made at a
suitable height above the floor.
1. On indoor units, install fresh air duct to inlet of unit. Install intake hood or louvers with screen.
a) Make required opening in wall and line with angle frame inside. Should be completed before outside is
started to avoid crumbling.
b) Insert insulated fresh air “collar” through opening with flanges turned out to provide rigidity.
c) Anchor intake hood with birdscreen to wall.
d) Caulk perimeter of opening to make rain tight.
2. Connect discharge air duct or discharge grille to unit outlet. If unit is installed on a roof, be sure that the duct going
through the roof is adequately flashed and sealed to prevent leakage. (see figure 1).
3. Where a ductwork system or other enclosure is directly connected to the inlet or outlet of the heater is such a way as to
cause a possible gas trap and accumulation of a flammable mixture, a pre-purge cycle shall be incorporated to provide not
less than 4 complete air changes of the duct work or enclosure by volume prior to an ignition
4. Where additional automatically operated inlet or discharge air louvers are used, they shall be electric interlocked to ensure
the maximum designed opening before either starting or running circuits may be energized.
Fire dampers installed in inlet or outlet duct systems shall be interlocked to shut down the unit in case of fire in the duct work
and should be arranged so that the unit will only be electrically energized when in the wide open position.
In the event that the make-up air heater failure creates a hazard to other fuel burning equipment in the building the unit shall be
interlocked to open balancing inlet air dampers. These dampers can be of the motorized type, (see wiring diagram).