– 34 –
SECTION XI - RECIRCULATION
WARNING: On Heaters, which recirculate room
air, outside ventilation air must be provided in
accordance with the information shown on the
heater nameplate.
Recirculation of room air may be hazardous in the
presence of:
• flammable solids, liquids and gases
• explosive materials such as grain dust, coal dust,
gunpowder, etc.
• substances such as refrigerants or aerosols which
may become toxic when exposed to heat or flame
Recirculation is not recommended in uninsulated
buildings where outside temperatures fall below 32°F
(0°C).
Excessive recirculation or insufficient ventilation air,
which results in inadequate dilution of combustion
products generated by the heater, may create hazard-
ous concentration of carbon monoxide, nitrogen
dioxide, and other combustion products in the heated
space.
If gas fork trucks or other fossil fuel powered equip-
ment are utilized in the conditioned area, additional
ventilation requirements for the facility must be ad-
dressed separately.
The heater inlet shall be located in accordance with
applicable building code provisions for ventilation air.
Field constructed intake accessories should be
properly designed to minimize the entry of snow and
rain.
All ventilation air to the heater shall be ducted directly
from the outdoors.
If in doubt regarding the application, consult the heater
manufacturer.
ETL labeled heaters must be equipped with a control
system and an air measuring station provided by the
heater manufacturer and installed on the return air
damper or duct.
To Next Page
Loading...