Theory Of Operation - Desa B115T Owner's Manual

115,000 Btu/Hr H.S.I. Series
PORTABLE FORCED AIR HEATER
FUELS
WARNING: Use only kerosene
or No. 1 fuel oil to avoid risk of fire
or explosion. Never use gasoline,
naphtha, paint thinners, alcohol,
or other highly flammable fuels.
Do not use heavy fuels such as No. 2 fuel oil
or No. 2 Diesel. Using heavy fuels will result
in a clogged fuel filter and/or nozzle.
IMPORTANT: Use a KEROSENE ONLY
storage container. Be sure storage container is
clean. Foreign matter such as rust, dirt, or
water will cause the ignition control assembly
to shut down the heater. Foreign matter may
also require you to clean fuel system often.
VENTILATION
Follow the minimum fresh,
outside air ventilation require-
ments. If proper fresh, outside air
ventilation is not provided, car-
bon monoxide poisoning can oc-
cur. Provide proper fresh, out-
side air ventilation before run-
ning heater.
Provide at least a three-square-foot opening
of fresh, outside air for each 100,000 Btu/Hr
rating. Provide extra fresh air if more heaters
are being used.
Example: A 115,000 Btu/Hr heater re-
quires one of the following:
• a two-car garage door (16 feet wide open-
ing) raised three inches
• a single-car garage door (9 feet wide
opening) raised five inches
• two 30 inch wide windows raised eight
inches
THEORY OF
OPERATION
The Fuel System: The air pump forces
air through the air line. The air is then
pushed through the nozzle. This air causes
fuel to lift from the tank. A fine mist of fuel
is sprayed into the combustion chamber.
The Air System: The motor turns the fan.
The fan pushes air into and around the
Combustion Chamber
Clean
Heated
Air Out
Fuel
Nozzle
Tank
Air For Fuel System
Figure 3 - Cross Section Operational View
4
combustion chamber. This air is heated and
provides a stream of clean, hot air.
The Ignition System: The ignition con-
trol assembly provides power to the ignitor.
This ignites the fuel/air mixture in the com-
bustion chamber.
The Flame-Out Control System: This
system causes the heater to shut down if the
flame goes out.
Motor
Ignitor
Fan
Fuel
Air Line
Filter
To Burner
Air For Combustion
And Heating
Air Pump
Air Intake
Filter
Cool
Air
In
Air
Output
Filter
Ignition Control
Assembly
Fuel
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