Desa 375-F - Manual (Page 4)

www.desatech.com 116699-01B 4
THEORY OF OPERATION
The Fuel System: The hose/regulator assembly attaches to the propane gas supply. The propane gas
moves through the solenoid valve and out the nozzle.
The Air System:
The motor turns the fan. The fan pushes air into and around the combustion chamber.
This air is heated and provides a stream of clean, hot air.
The Ignition System: The direct spark ignitor (DSI) sends voltage to the ignitor. The ignitor ignites
the fuel and air mixture.
The Safety Control System: This system causes the heater to shut down if the flame goes out. The
motor will continue to run, but no heat is produced.
PROPANE SUPPLY
Propane/LP gas and propane/LP tank(s) are to be
furnished by the user.
Use this heater only with a propane/LP vapor
withdrawal supply system. See Chapter 5 of the
Standard for Storage and Handling of Liquefied
Petroleum Gas, ANSI/NFPA 58 and the Propane
Installation Code CAN/CGA B149.2. Your lo-
cal library or fire department will have these
booklets.
The amount of propane/LP gas ready for use from
propane/LP tanks varies. Two factors decide this
amount:
1. The amount of propane/LP gas in the tank(s)
2. The temperature of tank(s)
The chart below shows the number of 100-pound
tanks needed to run this heater.
Do not operate this product with any tank smaller
than 100 pounds.
Temperature Number
at tank location of tanks
40° F (5° C) and above 2
Below 40° F (5° C) (Use larger tank)
Less gas is vaporized at lower temperatures. You
may need a larger tank in colder weather. Your
local propane/LP gas dealer will help you select
the proper supply system. The minimum sur-
rounding air temperature rating for each heater
is -20°F (-7° C).
VENTILATION
WARNING: Follow the mini-
mum fresh, outside air ventila-
tion requirements. If proper
fresh, outside air ventilation is
not provided, carbon monoxide
poisoning can occur. Provide
proper fresh, outside air ventila-
tion before running heater.
Provide a fresh air opening of at least three square
feet for each 100,000 Btu/Hr (105,500 k/j) rating.
This heater requires a fresh air opening of at least
11.25 square feet (1.05 m 2 ). Provide extra fresh air
if more heaters are being used.
Air For Combustion Air For Heating
Cool
Air In
(Back)
Motor
Nozzle
Power Cord
Hose/
Regulator
Assembly
Solenoid Valve
Ignitor Combustion Chamber
DSI
Figure 2 - Cross Section Operational View
Fan
Clean
Heated
Air Out
(Front)
Air For Combustion
Air For Heating