Theory of Operation. Desa Tech SBLP375AT, 375-F, BLP375AT

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.

Combustion Chamber Ignitor

Fan

Motor

Clean

Heated

Air Out

(Front)

Cool

Air In

(Back)

DSI

Power Cord

Air For Combustion

Air For Heating

Nozzle Solenoid Valve

Air For Combustion Air For Heating

Figure 2 - Cross Section Operational View

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 local 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 at tank location

Number of tanks

40° F (5° C) and above 2

Below 40° F (5° C) (Use larger tank)

Hose/

Regulator

Assembly

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 surrounding air temperature rating for each heater is -20°F (-7° C).

VENTILATION

WARNING: Follow the minimum fresh, outside air ventilation requirements. If proper fresh, outside air ventilation is not provided, carbon monoxide poisoning can occur. Provide proper fresh, outside air ventilation 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.

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