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How Does A Cabinet Heater Work?

A cabinet heater is usually controlled by a thermostat and time clock mounted in a small enclosure. If the time clock switches on and the temperature is cold, the cabinet heater will be switched on. If a frost thermostat is included the cabinet heater will switch on independent of the time clock as long as the temperature is cold enough.

A pre packaged burner attached to the front of the warm air heater will turn on. A control box on the burner will start the burner fan and try to ignite the fuel. If the fuel ignites the control box will detect this and the fuel supply will remain on. If the burner does not ignite the control box will shut the burner down and lock out for safety reasons. Generally a red neon will illuminate on the control box. A manual reset is required to operate the burner again.

The fuel burns inside a drum shaped chamber inside the cabinet heater. As the fuel burns, products of combustion are forced around a series of heat exchanger tubes before leaving the heater through the flue at the top or rear of the warm air heater.

The heat exchanger warms up quickly and the air around the heat exchanger inside the cabinet heats up activating a thermostat (fan and limit) usually located at the top of the heater.

This thermostat activates the fan in the bottom of the heater which sucks cold air from the room into the bottom of the heater. As the cold air is blown over the heat exchanger it heats up where it leaves the top of the heater through nozzles and can be pointed to direct the hot air where needed.

If the cabinet heater should overheat an additional thermostat (high limit) will switch the burner off and allow the heater to cool down. A manual reset is required to operate the heater again.

Usually a switch can be operated in the summer to turn the fan on without the burner, to help ventilate a room.

Powrmatic heaters are very common in large warehouses and factories and are recommended by Magma Energy Services Ltd.

Philip Hamer

Magma Energy Services Ltd

Saturday, March 28th, 2009.