Heaters

[NES304]

I don't know much about heaters and demisters and would like a little direction with them. It looks like there are two types, a 12v fan type and one with a core that runs water from the radiator.

Are these independant or needed to run together?
Cheers

[EffCee]

The most common type of heater run a heater core which is like a small radiator. The hot water passes through the heater core, and the fan blows or sucks air through heater core. By having a system of doors or flaps this enables you to control where the heat travels to.

For example on either the Bosch or the Nasco Warmaride you could close the doors on the front of the heater which stopped heat going into the car and this would direct warm air to the vents at the windscreen (if fitted). Most time you could strike a happy balance and have the doors or flaps partially open and demist the windsceen as well. That way you stayed warm and there was no fog on the window. There is also a japanese unit which is nearly identical to the above mentioned units, or there is the Smiths Beehive heater as well.

Other types, which are a lot less common, relied on the heat from the radiator and directed warm air from the radiator into the car. Same principle, but more untidy in the engine bay. There was also heat lost as the air travelled from the radiator into the car. Another disadvantage was that you also got the dust or exhaust fumes from the car in front.

HTH

Keith