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(no email)
Date: Wed Feb 07 2007 - 17:30:00 EST
> I think safety is the same for the ceramic or wire heater types since
> they both output 1500 watts from a small source thus both have similar
> output>
> The ceramic ones seem to offer nothing
> special but high price,
Actually they do offer special features.
First, true ceramic heaters do not have elements that heat up enough to
ignite. They use the ability to move mass amounts of air across them to
distribute lots of lower temp air then cheap units which move less air
of much higher temps.
The design of true ceramic heaters is that as the temperature of the
unit increases the ability to output heat decreases. Sounds funny, but
it means that as the elements heat up the resistors decrease the
current. This is why true ceramic heaters have strong, high revving fans
(and why some do not like them because of the noise). Lots of air blown
through them keep the elements warm instead of hot. If the air flow is
obstructed, the elements heat up more and the current drops accordingly.
The first time I saw these units was at a boat show where they had a
couple running full blast - lots of warm air coming out. But pushed
through the grate were a couple of long kitchen matches, the kind with
the big phosphorus heads with the white tips. (I used to light such by
flicking my thumbnail across the tip). Those tips were right up against
the elements, all day long, each day. They never ignited.
That is why I like true ceramic heaters, and why they cost so much vs
the cheap imitators. (I bought two that day at about $85 each and they
lasted 10 yrs). The kind I buy have circular heating elements, each
about the size of a half dollar coin, clustered together in a group of
3, 4, or five, depending on the wattage.
Stephen
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