Date: Wed, 5 Feb 2003 22:55:36 -0500
Reply-To: David Beierl <dbeierl@ATTGLOBAL.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: David Beierl <dbeierl@ATTGLOBAL.NET>
Subject: Re: pelonis ceramic heater
In-Reply-To: <F148qIfQdmEB4HGXAwx000006e5@hotmail.com>
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At 07:34 PM 2/5/2003, Mark Dorm wrote:
>I saw a pelonis ceramic heater for sale at camper world for about 80
>dollars...
They make good heaters. They made (and still make) the first widely
available ceramic-element space heater, which cost four times as much as
"ordinary" space heaters at the time, and still costs about twice what a
lot of other ceramic-element heaters cost.
>
>A quote on the box was saying this guy saved alot of money on propane
>heating his RV...
Yes, and if he didn't have to pay for the electricity he saved money
overall...but the usual way to save money with an electric heater is using
a 5,000 BTU/hr heater to heat a small space that you're actually using,
instead of running your 65,000 BTU/hr furnace that costs a lot less per BTU
but is heating a big space you aren't in.
>
>Has anyone ever used this. It was claiming to have a great thermostat,
>better at regulating temperature than a lot of other thermostats because
>theirs was external... and not constantly cycling on and off with cold/too
>hot spells..
This is a valid claim, if true. They do seem to be making an effort to
have the thermostat sensor not be influenced too much by the temperature of
the heater itself. How effective it is I don't know.
>
>The thing was honey combed...
A problem all electric space-heater makers face is explaining just exactly
why theirs is better than the others...because the basic fact is that while
electric heaters use very expensive fuel, i.e. electricity, they convert
essentially all of it to heat. Furthermore, domestic space heaters are
limited to 1500 watts consumption, which gives about 5200 BTU/hr
output. So the actual differences amount to how you get the heat to where
you want it, how well it's controlled, how obtrusive the heater is in
operation, and how safe. All the rest is smoke and mirrors, and Pelonis
has plenty of both on their website FAQ explaining why you should pay a lot
of money for a ceramic-element heater.
There are three basic types of heater, and Pelonis makes all
three: Radiant, Forced-hot-air, and Convection.
Radiant uses a hot element -- ordinarily red-hot -- and a reflector to
direct a beam of infrared radiation that directly heats surfaces that
absorb it. The air is heated very little by the infrared, but may be
heated by the warm surfaces. If you point it at yourself the sensation
(and reality) of warmth is immediate. They are mostly silent, largish,
typically a bit dangerous, and vary chiefly in how tightly the beam is
focused. A variant that was popular for a while enclosed the radiant
element in a quartz tube -- these were chiefly distinguished by a long thin
shape, usually vertical, and a considerable rattling buzz for a brief time
as the elements warmed up inside the tubes. They burn dust particles and
such and may smell slightly on that account when starting.
Convection works like a baseboard "radiator" -- it has a good deal of
surface area which gets fairly hot, and heats air mostly by
conduction. The warm air circulates naturally by convection. They are
totally or nearly silent, rather large, quite safe (for a heater), have
smooth heat control since they start and stop slowly, and only work well in
enclosed spaces where the circulating air can distribute itself without
escaping. There are tall ones that look like radiators and long ones that
look like baseboard hot-water heating.
Forced-air heaters have a fan that blows air past a hot element. They are
often quite small compared to other types. They heat up fast and throw a
rather narrow stream of hot air horizontally from their front. Some of
them swivel back and forth to distribute the air more widely. They are
noisy as a rule, and generally the smaller they are the noisier they have
to be to move the same amount of air. They're the quickest to get warm air
somewhere other than directly above them, but the narrow stream can be
annoying. They almost always have a setting that lets you use the fan
without the heater, but nobody in their right mind would put up with the
noise for the tiny amount of air they move. Within this type the heating
elements may be a hot wire or ribbon, typically somewhat short of red-hot,
or a set of ceramic elements that are intrinsically more safe because they
are cooler and have a self-regulating effect that keeps them from
overheating drastically even if the airflow is obstructed. Ceramic
elements either look like the little honeycomb disks that Pelonis are so
proud of, or like a car radiator with flat "tubes" -- the actual elements
-- with fins folded back and forth between them like ribbon candy. A
heater with "ceramic" somewhere in the name but without these distinctive
elements is probably boasting about using a ceramic device as an overheat
detector instead of a bimetal switch -- look in the fine print.
They all work, they all deliver the same amount of heat for the same amount
of power consumed. The fan-forced kind are probably most practical in a
Westy because they're small and compact. Pelonis make good ceramic ones
but I doubt they're worth as much as they charge for them -- I think it is
worth paying more for the ceramic element, just not lots more. And I'm
cranky with them because they basically lie about the advantages of their
disk-element ceramic heaters...
Beyond that you're going to have to try out or find reviews of individual
heaters to find the differences that may matter to you.
Many electric heaters get recalled, so be sure to register your purchase
with the mfr...
david
--
David Beierl - Providence RI USA -- http://pws.prserv.net/synergy/Vanagon/
'84 Westy "Dutiful Passage"
'85 GL "Poor Relation"