ECN Forum Forums General Topics of the Trade General Discussion Area "Electric furnaces" and other odd American heaters

Those arrangements amuse me so much (as an Australian) that I had to start a thread just about them, so here I go. I guess it's just yet another American dogma (the USA being the land of the gullible) that "any" central heating (let's just forget the ancient open wood fires, which are pretty much the most obsolete technology on Earth ) is superior to portable "space" heaters in each room (to say nothing of conduction heating devices such as electric blankets and pads), so here's what I think of them:

Electric furnaces
The foremost folly of the bunch, these are basically just an oversized central fan heater.
The amusing part (to me anyway) ain't that the name itself isn't an apt description of how they work; just that having a different name falsely implies some kind of fundamental difference from portable fan heaters.

I have this on full power (2400W here, thermostat maxed-out for continuous operation) as I've typed this post, and according to my thermometer it warms the best part of my (admittedly small) house to a surprising degree (or several ). By the way, since Kambrook (unlike far too many other manufacturers) actually implement proper QA on even their budget-oriented appliances (although they've ultimately settled into more mid-priced brackets for many items), they've never had to recall a heater they've made (and little else for that matter, as you can see for yourself); take that, American brands!
That's not to say you can't buy utter junk here if you cheap out (or just choose a bad brand, so be careful what you buy if you go to Hardly Normal ), of course.

Baseboard heaters
Essentially large convectors installed in place of the skirting boards.
The only remotely interesting thing about their construction (that I've seen) is the form of heating element used, a tubular type with lots of fins fitted around it to increase the surface area (reducing the temperature presented to foreign materials inside the heater); not that this couldn't be done in a portable unit if desired, of course.
(Indeed some "panel" heaters do use sorts of finned elements, albeit made from ceramic since that's long been an "advanced" marketing buzz-word. Not that I'd pay the crazy prices often asked for them; I had one pair of pretentious 1kW units which were even confusing to operate, and they still weren't even appreciably better-built than a basic-but-competent De'Longhi HCM2030 is for about $60 Australian. )

Our portable convector heaters (the kind with generally-bare elements inside a vented box, as distinct from the finned oil-filled heaters) seem just as capable of the near-indefinite lifespan achieved by North American fixed baseboard heaters, provided the following conditions apply (beyond being competently built, obviously):

• The top grille (together with the rest of the casing) is made of metal, and not plastic with a marginal temperature rating (as some manufacturers have regretted quite badly, e.g. Goldair on their Turbo-Convectors of the 1990s).
• They are protected by just a resettable bimetallic switch (or two in series if desired for redundancy), not the common one-shot thermal fuses (Microtemp and equivalents) with their aging problem (especially if marginally set).
• They are kept reasonably clean, to prevent dust from building out of control (the moisture held by it can rust steel end terminals of the heating elements; those are usually nickel-plated, but only thinly in most cases).
• Their elements aren't distorted in such a way as to create glowing spots (when maintaining those heaters, I straighten such regions out if observed).

Why heating was centralized in the first place
In general, the main reasons for making home (or office etc.) heat central are:

• Getting rid of combustion fumes easily (which electric heaters don't produce in the first place; not at their point-of-use, anyway)
• Saving costs on control and protection hardware (of which electric resistance heaters need very little to begin with, of course)
• Some things (including PSUs by the way) work more efficiently when scaled up -- but not electric resistance heaters

So to implement central air heating using an electric resistance heater, completely misses the point (and indeed merely brings in the inevitable heat losses through the insulation, however good, of air ducting or water piping).
(The closest that any sensible arrangement gets is night-storage heaters which share a common timer; but the heaters themselves are still physically separate per-room.)

How central heating itself could be improved...
Observing just how good a well-designed fan heater is at distributing heat through the room it's in (I'd dare say Kambrook's current models are almost as good there as a Vornado would be), has made me ponder the prospects of fan-assisted heat exchangers (I won't take "radiator" as a synonym for those, since that's just so totally inaccurate) for central heat systems; basically they'd resemble water-cooling rigs for bleeding-edge computers, but maybe bigger (at least in the larger rooms). As a side benefit, the amount of heat delivered in each room could naturally be varied with the fan speed.

The flip-side of this, of course, afflicts air-conditioners used on their reverse cycle; since those (having been mounted high-up for their primary role of cooling) have to fight the natural order of air convection, hot and cold spots abound in practice (including my own home, and wherever else I've experienced them).
The same effect works against those wall-mounted fan heaters as commonly installed in UK (and to a lesser extent New Zealand) bathrooms; so I personally just use a portable fan heater in bathrooms with a 10A outlet, and a safe enough place to put the heater.

Of course, in a climate that's consistently cold (but not too cold for heat pumps to be effective) this problem could be avoided by mounting the indoor units at floor level; but Australia isn't like that.