I would like to make an electric heater. It will have a 20" Lasko Box fan at the back, pushing air passed the Kanthal A1 resistance wire.

I would like to use 120vac. It will dissipate 1000 watts, and draw 8.33 Amps, using a resistance of 14.4 Ω's

I will use Kanthal A1 resistance wire for the fact that Kanthal A1 resistance wire has a higher tempature threshold that NiChrome 60 resistance wire.

I'm aware of the length needed to hit a specific target resistance, to hit a specific target power output.

I would like to use a wood frame, and stainless steel eye bolts for the connections.

If I can't use wood, then what could I use for the box frame for the unit? Most space heaters use plastic casing, so I don't see why using a wood frame would be any different.

Is this possible?

  • \$\begingroup\$ There's a bit too much rambling in your question. Wood is not a good choice of material for an electric heater. It is highly flammable. Don't get hung up on exact voltages. Your mains will vary by up to 10%. \$\endgroup\$ – Transistor Jan 20 '16 at 8:09
  • \$\begingroup\$ I corrected the rambling. Could you explain what else I could use, besides steel for the box, or case? I'm well aware that the mains voltage will not be exactly 120vac, that's acceptable. \$\endgroup\$ – Roy A. Jan 20 '16 at 8:44
  • \$\begingroup\$ Here's just a small picture I drew up in InkScape as a small illustration for what it the front will look like. In the back there will be a box fan pushing air thru the wire oi66.tinypic.com/28svl1d.jpg \$\endgroup\$ – Roy A. Jan 20 '16 at 9:10
  • \$\begingroup\$ 1 kW electric space heaters are very cheap. Just buy one. \$\endgroup\$ – Dave Tweed Jan 20 '16 at 14:25

You should buy a cheap heater instead of doing this possibly very dangerous machine, but:

You could probably use a UL94 V0 plastic of some sorts for the enclosure. But I would place the metal wire construction on a separate metal frame inside the plastic housing, with some distance between them. Of course with a metal frame for the wires, you need to think of a way of routing them so they don't short circuit.

And also make totally sure that no metal parts can be touched from the outside. You should also add overheating and short circuit protection of some sorts. A PTC fuse for the overheating and a "normal" ceramic/glass fuse for the short circuit. All cables inside the housing that leads to the Kanthal wires must have insulation that can withstand high temperature.

UL 94 classification:

V-0: burning stops within 10 seconds on a vertical specimen; drips of particles allowed as long as they are not inflamed.


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