[HN Gopher] How to Assemble an Electric Heating Element from Scr...
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How to Assemble an Electric Heating Element from Scratch
Author : surprisetalk
Score : 78 points
Date : 2025-10-19 13:25 UTC (9 hours ago)
(HTM) web link (solar.lowtechmagazine.com)
(TXT) w3m dump (solar.lowtechmagazine.com)
| cenamus wrote:
| Some solution with a maximum power point tracking inverter would
| probably be a whole lot more efficient. But probably depends a
| lot on the exact resistances and panels involved.
|
| But I guess that would go against the "low tech" spirit. And if
| panels aren't the limiting factor why not
| amelius wrote:
| No short-circuit protection?
|
| [Also, I don't like the quality of the images. How can I take
| their advice seriously if the images are barely viewable. It
| looks like someone actually made an effort to reduce the quality
| of the images. For artistic effect, probably. Don't do that.]
| LooerCell wrote:
| About the quality of the images, it's on purpose:
|
| > By dithering, we can make images ten times less resource-
| intensive, even though they are displayed much larger than on
| the old website.
|
| This is needed because the website is solar-powered and self-
| hosted on low-tech hardware, read more here:
|
| https://solar.lowtechmagazine.com/about/the-solar-website/
| gblargg wrote:
| I just took the original first image from the article and
| compressed it to a 37k JPEG, the same size as the dithered
| image, and it looks a lot better. They must be considering
| resources to display the image, not just file size and
| network bandwidth.
| chuho wrote:
| Images aren't like that for artistic effect, but for lower
| energy consumption.
|
| > We further apply default typefaces, dithered images, off-line
| reading options, and other tricks to lower energy use far below
| that of the average website.
|
| https://solar.lowtechmagazine.com/about/the-solar-website/
| amelius wrote:
| Ok, I didn't read that. But I still think it's _not_ a good
| idea to do that for a topic where personal safety is at
| stake. And besides, the quality is really too low anyway. I
| can barely recognize the thermocouples in those images.
| aposm wrote:
| How can I take your comment seriously if you didn't read
| the article? It looks like someone didn't actually make an
| effort to understand the context of the images.
| creer wrote:
| At the bottom of the page:
|
| Battery status 63%, not charging Power used 2.69W Uptime 5
| weeks, 11 hours, 36 minutes
|
| Traffic from HN may be a problem today...
| teeray wrote:
| > It looks like someome actually made an effort to reduce the
| quality of the images. For artistic effect, probably.
|
| They did, and it's part of the footprint-reduction techniques
| used to host the site off solar full-time.
| https://github.com/lowtechmag/solar/wiki/Solar-Web-Design#im...
| amelius wrote:
| I don't know, they are making electric heaters.
|
| Might as well use your server to generate some of that heat
| ...
| mysteria wrote:
| That's fine for the main article but I think there should be
| a way to get higher quality images should the reader request
| them. If power is a concern those can be hosted elsewhere.
|
| I think it's acceptable for the drawings to be compressed
| this way but the photographs are very unclear.
| AmosLightnin wrote:
| There is. Click the small pixely looking X at the end of
| the photo's caption.
| mysteria wrote:
| I see. They should make it more obvious.
| quickthrowman wrote:
| > No short-circuit protection?
|
| That's the first thing I noticed too. You can buy a
| 277VAC/60VDC 7A DIN rail miniature circuit breaker that can
| handle 7,500 amps of fault current for $20 [0] there's no
| excuse other than ignorance for the lack of overcurrent
| protection. I only know how to use a calculator to figure out
| AC fault current but that should be enough to handle a solar
| panel.
|
| It does mention an optional thermal switch and optional thermal
| fuse, my sauna stove definitely has a thermal switch and I'd
| include one if I was building this thing too.
|
| [0] https://www.digikey.com/en/products/detail/phoenix-
| contact/1...
| amelius wrote:
| So glad someone responded to the main part of my comment.
| quickthrowman wrote:
| I'm an electrical PM so the lack of overcurrent protection
| jumped out at me, I have to consider overcurrent protection
| for every single circuit I reason about, it's mandatory and
| should be included in this installation.
|
| The image part of your comment was nerd bait so everyone
| replied to that :P
| throwaway173738 wrote:
| Why not use cast or wrought iron and fire bricks for a higher
| temperature rating? What you'd have then is basically a wood
| stove except with the wood replaced with electricity.
| 1970-01-01 wrote:
| ElectroBOOM had the idea first and did it better.
|
| https://www.youtube.com/watch?v=MrnCDKB1hE0
| killingtime74 wrote:
| Next article, how to mine your own nickel from scratch? "It's a
| lot cheaper"
| realty_geek wrote:
| True story (even though as the years go by I find it hard to
| comprehend myself)
|
| I was in a boarding school in Ghana in the late 80's and pretty
| much every day there would be someone boiling water with a fork
| directly wired to a 240 volt socket. All the beds were metal bunk
| beds and there was plenty of combustible material in each
| dormitory.
|
| I am pretty sure this was replicated in the dozens of other
| boarding schools across the country. Somehow I never heard of any
| deaths or serious injuries from it.
|
| Not in the slightest bit advocating for it. It was a desperate
| solution in desperate times but it has massively skewed my
| comprehension of risk compared to pretty much anyone I meet in
| Europe.
| mixmastamyk wrote:
| Not uncommon in Brazil to have an electric water heater
| installed on a shower head, sometimes with lightly covered
| wiring. Was gobsmacked when I first saw them. One even gave me
| a tingle when touching the faucet and I told the owner. :sweat-
| smile:
| twodave wrote:
| I remember some showers I took in Rio that, to my
| surprise/dismay, required bringing a match along to light the
| water heater within the shower. That now seems tame by
| comparison.
| estimator7292 wrote:
| My flat in Czechia had a gas burning tankless water heater
| _in_ the shower. Standard tub with a shower head and water
| heater directly on the wall.
|
| The floor of the tub was also at least 10" above the
| bathroom floor. I literally broke a rib trying to get out
| of the damn thing
| hagbard_c wrote:
| Those things were everywhere in the Netherlands when I
| was a child - 70's. I had one above the sink in the
| kitchen in my student apartment (half of a pigsty
| converted to human habitation, pigs in the other half, a
| thin wall in between - that's what you get when studying
| at an agricultural university and living on a farm)
| running off a propane tank in the garden. We had one in
| the kitchen and a bigger one in the bathroom, running off
| natural gas which the country had plenty of after the
| discovery of a large gas deposit in the northern
| Netherlands. There were no vents to the outside, the
| things just vented into the room. They're called
| 'geisers' (geysers) in Dutch.
| gambiting wrote:
| Extremely common in the UK too - you just have a 7.2kW feed
| going into your shower cabin, while regulations prohibit you
| from having any electrical sockets anywhere in the bathroom
| lol.
|
| Which leads to an idiotic situation where in Europe it's
| extremely common to have your washing machine in the
| bathroom, but in the UK everyone goes "oh no we can't have
| that it's extremely unsafe" while standing next to an
| electric shower fused at 32amps.
|
| Tbf the building regulations are meant to make it somewhat
| safe, but I've personally seen dodgy work done by
| electricians where they wired a shower using a 16amp wire
| which obviously subsequently melted after some use.
| asdefghyk wrote:
| Sounds like a instantaneous electric hot water heater.
| Quite common, in places like Philippines, that do not have
| cool/cold air temperatures, and less developed electricity
| supply.
| quickthrowman wrote:
| The UK doesn't allow any receptacle circuits in a bathroom?
| Not even if they're protected with an RCD? That's a GFCI
| for Americans.
|
| I am well acquainted with throwing water on resistive
| heating elements from taking a lot of electric saunas, so
| electric instant hot water heaters don't really scare me.
| The proximity of the current is irrelevant to me when just
| 30 mA will kill you.
|
| Electric tank water heaters work on the same principle, a
| high resistance conductor encased in a ceramic insulator
| which is encased in metal.
| gambiting wrote:
| >>The UK doesn't allow any receptacle circuits in a
| bathroom? Not even if they're protected with an RCD?
| That's a GFCI for Americans.
|
| So to be fair - until last year(or 2023?) you couldn't
| have them at all, then they changed the rules to say you
| can, but they have to be at least 3 metres away from the
| nearest bath or shower. For reference, my entire bathroom
| is 2.5m by 2m - and I suspect 99% of British bathrooms
| aren't much bigger than this. So in theory - you can. In
| practice....not so much.
| jasonwatkinspdx wrote:
| Yeah, got one of those in a hotel in Florence. Definitely
| weirded me out conceptually, but I assume they're not
| electrocuting people on the daily so whatever.
| dlcarrier wrote:
| As so someone living in the US, I'm often amazed by most the
| rest of the world relying on outlets and plugs for safety,
| instead of safer voltages.
| Joker_vD wrote:
| Heh. Or shaving blades [0]. Just don't touch the water!
|
| [0] https://www.youtube.com/watch?v=MjJ1N4uJyV8
| RRWagner wrote:
| I only half-humorously thought the article would include how to
| make the wire from ore, or at least a functional equivalent.
| pengaru wrote:
| So many complaints about dithered images when they're effectively
| thumbnail equivalents, click on the pixelated X for the original,
| ffs people.
| aurizon wrote:
| Nichrome increases in resistance with temperature = choose the
| right wire gage and coil length and you can achieve a steady
| state at a particular voltage which will mean it will approach a
| temperature = not burn food, although this design does not look
| like it will have that problem - unless the insulation allows it?
| goda90 wrote:
| This pairs well with their other articles on heating like one
| about using hot water bottles to heat people instead of rooms.
| https://solar.lowtechmagazine.com/2022/01/the-revenge-of-the...
| avipars wrote:
| Reminds me of The Toaster Project
| Doohickey-d wrote:
| One thing to be aware of: nichrome wire heats up. Solder melts
| with heat. So if you solder them together, and your nichrome wire
| gets hot enough, they will not stay attached. Hence commercial
| devices use a mechanical, crimp connection.
|
| Probably not an issue for oven or cooking temperatures, but it is
| if you're working on hotter things like heaters or hairdryers and
| such.
| CamperBob2 wrote:
| Good luck soldering nichrome in the first place, though, at
| least without using some kind of crazy acid-core solder. You'll
| need to crimp it.
| Arrath wrote:
| The article seems to recommend wrapping several coils of
| nichrome around the wire supplying electricity, and just
| globbing a load of tin solder on. Not ideal, I'd say.
| Aurornis wrote:
| Your standard electronics solder is not going to stick to
| nichrome anyway. You have to seek out special brazing materials
| and difficult fluxes to even get that far.
|
| This article tries to use large solder blobs to mechanically
| trap the nichrome wire, which I don't recommend for the reasons
| above. You really should use a crimp connection.
| analog31 wrote:
| The appliances I've opened up used spot welding.
| dlcarrier wrote:
| Crimps are also far more vibration resistant than solder
| joints, which is especially necessary with wire-to-board
| connections.
| awesome_dude wrote:
| Just a nit pick... but
|
| Don't all metals melt with heat...?
|
| What I think you mean to say is that (some) solders melt at the
| temperatures that this heating device operates at?
| asdefghyk wrote:
| The description in the comment Im replying to - reminded me of
| the replaceable element in electric jugs, which where common
| during 1970s. The nichrome wire was meant to be replaceable ,
| so had a mechanical connection , not soldered.
| Here is a good picture of what I have attempted to describe
| .... https://www.lighting-
| gallery.net/gallery/displayimage.php?pos=-130368
| exitnode wrote:
| Here's a similar approach for converting a trackball or mouse
| into a heated input device: https://rz01.org/heated-trackball/
| userbinator wrote:
| _Heat-resistant electric cable. These electric wires are
| encapuslated in silicone mesh rather than plastic._
|
| Silicone is not commonly used for this purpose. More common these
| days is fiberglass, and long ago it was asbestos.
| moron4hire wrote:
| It's a filter checkbox on McMaster-Carr when searching for High
| Temperature Cable. It also is the largest sub group in that
| category.
| louwrentius wrote:
| Lowtechmagazine is building a solar powered electric oven [0].
| This is why they want to build an electric heating element that
| works on a relatively low voltage.
|
| [0]: https://solar.lowtechmagazine.com/2025/10/how-to-build-a-
| sol...
| asdefghyk wrote:
| I've always been curious how modern electric heating elements are
| assembled in a safe manner. I mean ones that use nichrome heating
| wire , inside a metal tube. The metal tube is packed with
| insulating material. Like how is the heating wire maintained in a
| position so it touches the smallish diameter metal pipe.
|
| From Google - about how manufactured ....An electric heating
| element inside a metal pipe is a common design for tubular
| heaters, which consists of a resistance wire (often Nichrome)
| coiled in the center of a metal tube. The space between the wire
| and the tube is packed with an electrical insulator, such as
| magnesium oxide powder, which conducts heat efficiently while
| preventing the wire from shorting against the pipe. This design
| allows for durable, efficient heating as the heat is conducted
| from the element to the pipe's outer surface....
| Arubis wrote:
| Anything's an electric heating element if you can jam enough
| current through it.
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(page generated 2025-10-19 23:00 UTC)