110V ceramic heater elements

[mora]

Hello,

I'm in progress of converting a car to electric. I need heater because of climate here (worst case around -30C, or -22F according to google, hehe). I'm using 96V system. Here in europe we have 220V devices. 1000-2000W heaters are cheap enough but those are rated at 220V. If I tear one apart and apply 96V DC into it, it won't produce much heat I guess.

I thought about 110V elements, but can't find any cheaply from eBay. I actually need only elements, not the full plastic case heater. I see lots of US webstores have them available, but none of them does international shipping.

I suppose 110V elements would do the trick if 96V DC is applied to them. Right? At least much better than to apply 96V DC to 220V element. I also believe I need two of them connected to produce some real heat to keep front windows clear.

Any opinions? Any help with finding 110V ceramic heater elements?

[Boreas]

Hello Mora,

Do you have Wal-Mart or Home Depot or any other American discount retailer near you in Finland? You may be able to get them to ship a complete heater to a store near you. Electric heaters here in Minnesota are pretty cheap Wal-Mart has two for under $25 US. I'm not an electrical engineer but, aren't electric heaters just big resistors? Could you hook two 220 v elements together in series to make it work at half the voltage? WiKipedia has the formulas if you search electrical resistance. It's too early in the morning (7:00 am) here for me to figure out. That's all I can think of to do. Good luck with your project.

[mora]

Thanks for the good wishes.

Unfortunately we don't have Wal-Marts of Home Depots here. We have some similar stores but those don't carry anything rated for 110V.

I'm no electrical engineer either, but if I hook two 220V heaters in series and apply 96V, they both run at half voltage if resistances are equal (48V per element, even lower amount of heat). Connecting them paraller gives both 96V, but it is still way under what I want.

I noticed I could open an account for some online service and get a "valid" US street address. I could order anything to that address and they would send all the stuff to me. But that costs even more than if x-mart would ship directly to me.

[vpoppv]

I don't know anything about anything, but it seems even a 220v ceramic heater should work fine in a 96v setup because of the whole "resistance increases as temperature increases" thing. Yeah, I'm a real electrical genius Anyway, here's a video of what Gavin did with a 220v heater (though he was running 144v, I think 96v should still work):

Installing the Heater

[mora]

Heheh. Thanks for the video link. I've read the whole conversion story and watched every video through. That's where I got the idea of ceramic heater in place of original heater core. If you take a look at the text under the video, at the very bottom he says one element delivers only "warm" air during cold mornings. He recommends the same thing as I think: a 120V (or 110V, hehe) element or two elements paraller. I think he means two 220V elements in paraller, but I'm going to use two 110V elements in paraller.

I also think that element doesn't work at its full power if lower voltage is applied. If so, element works like described (resistance increases as temperature increases and this limits current). If so, resistance of 1500W 220V element can be calculated. Same resistance with 96V voltage results in ~400W power. Boo.

Could someone of you living in the US get me pair of really cheap ceramic heaters, disassemble them and then send ceramic elements to me? Way cheaper than shipping two full heaters, which are going to get taken apart anyway.

[vpoppv]

Ok, this is perhaps where my lack of electronics will become apparent, but I thought that there was no internal difference between 110v and a 220v ceramic heater; this would be because it doesn't care how much voltage is going to it since the resistance varies based on the amount of heat produced rather than voltage. This would explain why, in contrast, coil type heaters have resistors in line, whereas ceramic do not. If however, there is a difference between a 110v and 220v ceramic heater, couldn't you compensate by using two in parallel 220v elements to be the equivalent of a 110v heater? Ok, I'm going to shut up now because people will start worrying for my life that I know so little and trust my life to an electrically powered car.....

[Piwoslaw]

Originally Posted by Boreas

Could you hook two 220 v elements together in series to make it work at half the voltage?

That's the first thing that came to my mind, but after some thought I understood that I got it wrong. Using two 110V heaters in series with 220V voltage would work, but not the other way around. But then, I'm just the next member here without too much understanding of electricity, who is telling Mora what won't work.

But here's an idea (don't know if it'll work): Someone with a 110V ceramic heater at home should check its resistance and post that along with the rated wattage. Then maybe Mora could find a ceramic 220V heater with similar resistance and try to use that.

Or someone who actually knows something about electricity could post so we don't all kill ourselves (and each other).

[mora]

Originally Posted by Piwoslaw

Or someone who actually knows something about electricity could post so we don't all kill ourselves (and each other).

Hehehe, yes. I'd prefer someone wiser chiming here too.

I can put two 220V in paraller. But I don't have space to put 4 of them paraller. I want 2x 110V. Lots of heat if necessary. Big amp draw too, heheh. But I think heater doesn't need to be on all the time when driving.

Resistance is very low when element is cold. Maybe too low to be measured. If element is heated to its full, resistance should be higher and readable. Touching the AC powered element with multimeter might be scary though.

I will definitely experiment with both 110V and 220V elements if I happen to get 110V one. Also if I used higher voltage, lets say 144V, I wouldn't have to worry that much about 110V elements anymore. But rising voltage isn't an option for me right now.

[hypermiler01]

.

[solarguy]

OK, here's the fact,

If you run any common electric resistance heater at half voltage (eg rated 240V, operated on 120V) you will get 1/4 of the rated wattage out, as heat. So, a heater rated at 2000 watts, operated at half voltage, will only produce 500 watts of actual heat.

Voltage matters. A lot.

So, good observation on your part, that running a 220V heater on 96V doesn't get you much. Less than 1/4 of rated wattage in fact.

Your original plan to get a 120V heater to operate on 96V is a good idea, you just have to find one.

Can't help you with that part, very sorry.

troy