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914World.com _ 914World Garage _ 12 Volt heaters

Posted by: Tom Nov 7 2005, 05:36 PM

Hey, has anyone ever tried to use these small heaters to keep the wind shield defrosted and to provide a little warmth on those chilly mornings? If these would work, no more heat exchangers and ducting. Wonder what we could lose in weight and what could be run through the tubes instead of hot air?
Just wondering,
Tom

Posted by: lapuwali Nov 7 2005, 05:49 PM

It has been asked, but as far as I can remember, there's no definitive answer. The heat these things put out is pretty small, unless you get a big unit that draws a lot of power. The stock 914 alternator only puts out 55amps, and the wiring to the dash area is mostly sized to carry the (heavy) loads imposed by the lights, without a lot of headroom.

So, mounting a big one so it blew into the side tubes wouldn't be the "hot" ticket (sorry), but mounting a smallish one inside the fresh air box below the windscreen might work. You'd really want to run a dedicated power wire of 10-12g and a relay. It doesn't take much to demist the screen, but you're not going to keep yourself all that warm with such a setup.

Posted by: SirAndy Nov 7 2005, 06:01 PM

QUOTE (Tom @ Nov 7 2005, 04:36 PM)
Just wondering

get one of them gasoline burning heaters (for VW-bus and such).

*MUCH* better heat ...
Andy

Posted by: davep Nov 7 2005, 06:05 PM

Our company sells the little heaters. They draw about 15 amps and put out nearly 200 watts. Not enough to notice any real heat. Gimmicks only, but don't tell my boss I said so.

Far better to spend money on SSI heater boxes and a full factory system, because it really works. Even here in Canada I found it worked very well for the many years the car was my only driver.

Posted by: Bleyseng Nov 7 2005, 06:07 PM

a factory set up with SSI HE's will blast you out on cold days in short order. Helps to have a working thermostat too....

Posted by: bd1308 Nov 7 2005, 07:07 PM

working thermostat i not have. but the heat is Awesome! where would you put a VW gas heater?

b

Posted by: smontanaro Nov 7 2005, 07:57 PM

QUOTE (bd1308 @ Nov 7 2005, 07:07 PM)
where would you put a VW gas heater?

It was up front somewhere on my '67 911S. Made by Eberspacher I believe. Would that have even been an option on 914s?

Skip Montanaro

Posted by: Mueller Nov 7 2005, 07:58 PM

QUOTE (bd1308 @ Nov 7 2005, 06:07 PM)
where would you put a VW gas heater?

b

......front trunk...I think Bowlsby posted pictures of a factory install..

Posted by: iamchappy Nov 7 2005, 08:33 PM

Depends on how much heat you are looking for.
I used this in my car last fall at temps below freezing and was surprised on how well it worked.
I dont drive my car during the winter here in Minnesota but the electric one worked fine at temps below freezing. It throws enough heat to keep the cabin warm and kept the windshield clear.

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Posted by: roundboy914 Nov 7 2005, 09:13 PM

Where did you buy that one from?

Posted by: East coaster Nov 7 2005, 09:36 PM

Somebody install one of these so I copy from you!

http://cgi.ebay.com/ebaymotors/UNIMOG-PINZGAUER-M-35-M-151-MULTIFUEL-HEATER_W0QQcmdZViewItemQQcategoryZ33548QQitemZ8012950620QQrdZ1QQsspagenameZWDVW

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Posted by: Tom Nov 8 2005, 09:10 AM

To iamchappy,
Yes that's what I was talking about. I don't plan to be driving my 914 in really cold weather. Here in Washington when it is cold it is usually also raining. Not good for a 914. Where did you get this and is it powered by the cig liter?
Thanks for the reply's

Posted by: jsteele22 Nov 8 2005, 10:17 AM

I'd stay away from electric on basic principles. As mentioned, you need a lot of current to get a little heat. The one davep mentioned draws 15 amps and since P=V*I, thats 12*15=180 Watts, which isn't much -- about the same as 3 people generate just sitting around.

For comparison, a dinky little hairdryer is about 1200 watts. If you feel this would be enough heat, don't forget that that (electric) power is coming from somewhere. The alternator has to take power from the engine to make A/C power, which has to be rectified. The efficiency is pretty dismal, maybe 50-60%. So with 746 Watts = 1 HP, you end up using around 3 HP, assuming your alternator could provide an extra 100 amps, which it can't.

The beauty (?) of conventional heat in air- or -water-cooled cars is that the heat is already being produced for "free", all you need to do is move it to the cabin.

One way to solve the heat problem without all that bothersome plumbing (J-tubes, flapper boxes, etc.) and without having to sacrifice valuble trunk space for a gas heater, would be to ditch the passenger seat (you are single, right ?) and stick in a propane barbeque grill. They're simple, reliable, and spare parts are easy to come by. And imagine the savings on road food !

Posted by: davec Nov 8 2005, 01:39 PM

I installed a 12 volt hair dryer on my defrosting tube, ran 12 gauge wires, added a relay, and also put a ceramic heater (same one as previously posted), with the same wiring, under the dash. I also upgraded the alternator.

The ceramic heater didn't last (too much vibration) and did not produce enough heat for a fall New England night.

The hair dryer can only be used for short periods due to overheating.

I have a brand new electonic ignition Eberspatcher gas heater for sale, as I never mounted it. I was going to put it in the front trunk, but opted to spent heat money for a Fuel Safe fuel cell instead.

Mike D and I were toying with the idea of running an oil cooler in the heater tubes, or under the seats, but neither of us drive in the snow anymore, at least not while sober.

Contact me offline if interested in the gas heater, at dave@rennlist.net.

Posted by: Mueller Nov 8 2005, 02:05 PM

QUOTE (East coaster @ Nov 7 2005, 08:36 PM)
Somebody install one of these so I copy from you!

http://cgi.ebay.com/ebaymotors/UNIMOG-PINZGAUER-M-35-M-151-MULTIFUEL-HEATER_W0QQcmdZViewItemQQcategoryZ33548QQitemZ8012950620QQrdZ1QQsspagenameZWDVW

I just bought one

Hope it doesn't melt my carbonfiber hood

Posted by: goose2 Nov 8 2005, 02:14 PM

this is how we heat our cars in Oregon:

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