"Morex Support" wrote in message
able.rogers.com...
Fatal Error.
The heating element is resistive. 120V 2KW element is approx 7 ohms.
Reduce
voltage to 24 v and current draw drops to 3.5 amps. Power is not a
constant.


I am sure that Larry wasn't suggesting that a 120 volt heating element be
used at 12 volts. What he was suggesting is that IF a 24 volt equivalent
device could be found, then it would draw 83 amps.

Oh, and by the way, your example is way off also. In most cases, heating
elements have a dramatic increase in resistance as they heat up. The element
in question may have a resistance of 7 ohms when it is dissipating 2KW, but
if you drop the voltage the resistance will drop also.

This resistance change is even more dramatic on a light bulb. Take a low
wattage light bulb and measure the resistance when it is cold and you may be
surprised! This is why cutting the voltage in half to incandescent lights
does NOT cut the current in half!

Rod McInnis

"Bryan B" wrote in message
...
We use both 12 and 24 systems.


Just out of curiosity, who is "we" ?

Rod

On Thu, 15 Jan 2004 13:09:01 GMT, Brian Whatcott
wrote:

I knew what Larry intended: why didn't you?

Brian W

Now I can stop shaking my head and wiping my glasses....(c;

hi
stuff made for trucks here in the uk are 24v..


"misia" wrote in message
ail.from.there...
On my new boat I will have a powerfull 24VDC battery bank charged by a
diesel generator and auxiliary sources.

I did a bit of search but couldn't find much- are there any 24 VDC
appliances such as cooker/oven, fridge, AC and water heater you could
recommend?

I know I can run standard items through power inverter but I would
prefer not to do it for the sake of reliability/efficiency/cost. I want
to go totally electric (no gas)

Regards Mi

Rod McInnis wrote:

the old Volkswagon Beetles used a heat exchanger off the exhaust manifolds
to heat the car! It was actually pretty nice on cold mornings, as the
heater worked almost instantly after starting the car.

Woah! I had one of those Beetles way back then. It leaked CO so bad it nearly
killed me. I would worry about any heating system that utilizes a heat
exchanger off the exhaust manifolds.

Larry Weiss
"...Ever After!"
"a little after..."

If you recall the heritage of the Volkswagon, it's no surprise it tried to
gas you.

-W


"Larry Weiss" wrote in message
...

Woah! I had one of those Beetles way back then. It leaked CO so bad it
nearly
killed me. I would worry about any heating system that utilizes a heat
exchanger off the exhaust manifolds.

Larry Weiss
"...Ever After!"
"a little after..."

Clams Canino wrote:

If you recall the heritage of the Volkswagon, it's no surprise it tried to
gas you.

-W


"Larry Weiss" wrote in message
...

Woah! I had one of those Beetles way back then. It leaked CO so bad it
nearly
killed me. I would worry about any heating system that utilizes a heat
exchanger off the exhaust manifolds.

Larry Weiss
"...Ever After!"
"a little after..."





I have a vague memory of my Model 411 (well, something like that)
burning raw gasoline to make heat. But perhaps my memory is playing me
tricks.



--
Email sent to is never read.

The original responder should have said you got 'instant heat' if you lived
in a moderate climate. In Alaska, I had a "gas heater" in my bug and my VW
van too. It was the only way to get enough heat out of those air-cooled
vehicles to defrost the windows, let alone give you more than just a cold
blast of air through the vents.

In the bug, the gas heater sat under the hood (trunk in front). Quite an
interesting heater too. It had one 12-volt motor, which spun the air
blower, a fuel pump, and a cam-driven set of points. The air blower blew
air over a combustion chamber and into the car's heater vent system. The
fuel pump pumped fuel out of the gas tank through an atomizing nozzle into
the combustion chamber. The set of points ran switched-DC through a regular
automotive coil to produce a high-voltage pulsed DC that continually sparked
a huge spark gap (about 1/4") on a special spark plug. Pretty simple rig.
Air came into the combustion chamber and the exhaust went out a pipe into
the left front wheel well. If you had the wheel turned hard left and took
too long getting going, you'd smell burning rubber from the tire standing
under the exhaust too long. The heater didn't get hard to start until it
was about -20 F or so, but it would usually start eventually (after
producing a lot of black smoke). The gas heater in the van was a bit more
sophisticated but used the same principles of operation, but the air came in
from inside the van and out an exhaust under the van. The heater was
mounted under the driver's seat.

Brian

--
My boat project: http://www.advantagecomposites.com/tongass


"Harry Krause" wrote in message
...
Clams Canino wrote:

If you recall the heritage of the Volkswagon, it's no surprise it tried
to
gas you.

-W


"Larry Weiss" wrote in message
...

Woah! I had one of those Beetles way back then. It leaked CO so bad
it
nearly
killed me. I would worry about any heating system that utilizes a heat
exchanger off the exhaust manifolds.

Larry Weiss
"...Ever After!"
"a little after..."





I have a vague memory of my Model 411 (well, something like that)
burning raw gasoline to make heat. But perhaps my memory is playing me
tricks.



--
Email sent to is never read.

On Mon, 19 Jan 2004 18:13:11 -0500, Harry Krause
wrote:

I have a vague memory of my Model 411 (well, something like that)
burning raw gasoline to make heat. But perhaps my memory is playing me
tricks.

=================================

Not sure about the 411 but on the Beetle the gas fired heater was an
optional (and popular) extra. It used to fit about where the glove
compartment should have been if my memory is correct. One of my
colleagues when I worked at Cornell U back in the 60s was a bit of a
VW fanatic. He was always collecting heaters and other accessories
from where ever he could find them.

"Morex Support" wrote in message . cable.rogers.com...
Fatal Error.
The heating element is resistive. 120V 2KW element is approx 7 ohms. Reduce
voltage to 24 v and current draw drops to 3.5 amps. Power is not a constant.

I don't recall anyone suggesting to run a 2kW, 120V heating element
directly off of 24V. The question was to run an inverter on 24V to
make 120V, or to obtain a 2kW, 24V element (0.288 ohms).

%mod%