EV Liquid Heating Revisited

[bennelson]

Hey Everyone!

It is cold again, and heat in EV's seems to be a perennial topic.

A while back, I was kicking around some ideas for how to take some heat with me in my Electro-Metro, getting the power from a wall outlet instead of taking it from the batteries.

Last winter, I ended up with an oil-filled electric radiator behind the passenger seat. With it on a timer (and an extension cord out the window) it turned on in the morning for a while before I went to work, and I could leave in a nice warm car.

I have still always wanted to find some good way to re-use the existing, liquid-powered, heater core in the car.

If I bought a circulating coolant pump, like this one:

A Kats 1500 watt circulating model ($40 on Amazon.com) I could hook it up to the original coolant connections on the firewall of my car.

I would then rig the blower fan so that it would automatically come on when the coolant heater was running. Most likely, the Heating controlls would just be left to "defrost" to circulate the warm air across the windshield and into the car.

With an EV system voltage of 120 or 144V, the heater could run off EITHER WALL POWER OR BATTERY POWER. If a couple gallons of coolant were added in some sort of thermos, at least a little heat could be brought with, in the form of the pre-warmed coolant.

Any suggestions or caveats as to how to best make a system like this work?

-Ben

[MetroMPG]

One thing to consider: if that heater is like mine, it's convective, not mechanical circulation. May affect effectiveness.

[NiHaoMike]

Buy a water heater element and some galvanized pipe and fittings. It would be much cheaper.

[Christ]

A fishtank pump would likely flow enough water to keep heat in the engine compartment, Ben. A resistive heating element, as NiHaoMike suggests, would probably be sufficient to heat the fluid. I think you can do this whole project for $50.

Both parts are 120V as well, so you could run them off your pack voltage, I think. The fishtank pump, maybe not, though. If you can't use it, a 12V fuel pump might work out for you instead.

[bennelson]

And don't worry, I know enough to bypass the radiator as well.

[Christ]

ROFL. Yeah...

[Silveredwings]

How about just an off-the-shelf interior heater (probably could find it cheaper): Kat's 37100 Automotive Interior Heater with 900 watts power 120 Volts!

Or if you're feeling lucky, make one out of a ceramic heater element where the old heater core was (see Jerry's excellent EV site EV Weblog: Bring on the Heat).

[Ryland]

How about a small tank style hot water heater, something like a 3-5 gallon under sink water heater, it would be an insulated tank, heating elements for 120v and if it has two then you could put a 12v one in as well, the only draw back that I see is the price and the space it would take up.