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Battery cooling? Cabin ventilation? A/C condenser? Front brake cooling?


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Yeah, the front grill that's low down provides airflow for the battery cooling system. There's also an extremely loud fan for it which comes on occasionally, at high temperatures while driving or at more modest temperatures while supercharging.

There's also the issue of cooling the electric motor.


Not cooling their battery is a showstopper in my opinion. Great car otherwise.

Cars have air-conditioning, heaters, and openable windows.

In my opinion, proper winter-ready BEV should have a heat pump for heating the interior and battery, battery insulation to reduce uncontrollable loss of heat from battery, rotary heat exchanger to further save on heating ventilation air and double-pane windows to reduce losses from interior.

Double-pane windows would increase weight by about 5%, while decreasing losses through windows about 5x, iirc.


That can be handled with pre-cooling your car.

I wonder about engine cooling. The radiator is at the front to catch as much of that air flow as possible. You don't really want to block it.

That's easy - the expanding gas!

Releasing pressurized gas absorbs heat so simply running the released gas through a set of A/C coils would provide indirect A/C or you could merely vent the "exhaust" (it is air, after all) into the passenger compartment since that "exhaust" should be very cold.


And a heated steering wheel.

I thought GP was referring to generating heat for HVAC, which is an interesting idea. I assume one challenge would be getting the warmth from the brakes to the cabin.

What's done for cooling/heating? Does this require a pretty temperate environment, or is it relatively well sealed?

Vehicles leak like sieves unless you seal them up yourself, which could be a catastrophically bad idea if exhaust starts to find its way into the vehicle while it is running.

Aside from opening windows or bundling up and shivering, your cooling/heating options are either typical house HVAC appliances, or extending the functionality of the onboard heating and cooling and hoping that you bought a diesel, which are much more tolerant than gasoline engines of idling all day. Which brings me back to the risk of exhaust gasses when the passenger compartment is mostly sealed.

For electrical power to run appliance-type HVAC, you could use a small generator.


Condensation is a show stopper in a car. In a van you can install screened vents.

For something that generates a lot of heat when bringing the car (and air!) velocity towards zero, you really need to have forced air cooling available.

Why not resistively heat that cooling loop? Or release it to the cabin? Turn on the de-frost?

I kinda wish my ICE car would crank everything up while engine-braking down a hill to reduce brake and fuel use.

It shouldn’t be that expensive...


intake air preheating and cold return water preheating come to mind

Why not 2-4 kw to heat the cabin really fast when it’s cold? Pre-heating the cabin instead of the brakes would save cabin heating energy later.

> turning on the air conditioning

You could cool it a bit with a Stirling engine and get a little more power from the overheated interior. ;-)


A condenser column would need to be cooled. Even a passive radiator adds weight.

Another step in the engine cycle can cool and condense the water vapor to liquid, and extract additional energy from the exhaust. The weight of the required additional engine parts, and the cooler in particular, tends to erase all the actual benefit in an automobile. Cargo ships and train locomotives could do it.


I think there are still some reasonable solutions:

* smaller resistive heaters with higher airflow

* dump the heat into resistively heating the battery. Then use the battery again!

* Just use disk brakes to achieve the same feel. Which is also, basically, dumping heat.

Remember that the problem to solve is that a car shouldn't drive differently at different temperatures...


more powerful compressor, bigger heat exchanger, measures against snow and frost, better defrost implementation to avoid stop heating.
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