Electric car heater

[PeterH]

A quick question I'm sure our knowledgeable experts can answer staight away.

How does the heater work in an electric car? I guess Air Con would just have an electric motor to drive the pump but with no engine cooling, air or water, what heats the heater? An electric element? but that would surely gobble battery power.

 

[Mjit]

Either an electric element or just the the air con in reverse.  Should be possible to reclaim heat generated by the batteries, etc but doubt that's done in most cases.

[Rabbit]

Programme on Radio 4 regarding this and other queries with electric cars. The 'EXPERTS' suggested dressing for the colder weather as we are too used to heaters etc. You all remember those pictures on TV of cars stuck for hours and oversight etc on snowed up roads, well, if you have an electric only car there will be loads of dead, stiff, corpses to clear up because the occupants could not get warm and had not got the gear to walk to civilisation! Already more accidents are being reported with electric cars not putting headlights etc on as the cells are low on juice. YES, I know I should have charged it up but I live on the 40th floor of a high rise and  . . . . etc etc, you now what I mean. Must got a flattish battery on my Dolly but I do know that once charged  up my petrol engine will keep me warm and cosy in the snow etc . . . . . 

[Rabbit]

P.S I am sure my fingers do not make all those MISTAKES but I think you get my drift! 

[PeterH]

 

33 minutes ago, Mjit said:

Either an electric element or just the the air con in reverse

How does air con in reverse work?

[Colin Lindsay]

This is because we're all so unreasonable here and live in a colder country. Other countries can cope fine, as they probably don't need a heater, but we're just so demanding!

Seriously though it's probably an electric element but of course it gives less range when in use.

We'll go back to the days of having a large woolen blanket on the back seat for when it gets cold. You'll be able to spot electric car drivers once the cold spell starts.

[NonMember]

13 minutes ago, PeterH said:

How does air con in reverse work?

The same as "ground source heat pumps" and others.

Air-con works the same way as a fridge. The working fluid is pumped around a closed circuit between a "condenser" and an "evaporator". In the former, the fluid gets compressed enough to liquefy. This produces a significant heating effect, making the condenser hot. Then, in the evaporator, the fluid is allowed to expand rapidly, absorbing heat and vaporising it. Thus the evaporator gets cold. The overall effect is to "pump" heat from the area round the evaporator to the area round the condenser.

In a fridge, the evaporator lines the fridge and the condenser is on the back. In an air-con, air is blown over the evaporator and the condenser is outside. In a heat pump heating system, the evaporator is outside and the interior air is blown over the condenser.

[JohnD]

1 hour ago, Rabbit said:

Programme on Radio 4 regarding this and other queries with electric cars. The 'EXPERTS' suggested dressing for the colder weather as we are too used to heaters etc. You all remember those pictures on TV of cars stuck for hours and oversight etc on snowed up roads, well, if you have an electric only car there will be loads of dead, stiff, corpses to clear up because the occupants could not get warm and had not got the gear to walk to civilisation! Already more accidents are being reported with electric cars not putting headlights etc on as the cells are low on juice. YES, I know I should have charged it up but I live on the 40th floor of a high rise and  . . . . etc etc, you now what I mean. Must got a flattish battery on my Dolly but I do know that once charged  up my petrol engine will keep me warm and cosy in the snow etc . . . . . 

Whereas running the engine to keep warm in a snowed-in car is good way to achieve loads of dead, warm, corpses, from CO poisoning!    The exhaust gas will  recirculate under the car to the air intake, and CO is odourless, deadly and very quick.

In America that regularly gets heavy snowfalls, such deaths are wel-known, but not enough.  See: https://www.nbcwashington.com/news/local/carbon-monoxide-poisoning/71433/

If stopped by heavy snow, always get out and check that the exhaust is clear, and repeat if snow is falling.   You cannot rely on the heat of the tail pipe to keep it clear.

John

[Colin Lindsay]

BTW don't bother buying one of these for supplementary heating in any car, electric or otherwise:

You'll get more heat from flatulence. £7 from eBay as a stocking filler to defrost the Freelander more quickly than the diesel engine will. It's total rubbish. Global Warming will heat up more quickly.

 

 

 

[68vitesse]

3 hours ago, Colin Lindsay said:

BTW don't bother buying one of these for supplementary heating in any car, electric or otherwise:

You'll get more heat from flatulence. £7 from eBay as a stocking filler to defrost the Freelander more quickly than the diesel engine will. It's total rubbish. Global Warming will heat up more quickly.

 

 

 

Are you saying global warming will be a good thing.

Regards

Paul

[dougbgt6]

Colin,

Doesn’t the heat come out the slots? To defrost it’s the wrong way around! 🤣

db

[Peter Truman]

Was it VW that used to use a Petrol Heater, Oh Petrol Heater in an Electric Car Ooh!

I always queried what happens to the elect cars batteries in extremes of weather ie how their performance was affected by cold and hot weather eg Canada and Australia (also both countries have great distances to traverse), an article by CTEC (BU-502: Discharging at High and Low Temperatures)  covering lead acid and Lithium generally advise optimum performance between 20 and 27C, at -18C it will deliver by as low as only 50%. and a battery operating at 30C the cycle life is reduced by 20% & at 40C the life cycle is reduced by a whopping 40%.

This made me smile, interestingly both NiCad and Li-ion can operate down to -40C but at a reduced discharge rate, but charging is out of the question at this temperature.

above is selective for guide only and better people than me might understand the full context of the article.

Peter T 

[mpbarrett]

We have a golf GTE plug in Hybrid.

In the summer we get about 30 mile range out of the battery, this time of the year it drops down to 23 miles (fully charged) as the battery is less efficient in cold weather. If we switch off the heating we gain an extra 3 or 4 mile range!. In the summer turning off the A/C makes no difference to the range. The range indicator is only an approximate measure of the battery state, even when it show 0 miles the car will still switch to electric power. Shame there is not a better measure of the battery state.
So a lot of energy from the battery is used to heat the car, the upside is that you can sit in the car in a traffic jam with a nice warm car and no engine running (vital around the chocked roads of Cambridge).

I don't know how the heating or A/C systems work (or the dual clutch gearbox or how it decides when to use the electric or petrol engine, or even if it has a normal battery) its frustrating not to know in detail how it works! Don't think Haynes have written a manual for it yet....
I think that's why I like working on the Herald, everything is understandable.....

mike

 

[AndyTV8]

11 hours ago, Peter Truman said:

Was it VW that used to use a Petrol Heater

 

I think the VW Beetle is the one you are thinking of

....... Andy 

[rlubikey]

18 hours ago, Mjit said:

Either an electric element or just the the air con in reverse.

18 hours ago, PeterH said:

How does air con in reverse work?

17 hours ago, NonMember said:

The same as "ground source heat pumps" and others.

Air-con works the same way as a fridge. ...

And, due to the magic of thermodynamics (which I've STILL not quite got my head around) this can operate at seemingly MORE than 100% efficiency. In other words, for 1kW electric energy in, you can get 3kW or 4kW or more heat energy out to warm your car, house, whatever. This means that a heat pump is way more efficient than just a simple heating element. If you have air-con, running it in reverse for heating is a no brainer.

My ex-colleague bought an M1 BMW and was surprised to find it gave almost instant cabin warmth - not toasty heat, just warmth. BMW had added the extra valve to reverse the air-con and warm him before the heat of the engine came on stream.

But yes, when you all have electric cars, long johns and vests and hats will come back into fashion - for those with long commutes anyway!

Cheers, Richard

[Bfg]

My daily driver, a Chrysler Grand Voyager with leather covered seats, has very effective seat warmers. These are individually switched and have two settings. I wouldn't have thought they use very much power compared to trying to heat the volume of interior encompassed by glass.  Similarly I have heard of heated steering wheels.  It wouldn't be much of a stretch of imagination to have heated floor mats. And for emergency use ; to have a space-blanket with electric element. I'd guess such things are readily available in places like Canada.  

Pete.

[dougbgt6]

12 hours ago, Peter Truman said:

Was it VW that used to use a Petrol Heater,

My dad had a VW fastback when he lived in Seattle, it had a petrol heater. Mother loved it, freezing to sauna in 30 seconds, but it knocked a big chunk off the MPG. Dad shipped the car back to the UK when they came home. Before it went to the scrappie he removed the heater and passed it on to his brother who lived in Scotland. Uncle installed it on his Vauxhall 101 estate. My cousin still has it, but not installed on anything currently.

Doug

[Colin Lindsay]

15 hours ago, 68vitesse said:

Are you saying global warming will be a good thing.

Regards

Paul

Every time I try to see through totally frozen windows - yes. On warm nights when I can't sleep - no. When I listen to sanctimonious b***** on TV preaching night after night - definitely.

15 hours ago, dougbgt6 said:

Colin,

Doesn’t the heat come out the slots? To defrost it’s the wrong way around! 🤣

db

That's not mine, just a pic of one fitted. There are two settings: icy cold, and barely-warm breath. You really have to strain to feel any heat in the blast at all.

[68vitesse]

20 minutes ago, Colin Lindsay said:

Every time I try to see through totally frozen windows - yes. On warm nights when I can't sleep - no. When I listen to sanctimonious b***** on TV preaching night after night - definitely.

Know what you mean about tv sanctimonious b****** , I was on the same holliday as David Bellamy a few years ago, very nice bloke, he said his tv career ended when he questioned the party line on global warming.

Regards

Paul

[dougbgt6]

Heard an interesting theory on the TV this morning that I first read in the New Scientist 10 years ago. Takes a while fore the meja to catch up 

A consequence of global warming will be that the Gulf Stream diverts and Iceland becomes subtropical. Unfortunately UK and the island of Ireland then become very much colder places, effectively swapping climates with Iceland. We forget that London is on the same latitude as Moscow.  😨

db

[Chris A]

4 minutes ago, dougbgt6 said:

Heard an interesting theory on the TV this morning that I first read in the New Scientist 10 years ago. Takes a while fore the meja to catch up 

A consequence of global warming will be that the Gulf Stream diverts and Iceland becomes subtropical. Unfortunately UK and the island of Ireland then become very much colder places, effectively swapping climates with Iceland. We forget that London is on the same latitude as Moscow.  😨

db

Seen that many times in the past, even before climate change became a fashion item, Britain is far too warm for the latitude. No Gulf stream hello penguins on the Thames.🐧

[Colin Lindsay]

I know it's a genuinely serious thing, and we're going to need to do something asap, but I just think we're the ones footing all the bills and having all the restrictions and guilt placed on us while China, India, Brazil, and the like continue to belch out pollution and do absolutely nothing about it. Next thing, we'll be paying vast sums of money to those countries to cut down emissions; money we could use on our own infrastructure and welfare.

Add Philippino volcanoes and Australian bush fires and my little car exhaust or my wood-burning stove seems to be small fry indeed.

[poppyman]

Is it me or since we have been doing more to address global warming it's never stopped raining.  The bush fires in Australia according to the bushmen are only due to the fact they have been stopped burning the bush in a controlled way to make fire breaks.

Tony.

[Pete Lewis]

ive got this idea that the clearer the sky the hotter it going to get 

what with a low bright sun and prince philip syndrome you now cant see where youre going

then throw in daft headlamps full of stray light its all getting   difficult

bring back the smogs   remember them !!!  pea supers   , not really  but   whee is this all going to end  

then blow a few volcano's and the Chinese  and we  are just spit in the ocean  .

and there nowt on TV while i wait for me pills and a cuppa 

Pete

[JohnD]

A Haynes for working on EVs?   I don't think so!  Not soon anyway.   Afrined runs an indie garage and has "been on a course".    The H&S provisos are extraordinary, for instance anyone working on the electric side will do ONE-HANDED!     So they can't get 400V across both arms.

John