Are heat pumps worth extra cost it EV Cars

Vegastare

Due ev from company shortly.  Out in all weathers and work away also.   You name it I travel through it.

Told heating drains battery quickly,  so heated seat etc in to help.  Plus heat car before you start off when on charge to get interior warm.  No mention of demisting windows etc. 

Forgive me for my total ignorance - I'll admit it, totally in the dark with it all.

Not even sure make yet.....

Is there a real benefit to getting one....thought see how it goes and could maybe get if required....or are they factory fit.

Any thoughts please

MeteredOut

Yes, they are a benefit, reducing battery drain and increasing driving range, but the actual benefit will depend on the make/model of car. 

If a choice of the same model of car with or without one, I would look to get the one with the heat pump, but it would come down to the additional cost versus those savings, which will vary by car. 

It may influence my choice of make/model too, but that's a more personal thing. I'd not chose a make/model just because it has a heat pump.

Arunmor

Anything that uses electricity will reduce your range.  Cold weather will reduce your range (EV and ICE).

uknick

Heat pumps are generally factory fit.  I would have said always, but I don't know if there are companies that now retrofit them as after market..

Are they worth it?  I can only speak for the BMW i3, I don't see why it should be significantly different for other cars, but the general view in the Facebook group was they gave about 10% extra in range.

With regard to using the heat pump, the benefits you mention, heated seats and heating the car before you use it, won't make use of the heat pump.  And, they should be standard functions on most EVs.

The heat pump is purely used to heat/cool the cabin air when driving. 

MeteredOut

uknick said:

Heat pumps are generally factory fit.  I would have said always, but I don't know if there are companies that now retrofit them as after market..

Are they worth it?  I can only speak for the BMW i3, I don't see why it should be significantly different for other cars, but the general view in the Facebook group was they gave about 10% extra in range.

With regard to using the heat pump, the benefits you mention, heated seats and heating the car before you use it, won't make use of the heat pump.  And, they should be standard functions on most EVs.

The heat pump is purely used to heat/cool the cabin air when driving. 

Not pre-heating the battery before driving? Or are you referring to the i3's heat pump here?

They are not (yet) standard on most EVs.

On-the-coast

Pretty marginal in UK climate (when cost of that option is taken into account). I don’t feel I got my money back in electric savings, though probably got a bit more range.  

My replacement arriving in a few months won’t have that option fitted. 

WellKnownSid

I'm in a similar position and have been surprised how many premium EVs do not have a heat pump as standard.

I strongly suggest you take a look at Bjorn Nyland's 1000km challenges - he takes them out in all weathers - it'll tell you far more about how good/bad different cars will be to live with when it comes to charging curves, quality of navigation system, real life behaviour on the road, etc in all weathers than any test drive you'll ever do.

I was surprised how little the lack of heat pump impacted the ID Buzz he tested even at -15 and below on his trip to the Arctic circle.  He had the cabin heat set to 22.5 degrees and was pulling about 5.5kW.  Even with a heat pump it probably wouldn't have been that much more efficient due to the reduced CoP at that temperature difference.

I reckon for the UK a heat pump would be more relevant due to the lower heat demand, but clearly not the slam dunk you might naturally think it is.

https://www.youtube.com/@bjornnyland

https://youtu.be/YggztC7naCU?si=zoroG_2oUNdGQj9L

facade

On my Citroen the heat pump is an integral part of the car, it could not be retro fitted. Saves some electricity, as a heat pump can approach 400% efficiency, depending on the temperature differential between hot & cold.

------- technical part ---------

The coolant (water) is pumped through the battery, inverter and motor to cool them, through the cabin heater to warm it then the radiator at the front to dissipate any excess heat. It also passes through a heat exchanger which is the condenser for the heat pump. There are various water pumps & valves to control whether the water goes through the main radiator under the bonnet, the heater or both. There are also valves to control where the refrigerant can go.

When in AC cooling mode refrigerant flows through the evaporator in the cabin, vaporises and cools the air by extracting heat from it. 

In AC heating mode refrigerant flows through the evaporator under the bonnet, vaporises & extracts heat from outside. Then in both cases the vapour condenses in the heat exchanger, passing the collected heat energy to the water.

The warmer water is then passed to the cabin heater or the radiator under the bonnet, depending on if the AC is heating or cooling.

There is also a resistive heater like a kettle to supply additional heat to the water for a fast warm-up and when it is very cold, and in heat mode the evaporator in the cabin is in circuit to dry the air when it is above freezing, so the efficiency isn't 400% as some heat is extracted from the cabin air, and then returned to it again via the water!

-------- main points -------

Pro: A heat pump saves energy, increasing the range in Winter (when you really need it as useful battery capacity drops off a cliff) They can also help increase battery efficiency by warming the cells when it is below freezing.

Con: It is massively more complicated than a simple cool only air con, and much more likely to have something go wrong, simply because there is more to go wrong.

The main difference you will notice compared to a petrol car, or an EV with just an electric heater, is that the air from the heater is never toasty warm, even on super maximum hotness.

As I mentioned, heat pumps work best with a low temperature difference between hot and cold, so the water never goes above about 35 Celsius (This is the same for houses with heat pumps, they have to have gigantic radiators compared to a conventional gas/oil boiler)

You get used to it, eventually......

Keep_pedalling

I don’t think they are worth it for the climate we get in the UK. I did not have one in my ID3 and did not bother with it in my current Skoda Elroq. If I lived in somewhere like Norway I probable would have had one fitted. 

Pre-heating the car before leaving home helps get both the car and the battery nice and toasty and clears the windscreen. I would say heated seats are a must have. When it’s cold I use the seat and steering wheel heater with minimum cabin heat and that that does not put too much drain on the battery. 

Ectophile

I'm surprised they don't come as standard on most EVs these days.  The heat pump is really only the aircon running in reverse.  My Renault Zoe came with a heat pump as standard; it was never an option.  And it's not exactly a high-end car.

One disadvantage I have found is that you can't have the aircon and heating on at the same time.  On a cold damp day, you can find the windscreen misting up even with the heater on.  With an ICE car, you can turn on the aircon and heater at the same time, and the aircon dehumidifies the cabin.

With a heat pump, the only viable option is to crank the fan and heating up to maximum.  Which is unpleasntly noisy.

facade

Ectophile said:

I'm surprised they don't come as standard on most EVs these days.  The heat pump is really only the aircon running in reverse.  My Renault Zoe came with a heat pump as standard; it was never an option.  And it's not exactly a high-end car.

One disadvantage I have found is that you can't have the aircon and heating on at the same time.  On a cold damp day, you can find the windscreen misting up even with the heater on.  With an ICE car, you can turn on the aircon and heater at the same time, and the aircon dehumidifies the cabin.

With a heat pump, the only viable option is to crank the fan and heating up to maximum.  Which is unpleasntly noisy.

Amazingly, for all it's faults (and they are legion) My Citroen e-C4 does run the evaporator in the cabin to dry the air when the heater is on until the outside temperature drops below zero (when the air will be dry anyway as all the moisture will have frozen out) So it extracts heat from the incoming cabin air, and pushes it into the water to flow into the cabin again, so some of the heatpump capacity is used condensing any water in the air.