Heat pumps

eagerv

Interesting little video, talks about the ID.3 heat pump.

https://www.youtube.com/watch?v=qQR9e5BqvWo

KCross

eagerv wrote: »

Interesting little video, talks about the ID.3 heat pump.

Based on that it seems its running at higher pressure and is more efficient. Real world tests will be interesting alright. No doubt Bjorn will have a test for it in their -15°C temps!

Pity we wont have it by default though!

[Deleted User]

liamog wrote: »

That depends entirely on the refrigerant used. Heat pumps do not inherently stop working below 5C. The ID.3 heat pump uses a refrigerant that has a lower operating temperature which reportedly works to below -25C. Heat pumps are used for domestic heating in Scandinavian countries so it's a question of engineering the specific heat pump instead of a generalisation.

Domestic heat pumps are much larger and can work more efficiently at lower temps, the HP in an EV is tiny by comparison and there is no real benefit in todays EVs with 300+ km range, as I said, I'd rather pay for driver aids than to loose maybe 5 km on my commute in winter if even.

If I had a 64 Kwh ev for instance, there is no benefit to having a heat pump for my daily commute or I expect for most People.

And the only way as I said earlier to know the real benefit of having a HP in a car is to have a separate power monitoring system on the hp and electric heater but for most driving needs today with 60 odd + Kwh batteries there is no need for a HP.

liamog

Deleted User wrote: »

Domestic heat pumps are much larger and can work more efficiently at lower temps, the HP in an EV is tiny by comparison and there is no real benefit in todays EVs with 300+ km range, as I said, I'd rather pay for driver aids than to loose maybe 5 km on my commute in winter if even.

As I've said, totally depends on your use case, you are the first to shout about how the REx allows you to skip chargers, it could very well be the case that a heat pump means you don't need to charge mid journey on a regular trip in winter months.

Personally it's an option that I would pick, as I'd benefit from it exactly during the times I'm most worried about range. Winter travel on longer motorway journeys.

KCross

liamog wrote: »

Personally it's an option that I would pick, as I'd benefit from it exactly during the times I'm most worried about range. Winter travel on longer motorway journeys.

Would you pay €1k+ for it?

Hefty price for what it gives you in a long range EV. I'd rather give Ionity their 79c/kWh and charge up for an extra 3-5 mins!

[Deleted User]

liamog wrote: »

As I've said, totally depends on your use case, you are the first to shout about how the REx allows you to skip chargers, it could very well be the case that a heat pump means you don't need to charge mid journey on a regular trip in winter months.

Personally it's an option that I would pick, as I'd benefit from it exactly during the times I'm most worried about range. Winter travel on longer motorway journeys.

There's a massive difference in paying for the convenience of avoiding public chargers altogether + the increased charge times with a cold battery, not having to reduce speed etc than paying 1000 Euro's or close to save maybe 25-20 Kms..... the Rex can go for may more kms than a HP would allow as long as there is petrol.

[Deleted User]

KCross wrote: »

Would you pay €1k+ for it?

Hefty price for what it gives you in a long range EV. I'd rather give Ionity their 79c/kWh and charge up for an extra 3-5 mins!

Absolutely + the id.3 will hopefully have a decent charging curve which will hopefully result in decent charge times. Cold battery charging is another matter of course.

liamog

KCross wrote: »

Would you pay €1k+ for it?

Yes it's an option I would take, as I've said numerous times, and for the reasons I've indicated, I have a preference for the winter range staying closer to the summer range.
Your argument can be used for why bother buying the 64kWh Niro over a 39kWh, or any car that has a choice of battery.

At the end of the day it all comes down to value per km of range, and how often you will need to use that range.

KCross

liamog wrote: »

Yes it's an option I would take, as I've said numerous times, and for the reasons I've indicated, I have a preference for the winter range staying closer to the summer range.

We all have that preference!

Its the value proposition.... €1k+ to satisfy a few journeys.
Even on those journeys you may not be inconvenienced as you might have been stopping for a DC charge anyway so an extra few mins isnt going to matter much.

Each to their own I guess.

liamog wrote: »

Your argument can be used for why bother buying the 64kWh Niro over a 39kWh, or any car that has a choice of battery.

That's very different.

Not having the range 24/7/365 is very different to not having it on some occasions in winter.

And on those occasions its only a few extra mins on the charger to make up the difference. It not like it means sitting at a DC charger for an extra hour.

Horses for courses here and I'd rather have the HP too but no way is it worth it to me at €1k+ and I would be a regular long motorway user.

I might change my tune when I get to test drive the ID.3!

liamog

€3,000 for 80km of range in summer (ID.3 Pure vs Pro) which could be about 50km in Winter
or
€1,000 for 0km of range in summer (ID.3 Pure with HP) but is about 35km of extra range in winter.

It's an interesting conundrum
Numbers from ev-database.org so speculation!

[Deleted User]

And all that's assuming you save 30 Kms at all with the HP as I said, heaters cut in and out and you can't accurately measure this extra gain in efficiency without the proper equipment, in other words, without exact data as in power consumed by the heating system with HP and without HP there is no way to know the benefit, or not, of having HP or not.

The colder it gets the less efficient they are.

Yes, I too would rather save the money or spend it on better stereo or driver aid, much more useful, chances are you'd have to stop anyway for a charge.

liamog

A study carried out by Korea’s Ministry of the Environment on the Hyundai Kona Electric and Kia Niro EV found that the heat pump significantly reduced battery consumption in cold conditions. When each car was driven in temperatures of -7°C (19°F) with the HVAC system activated, they were able to maintain 90 percent of their driving range compared to journeys undertaken at an ambient 26°C (79°F) – setting a new benchmark for other EVs. By contrast, many EVs offered by other manufacturers saw their total electric driving range drop by between 18 and 43 percent under the same test conditions.

https://thekoreancarblog.com/2020/06/10/hyundai-kia-turn-up-ev-efficiency-with-new-heat-pump-technology/

[Deleted User]

Sure, winter range by non Korean electrics is terrible lol.

It’s not just heater, range is reduced by the denser cold air and reduced battery capacity due to cold battery add to that a windy Irish climate and wet roads will make a much greater impact than having no heat pump.

I might see a 20 km performance hit in the i3 in winter but that’s due to a combination of the above not because I don’t have a heat pump.

KCross

I think VW's implementation is doing this also, i.e. scavenging heat from the power electronics, which makes sense.

I dont think the 1st gen cars, like the Leaf, do this at all with their heat pumps so that will help improve efficiency.

liamog

We just need to get Mad_Lad into a car with decent heat pump and you'll be singing it's praises on every thread!

[Deleted User]

liamog wrote: »

We just need to get Mad_Lad into a car with decent heat pump and you'll be singing it's praises on every thread!

If I got into a new EV chances are it will have so much range the last thing I'll be thinking about is a HP.

liamog

Deleted User wrote: »

If I got into a new EV chances are it will have so much range the last thing I'll be thinking about is a HP.

And then they'll be that one time, it's all it will take ...

Kramer

KCross wrote: »

Even on those journeys you may not be inconvenienced as you might have been stopping for a DC charge anyway so an extra few mins isnt going to matter much.

What if having a heat pump saved you 10kWhs, say once a week in winter, on a long trip down the country & back. You need Ionity DC charging because, you're on a long trip, in your long range EV.
26 weeks x 10kWh x €0.79/kWh.

That's €205, or your initial €1000 for the heat pump saved in 5 years.

So, if the heat pump saved just 5kWh per week, which really is nothing, we can all agree, it would pay for itself & save penguins to boot .

Better to have had a heat pump, than never to have heat pumped, at all.

Q.E.D.

Kramer

liamog wrote: »

And then they'll be that one time, it's all it will take ...

This one time, in Band Camp, Mad_Lad's battery was cold......

KCross

Kramer wrote: »

What if having a heat pump saved you 10kWhs, say once a week in winter, on a long trip down the country & back. You need Ionity DC charging because, you're on a long trip, in your long range EV.
26 weeks x 10kWh x €0.79/kWh.

That's €205, or your initial €1000 for the heat pump saved in 5 years.

So, if the heat pump saved just 5kWh per week, which really is nothing, we can all agree, it would pay for itself & save penguins to boot .

Better to have had a heat pump, than never to have heat pumped, at all.

Q.E.D.

There are use cases where it might make sense. Your scenario is very much an edge case in Ireland though and you are assuming that every weekend is so cold that you are needing 10kWh extra for heating... thats a rather big assumption.

How many people are going to fit your scenario in this country?

And in the case of alot of VAG customers they get 1yr free Ionity charging or cheaper rate so the math wont quite add up to what you got above!


Dont get me wrong, I'm all for HP's.... I own two! But its a dubious purchase in this country when it costs €1k+ extra.

Kramer wrote: »

This one time, in Band Camp, Mad_Lad's battery was cold......

That film popped into my head too. I was going to reply something similar but I couldnt find my flute!

Markcheese

Isn't an air to air heat pump just the air-con unit ?
Does it just scavenge heat from a liquid cooling system ? Does the motor even need a cooling system?

[Deleted User]

liamog wrote: »

And then they'll be that one time, it's all it will take ...

Honestly, a HP would make such little difference to me I wouldn't care one way or another if I had 300+ Km range.

I'd probably be going on about the great stereo I got instead lol

[Deleted User]

Kramer wrote: »

This one time, in Band Camp, Mad_Lad's battery was cold......

A cold battery only bothers me if I need to fast charge and I haven't had it pre-heat and then driven it, but oh wait, I got the Rex to go on about now which eliminates cold battery charging and queues lol

[Deleted User]

Kramer wrote: »

What if having a heat pump saved you 10kWhs, say once a week in winter, on a long trip down the country & back. You need Ionity DC charging because, you're on a long trip, in your long range EV.
26 weeks x 10kWh x €0.79/kWh.

That's €205, or your initial €1000 for the heat pump saved in 5 years.

So, if the heat pump saved just 5kWh per week, which really is nothing, we can all agree, it would pay for itself & save penguins to boot .

Better to have had a heat pump, than never to have heat pumped, at all.

Q.E.D.

You're making some assumption there

+ you're forgetting that the HP uses energy too.

You are forgetting any pre-heating is done using the electric heating which lessens the benefit of HP, HP only works while the HV system is energised.

+ the greatest winter consumption in Ireland comes from Wind and wet roads, no HP will do anything to change that, oh and more dense air the colder it gets.

liamog

Deleted User wrote: »

You're making some assumption there

+ you're forgetting that the HP uses energy too.

You are forgetting any pre-heating is done using the electric heating which lessens the benefit of HP, HP only works while the HV system is energised.

+ the greatest winter consumption in Ireland comes from Wind and wet roads, no HP will do anything to change that, oh and more dense air the colder it gets.

You are making a lot of assumptions too, our climate is well suited for the ideal operating range for an onboard heat pump. I find that the percentage drop with heating on is much higher in my car without a heat pump compared to the one with one. That's the percentage drop compared to wearing a woolly hat and running no heat whatsoever.

[Deleted User]

liamog wrote: »

You are making a lot of assumptions too, our climate is well suited for the ideal operating range for an onboard heat pump. I find that the percentage drop with heating on is much higher in my car without a heat pump compared to the one with one. That's the percentage drop compared to wearing a woolly hat and running no heat whatsoever.

I certainly don't need to wear a woolly hat in the i3 but I can understand the benefit of a HP in a lower range ev I just wouldn't bother spending the money on something that would benefit me very little in an EV with 300 km + , as I said a better stereo or better driver automation would be more beneficial to me to spend that money on.

krissovo

My wife sets the inside temperature of the car at 23 degrees, a heat pump is very valuable to us. Its needed 10 months of the year.

Busman Paddy Lasty

krissovo wrote: »

My wife sets the inside temperature of the car at 23 degrees, a heat pump is very valuable to us. Its needed 10 months of the year.

What type of car is it if you don't mind the question?
I did a 23 degrees mild weather test this morning with PTC and it was 10% of total energy used.

[Deleted User]

I drove up with AC on what ye on about ? too humid to have heat set to 23 deg. lol

Busman Paddy Lasty

[Deleted User] wrote: »

I drove up with AC on what ye on about ? too humid to have heat set to 23 deg. lol

Burnt the face off me but I wanted to test it out of curiosity!