Is this really an article saying heat pumps are more efficient than resistive heaters? Yes, that is why heat pumps exist.
The biggest issue is the battery itself. If it gets cold enough you can have difficulty even charging an EV outdoors. I would be a lot more concerned with whether or not my battery is well insulated and heated. Heat pumps are great and should be the default, but unless you’re going really far or have a very low range EV it’s not a huge issue.
Yes, resistive heat is expensive, but that’s only part of what makes heat pumps in cars more effective. They don’t just heat your cabin, they heat your battery so you maintain range while it’s cold out. Here’s an article with more details and some pretty infographics.
It defintely is a huge issue, considering resistive heaters use 3x as much energy. Most EVs have a “low range” and anything you can do increase it without adding more batteries and weight and cost, especially in winter, is a huge advantage.
The lowest range EV in the US is 114 miles. The average commute is 52 miles. Most EVs sold in the US have a range of 250 miles or more. So a resistive heater eating 10% of your range is way less of an issue than your battery not charging properly in cold weather. Again, heat pumps should be available, but they aren’t going to save you if cold weather kills your battery.
The average commute is 52 miles. Most EVs sold in the US have a range of 250 miles or more.
No one cares about “average commute” when buying an electric car and considering the offered range. They’re thinking about long trips.
So a resistive heater eating 10% of your range is way less of an issue than your battery not charging properly in cold weather.
Who said anything about batteries “not charging properly”? What does that even mean?
heat pumps should be available, but they aren’t going to save you if cold weather kills your battery.
We’re not talking about killing batteries, we’re talking about electric range. Heat pumps extend your electric range and 20 miles can absolutely be the difference between making it to the next charger or not.
Which have a whole bunch of issues of their own. Like increased mechanical complexity, and that you might use gas so seldom that it becomes significantly water by the time you do need it.
Most people aren’t road tripping in their electric vehicle every day. If you don’t understand how temperature affects battery chemistry, capacity, and charging I don’t understand how you can even be in this conversation.
Most people aren’t road tripping in their electric vehicle every day.
They can’t road trip ever if the vehicle doesn’t have sufficient range. I don’t understand how you can even be in this conversation when you don’t understand basic principles like this.
If you don’t understand how temperature affects battery chemistry, capacity, and charging
I understand how it affects all of these. It doesn’t cause any of it to “not charge properly”. EVs are used in the coldest places in the world with no major problems.
I’ve driven from Madison, WI to Chicago in an EV with ~100 mile range in cold weather. Wouldn’t be my first choice, but I was in a pinch at the time. It can work, but getting a reliable charger network is the biggest problem. Made three stops to chargers that were broken or inaccessible for various reasons.
That was a couple of years back, and I think it’d go a bit smoother now. The Chicagoland area has reasonably good charger network outlays (much better than Minneapolis, which is a joke). Still wouldn’t be my first choice, but it’s workable.
My wife has a Nissan leaf with 60 mile range for commuting, I have an old gas hatchback we can take for road trips. Before going off about how rich and privileged this setup is, the Leaf was purchased for 6k, 4k after tax rebates. Hatchback was purchased for 6k 9 years ago.
I don’t think that’s true? There are cold weather models that can work at COPs > 1.5 at -30C. Are we talking about a sizing constraint for the model here, perhaps?
There are, but then I think you’d have problems with the effective rang of the AC in the summer. To my knowledge this is all about at what temperature the coolant is a liquid and when it’s a gas (because that’s how you exchange heat).
A traditional AC only needs coolant that does this at summer temperatures. A heat pump tries to use one that will work at colder temperatures as well. A cold weather heat pump goes even further but I think there is a sacrifice in AC efficiency in the summer.
Somone please correct me if I’m wrong. But I’m not sure if a do-it-all extreme cold and extreme hot heat pump exists, and as a car manufacturer you want to put in the one that will fit most cases, as opposed to a house which only needs to operate in the range of the climate it is built in.
It would make sense if the two stage heat pumps use different liquids in the different stages. I don’t actually know how these are made, so I can’t assert that this is how it works, but I would be surprised if it worked any other way.
If it is rare enough and you don’t have an emergency that is the right thing. Odds are the rest of your city doesn’t have the ability to deal with those temperatures and so you going out will make things harder for emergency workers who must get out. If your city deals with this often then everyone will know how to deal with it and expect you to deal with it. You cannot shutdown your life for something that happens every single year, but if it is just a day or two every 5 years it isn’t worth being knowing how to deal with it other than the minimum emergency needs (that is make sure your HVAC system at home can handle it)
I mean its more like we can go a winter without below zero F. Its a lot less common in the last decade and usually it does not last to long and that is really for lows. Highes below zero aren’t shockers but yeah we can go some years now without them and for most folks they are doing things while the sun is up. My thing is if I grab a metal doorknob with a bare hand and it is actually painful, then its like ef this im staying inside unless someone forces me out. Even back in the early aughts I had a job that was not wfh all the time like now but did it as needed and I could easily email I was wfh do to the weather being extreme. Its actually the wfh policy outside of all the time type one I like the best. wfh anytime there is a reason to and actually that place was like do not come in if you are sick. if you came in and coughed you would get the maybe you should have stayed home today comment.
I know the resistive heater in my Volt can’t compare to the heat put out by the ICE. Often in the winter we’ll have to run the ICE to keep the cabin warm enough. It does have heated seats and wheel, but my wife is the type to set the heat to max until it gets too hot rather than just picking a temp and hitting auto to let the car manage it.
If the heat pump can put out more heat for less energy, that would be a boon. That might be the second biggest issue (next to range) that has my wife vetoing an all-electric car. She gets the next vehicle, but I want the one after that to be a full EV.
Fwiw, I’ve never had a lack of heat from my cars heat pump. It even warms up faster than a gasoline engine would. Most importantly, I can turn it on remotely to get warm before I get in the car. I never had that with a gas engine
Is this really an article saying heat pumps are more efficient than resistive heaters? Yes, that is why heat pumps exist.
The biggest issue is the battery itself. If it gets cold enough you can have difficulty even charging an EV outdoors. I would be a lot more concerned with whether or not my battery is well insulated and heated. Heat pumps are great and should be the default, but unless you’re going really far or have a very low range EV it’s not a huge issue.
Yes, resistive heat is expensive, but that’s only part of what makes heat pumps in cars more effective. They don’t just heat your cabin, they heat your battery so you maintain range while it’s cold out. Here’s an article with more details and some pretty infographics.
It defintely is a huge issue, considering resistive heaters use 3x as much energy. Most EVs have a “low range” and anything you can do increase it without adding more batteries and weight and cost, especially in winter, is a huge advantage.
The lowest range EV in the US is 114 miles. The average commute is 52 miles. Most EVs sold in the US have a range of 250 miles or more. So a resistive heater eating 10% of your range is way less of an issue than your battery not charging properly in cold weather. Again, heat pumps should be available, but they aren’t going to save you if cold weather kills your battery.
No one cares about “average commute” when buying an electric car and considering the offered range. They’re thinking about long trips.
Who said anything about batteries “not charging properly”? What does that even mean?
We’re not talking about killing batteries, we’re talking about electric range. Heat pumps extend your electric range and 20 miles can absolutely be the difference between making it to the next charger or not.
If only plug-in hybrids existed…
Which have a whole bunch of issues of their own. Like increased mechanical complexity, and that you might use gas so seldom that it becomes significantly water by the time you do need it.
Most people aren’t road tripping in their electric vehicle every day. If you don’t understand how temperature affects battery chemistry, capacity, and charging I don’t understand how you can even be in this conversation.
They can’t road trip ever if the vehicle doesn’t have sufficient range. I don’t understand how you can even be in this conversation when you don’t understand basic principles like this.
I understand how it affects all of these. It doesn’t cause any of it to “not charge properly”. EVs are used in the coldest places in the world with no major problems.
I’ve driven from Madison, WI to Chicago in an EV with ~100 mile range in cold weather. Wouldn’t be my first choice, but I was in a pinch at the time. It can work, but getting a reliable charger network is the biggest problem. Made three stops to chargers that were broken or inaccessible for various reasons.
That was a couple of years back, and I think it’d go a bit smoother now. The Chicagoland area has reasonably good charger network outlays (much better than Minneapolis, which is a joke). Still wouldn’t be my first choice, but it’s workable.
Not sure how you are being downvoted. You’re absolutely right. Everyone I know that wants an EV wants more range.
My wife has a Nissan leaf with 60 mile range for commuting, I have an old gas hatchback we can take for road trips. Before going off about how rich and privileged this setup is, the Leaf was purchased for 6k, 4k after tax rebates. Hatchback was purchased for 6k 9 years ago.
I’m glad that works out for you.
You still need resistive heat as heatpumps don’t work below about -20C and those temperatures happen to at least some car buyers.
I don’t think that’s true? There are cold weather models that can work at COPs > 1.5 at -30C. Are we talking about a sizing constraint for the model here, perhaps?
There are, but then I think you’d have problems with the effective rang of the AC in the summer. To my knowledge this is all about at what temperature the coolant is a liquid and when it’s a gas (because that’s how you exchange heat).
A traditional AC only needs coolant that does this at summer temperatures. A heat pump tries to use one that will work at colder temperatures as well. A cold weather heat pump goes even further but I think there is a sacrifice in AC efficiency in the summer.
Somone please correct me if I’m wrong. But I’m not sure if a do-it-all extreme cold and extreme hot heat pump exists, and as a car manufacturer you want to put in the one that will fit most cases, as opposed to a house which only needs to operate in the range of the climate it is built in.
It would make sense if the two stage heat pumps use different liquids in the different stages. I don’t actually know how these are made, so I can’t assert that this is how it works, but I would be surprised if it worked any other way.
Im in one of those places but where im at its rare and at this point I will resist leaving the house pretty massively at those temps.
If it is rare enough and you don’t have an emergency that is the right thing. Odds are the rest of your city doesn’t have the ability to deal with those temperatures and so you going out will make things harder for emergency workers who must get out. If your city deals with this often then everyone will know how to deal with it and expect you to deal with it. You cannot shutdown your life for something that happens every single year, but if it is just a day or two every 5 years it isn’t worth being knowing how to deal with it other than the minimum emergency needs (that is make sure your HVAC system at home can handle it)
I mean its more like we can go a winter without below zero F. Its a lot less common in the last decade and usually it does not last to long and that is really for lows. Highes below zero aren’t shockers but yeah we can go some years now without them and for most folks they are doing things while the sun is up. My thing is if I grab a metal doorknob with a bare hand and it is actually painful, then its like ef this im staying inside unless someone forces me out. Even back in the early aughts I had a job that was not wfh all the time like now but did it as needed and I could easily email I was wfh do to the weather being extreme. Its actually the wfh policy outside of all the time type one I like the best. wfh anytime there is a reason to and actually that place was like do not come in if you are sick. if you came in and coughed you would get the maybe you should have stayed home today comment.
Yes, they should have both.
I know the resistive heater in my Volt can’t compare to the heat put out by the ICE. Often in the winter we’ll have to run the ICE to keep the cabin warm enough. It does have heated seats and wheel, but my wife is the type to set the heat to max until it gets too hot rather than just picking a temp and hitting auto to let the car manage it.
If the heat pump can put out more heat for less energy, that would be a boon. That might be the second biggest issue (next to range) that has my wife vetoing an all-electric car. She gets the next vehicle, but I want the one after that to be a full EV.
Fwiw, I’ve never had a lack of heat from my cars heat pump. It even warms up faster than a gasoline engine would. Most importantly, I can turn it on remotely to get warm before I get in the car. I never had that with a gas engine
Yeah and a lot are moving to heat pumps if they don’t already use them.
https://www.recurrentauto.com/questions/which-electric-vehicles-have-heat-pumps
There’s a list of models that have them.
If you have two cars, one EV and one ICE is a great option. I do recommend whoever is more enthusiastic about EVs get the first one, though.