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Comment by Thlom | Hacker News Reader

Why? A lot of EVs these days comes with a heatpump so heating doesn’t use that much power. I live in a cold country where 98% of new cars are EVs and I have never heard anyone asking for something like this. A quick search on popular EV forums shows a few threads from 2010-2014. That’s it. I know webasto has a product like this, but there’s practically zero cars on the road with it installed.

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Heat pumps are mostly useless when it is minus -20 C. Diesel heater is the most practical solution. Sodium or LMFP batteries will help, but even with them the range reduction in winter due to the need for heating and increased drag from cold air is just too great.

diesel fuel itself needs to be heated at -20 C and below. I used to have a diesel car which would start itself up periodically when its fuel temp was getting close to -20 C, just to warm up the tank & pipes.

Yeah, the 1999 diesel truck I had did the entirely opposite thing: it had a 120v electric block heater, so you'd plug it in when it was cold. (In New England, I used it once to see how it worked, but never actually needed it in practice.) At the time I saw stories (I never confirmed in any depth though) that Minnesota had 120v outlets on parking meters, giving some sort of weather-encouraged compliance :-)

> Heat pumps are mostly useless when it is minus -20 C.

Two-thirds of households in Norway are heated by heat-pump, so I don't think that can be true.

How many homes have heat pump as their sole heating?

That's a useless statistic without knowing if it's their sole heat source. Just based on costs, I'm betting there's a lot of wood stoves and pellet stoves kicking around.

you're not making the point you think you are. The average January temperature in most of Norway is about 10 C higher than in most of Yukon and Alaska. Norway just isn't that cold.

That said, heat pumps absolutely do work in -20 C. I would know because i have two at home and one in the car. All three worked just fine at -25 C this past winter.

I meant in heat pumps in cars due to size constrains. For homes there are heat pumps that work even at minus -30C, but one just cannot fit that into a car.

And I really do not get why there is no even option to have a diesel heaters in cold climates. It adds like 100 kilometres per long trip for a litre of fuel when it is cold and allows to use smaller and cheaper battery in EV.

Ok i get that some people really do need to deal with extreme temperatures regularly, but it totally misses the point when discussing a mass market car like the Corolla. It’s like asking business casual footware to be equipped with crampons for when you need to walk up a glacier.

The point of diesel heater is to remove the need to plugin hybrid in many cases and just go with EV plus heater.

if you get into standstill traffic in the winter, it's actually life-threatening not to have alternative power source that can warm up the passengers (and the battery). One interstate road I'm driving sometimes, has many abandoned Teslas sitting on the side of the road after a sleepless night of staying in traffic during some snow blizzard...

No different than gas vehicles running out of fuel.

Do the math and let's say theres even 50 percent charge of a 60kwh pack...and you just blast a 1000w of heat constantly....thats still 30 hours of heating at 1kw of power lol.

Gas vehicles burn .25 to .5 gallons per hour so uh...that 16 gallon tank completely topped off is 'only' 32hours. Half the tank and down to 16hours.

Webasto would like to have a word. "..can operate for up to 22 hours on less than one gallon of fuel.."

https://www.webasto.com/en-us/choose-vehicle-solution/oil-an...

Those are aftermarket products for use in heavy vehicles, not something that's present (or usable) in passenger cars.

It's quite normal in colder climates, but mostly in Diesel cars. I had it in my VW Multivan. I've never heard of anyone installing Webasto in their EV.

There are all sorts of China knockoffs of them going up and down the size scale.

They are pretty common in passenger cars too, google 'standheizung' or 'stationary heater' and you'll find a ton of them. You might not realize that that is what it is. On cars sold in the Nordics and some German brands it is just a checkbox during the order process.

Just as a point of contention. Its hard to find an EV that is only gonna pull 1000w using the heater.

My EV doesn't have a heatpump and the resistive heating pulls up to 8KW warming up the cabin on a cold day.

I keep a 12v heated blanket around to save power. (no heated seats/steering wheel)

Heated seats are where the real power savings come in.

It's amazing how comparing 1kw of power to vastly more than 1kw of power results in skewed results!

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