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Renault Zoe Intens Q210 22kw 2013
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Discussion Starter · #1 ·
Today I turned off PTC cabin heating on my Zoe (ZE20) - I can easily enable it again. I see it was drawing 1800w (1.8kw) electrical power when it calls for it through the HVA settings and to be honest I would rather have the range in the winter.

has anyone else done this? - I wonder what implications. I am figuring the electric PTC heater 'helps' the Heatpump system in extremely cold weather and helps heat up the cabin/interior quicker than just heatpump system alone? - most probably the daftest time of the year to disable it seeing as it middle of winter and low temps around 0c but i just thought I would try it with heatpump system alone and see how much difference it will make to range.
 

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Zoe Devotee
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The heatpump needs something with heat to build from, it can't pull in minus 2 air and warm it, there needs to be some warmth to start with. If you don't want heat isn't it easier to just not have the heating on than disable the ptc with DDT4All and potentially breaking other stuff you can't re-enable.
 

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Renault Zoe Intens Q210 22kw 2013
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Discussion Starter · #3 ·
The heatpump needs something with heat to build from, it can't pull in minus 2 air and warm it, there needs to be some warmth to start with. If you don't want heat isn't it easier to just not have the heating on than disable the ptc with DDT4All and potentially breaking other stuff you can't re-enable.
ah right thanks - I might put it back to how it was then. - was going to just try it and see if it would be hot enough without the additional cabin heater, or see if anyone else has got on OK with just the heatpump system running and only the heat pump supplying the heat
 

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Zoe R110
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Couldn't you just run in eco mode? We know it limits the amount of power going to the heating system. I'd kind of assume from the cars point of view turning off the PTC would be an easy win.
Don't know for sure though, and of course it does limit you to 60mph.
 
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2020 BMW i3S 120Ah BEV
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The heatpump needs something with heat to build from, it can't pull in minus 2 air and warm it, there needs to be some warmth to start with. If you don't want heat isn't it easier to just not have the heating on than disable the ptc with DDT4All and potentially breaking other stuff you can't re-enable.
I don't think this is quite the truth, it's more that they reduce in efficiency or at least reduce "energy output to input ratio" and become more or less pointless when the source temperature drops much below about -10 degrees. After all a household fridge freezer can draw heat from a freezer at -18 and pump it into your kitchen at +20 with no issues.

We never see temperatures below 250 Kelvin after all, which is pretty hot by galactic standards.
 

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Co-author of CanZE. Q210 nov 2013
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I don't think this is quite the truth, it's more that they reduce in efficiency or at least reduce "energy output to input ratio" and become more or less pointless when the source temperature drops much below about -10 degrees. After all a household fridge freezer can draw heat from a freezer at -18 and pump it into your kitchen at +20 with no issues.

We never see temperatures below 250 Kelvin after all, which is pretty hot by galactic standards.
Correct. The PTC is therefor not on the input side pf the heatpump. Even 2 kW is nothing to heat the interior of this uninsulated, vented, steel-glass box sitting in windy -5C. It does however rather quickly defrost the 4 Kelvin universe facing front window fairly quickly (yes that is the reason why frustratingly the windshield freezes up much worse than the side windows).
 

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Zoe R110
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We never see temperatures below 250 Kelvin after all, which is pretty hot by galactic standards.
256K in Scotland just yesterday !
 
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Renault Zoe Intens Q210 22kw 2013
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Discussion Starter · #13 ·
here's a point - you know when they say 'dont put a freezer in the outside garage or shed because it will stop working at (whatever degrees is it +2c to -5c is it?) ' - so can the same apply to air conditioning / heat pump ? can that stop working altogether at a certain degree of coldness and thats why the electric PTC heaters have to kick in?
 

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ZE40 R110
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Bjorn has been testing EV's with and without heatpumps at 245K in Norway, they seem to work at various inefficient levels boosted by PTC heating or scavenging heat from the rotors / battery depending on the EV. He's not a big fan of the Zoe unfortunately so no low temperature testing for the Zoe.

However my Zoe defrosted itself at 268K this morning while I ate my Rice Krispies and then felt sorry for my Neighbours who had their Diesel Weasels idling on their drives while they scraped off the ice, although seeing as the Zoe sounds like a Harrier jump jet spooling up when its preheating on the drive, presumably I'm disturbing them more! :).
 

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Zoe R110
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Freezers aren't designed to be run in sub 273k conditions. With the amount of noise coming from the heat pump on the Zoe I'd guess it works at a higher pressure.
Well that or they are powered by a trapped rhino in distress whilst trying to pass a VW campervan....sideways !
 

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Correct. The PTC is therefor not on the input side pf the heatpump. Even 2 kW is nothing to heat the interior of this uninsulated, vented, steel-glass box sitting in windy -5C. It does however rather quickly defrost the 4 Kelvin universe facing front window fairly quickly (yes that is the reason why frustratingly the windshield freezes up much worse than the side windows).
How could you forget greenhouse gases, and cirrus clouds?

The effective sky temperature is variable, but -40 C (233 K) would be a lot closer to the truth than 4 K.
 

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Renault Zoe Intens Q210 22kw 2013
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Discussion Starter · #17 ·
Couldn't you just run in eco mode? We know it limits the amount of power going to the heating system. I'd kind of assume from the cars point of view turning off the PTC would be an easy win.
Don't know for sure though, and of course it does limit you to 60mph.
thats got me thinking now, i wonder when you put the zoe into eco mode apart from limiting the speed of the car and i know it does do something to the heating (because the heating is normally a lot more crappier with eco button turned on) I wonder if indeed it is turning off the PTC heating and thats why the heating is rubbish with eco on or is it limiting the heatpump? - either way it does something to the heating and its not as hot
 

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The heatpump needs something with heat to build from, it can't pull in minus 2 air and warm it, there needs to be some warmth to start with. If you don't want heat isn't it easier to just not have the heating on than disable the ptc with DDT4All and potentially breaking other stuff you can't re-enable.
Regarding heat pumps, think in Kelvin rather than Celsius. There's still plenty of energy in the air when it's -2ºC air outside, because that's 271K. There's nothing magical for heat pumps about 0ºC. There is for humans though. Generally, humans don't like air at 271K being blown in their face.
 

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Regarding heat pumps, think in Kelvin rather than Celsius. There's still plenty of energy in the air when it's -2ºC air outside, because that's 271K. There's nothing magical for heat pumps about 0ºC. There is for humans though. Generally, humans don't like air at 271K being blown in their face.
Except water freezes at or around zero centrigrade and makes the heat transfer zero because the condenser has a coating of ice.
 
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