Heating Rav4 Prime in cold <-10C weather

borealcat · Dec 14, 2021

I have not had luck finding a post specifically about Prime cold weather interior heating, so starting a thread here.

Due to predominance of temperatures below -10C in our winter, the heat pump is ineffective for heating Prime interior. I am not happy with the degree of heating from the Internal Combustion Engine in cold weather (< -10C), very subtle warmth (correction: I took it out of eco fan mode yesterday at -20C and was very comfortable). And it is not possible to remotely preheat the vehicle in very cold weather (when it would be most useful), since that does not start the ICE. If the ICE turns on to run fans/defoggers and heating when driving in cold weather, it keeps battery fully charged, in other words not neccessarily using the renewable electrical electrical energy the battery was charged with at home.

In my opinion, a traditional radiant heat source would have been a good option for cold temperatures where the heat pump is not working. This drains the battery quicker, but for the user to determine whether that reduction in EV range is worth it for passenger comfort and needed range.

I am looking into a vehicle space heater to put inside cab, connected to 120 VAC with a timer when parked at home. Also looking into a 12V 10 amp space heater powered by vehicle 12V 10A power supply, to use while driving. My concern is that the Prime interior 12V powers supply is only 10A, which may blow with a 10A heater.

Other than that, I am finding the Prime a great vehicle, and the heated steering wheel and seats work very well (we do not have vented seats, just the regular leather of XSE. Apparently the vented seats do not conduct the heat as well).

I will report how things work out regarding 12V running and 120V parked space heaters. I imagine many others in cold climes experience same issues, and I am interested to hear anyone else's solutions.

zumatech · Dec 15, 2021

If you shut off the car with the defrost on won't it start up with the ICE on?

FKHeath · Dec 15, 2021

borealcat said:
I have not had luck finding a post specifically about Prime cold weather interior heating, so starting a thread here.

Since you live in Canada, there is the Toyota Comfort+ system available for the RAV4: Toyota COMFORT+ - Taylor Toyota
It has three optional parts: battery charger, engine block heater, and cabin heater. I don't know if it will work for the Prime, so see your dealer for details.

FKHeath · Dec 15, 2021

Comfort+ Heating Accessories

https://www.toyota.ca/toyota/en/connect/4354/toyota-heating-accessories Block heater - Cabin warmer - Trickle charger -> all connected to block heater plug. I think this is amazing thing for the people that live in areas where temperature drops under -20C/-4F. I was checking with my local...

www.rav4world.com

dbkelly · Dec 15, 2021

borealcat said:
I have not had luck finding a post specifically about Prime cold weather interior heating, so starting a thread here.

Due to predominance of temperatures below -10C in our winter, the heat pump is ineffective for heating Prime interior. I am not happy with the degree of heating from the Internal Combustion Engine in cold weather (< -10C), very subtle warmth. And it is not possible to remotely preheat the vehicle in very cold weather (when it would be most useful), since that does not start the ICE. If the ICE turns on to run fans/defoggers and heating when driving in cold weather, it keeps battery fully charged, in other words not neccessarily using the renewable electrical electrical energy the battery was charged with at home.

In my opinion, a traditional radiant heat source would have been a good option for cold temperatures where the heat pump is not working. This drains the battery quicker, but for the user to determine whether that reduction in EV range is worth it for passenger comfort and needed range.

I am looking into a vehicle space heater to put inside cab, connected to 120 VAC with a timer when parked at home. Also looking into a 12V 10 amp space heater powered by vehicle 12V 10A power supply, to use while driving. My concern is that the Prime interior 12V powers supply is only 10A, which may blow with a 10A heater.

Other than that, I am finding the Prime a great vehicle, and the heated steering wheel and seats work very well (we do not have vented seats, just the regular leather of XSE. Apparently the vented seats do not conduct the heat as well).

I will report how things work out regarding 12V running and 120V parked space heaters. I imagine many others in cold climes experience same issues, and I am interested to hear anyone else's solutions.

I don't know about your Prime, but my 21 Hybrid has pizoelectric heating elements that kick in to provide heat before the engine warms up.

You are CRAZY to even consider on a whim to plug in an electric heater in a car much much less a electric vehicle, CRAZY CRAZY do you realize how much power that would consume and destroy your mileage and cause the ICE to run continuously. You need a big diesel engine for what you want.

NameofUser · Dec 15, 2021

borealcat said:
I have not had luck finding a post specifically about Prime cold weather interior heating, so starting a thread here.

Due to predominance of temperatures below -10C in our winter, the heat pump is ineffective for heating Prime interior. I am not happy with the degree of heating from the Internal Combustion Engine in cold weather (< -10C), very subtle warmth. And it is not possible to remotely preheat the vehicle in very cold weather (when it would be most useful), since that does not start the ICE.

You inquire about a Prime, but post in the Hybrid section (2019+ model year). What vehicle are you truly talking about? If you indeed have a Prime, click on any posting w/in your thread, and "REPORT" to request your post be moved to the RAV4 Prime.

If you picked up a NEW car, did anyone NOT tell you about the COMFORT+ accessory?
Did you NOT browse the accessories: online or at the dealership?

Toyota Genuine Accessories | Toyota Canada

Find the latest Toyota accessories and TRD parts for your car, truck or SUV online right here. Learn more about genuine auto Accessories from Toyota Canada.

www.toyota.ca

If you truly have a R4P (RAV4 Prime), you failed to research your vehicle purchase.
Vehicles that use a Heat Pump for the HVAC system do NOT perform well in VERY COLD environments!
You are finding this out after the fact. Poor heat performance from vehicles with Heat Pump HVAC systems is the downside of Heat Pumps, but they are very efficient and help increase EV range for EV/PHEV vehicles. But, Heat Pumps are not able to really heat up the car in VERY cold environments. A vehicle heat pump HVAC needs a supplement heat source like a tradition coolant based heater core, for the VERY cold environment. This would be impossible for an EV, but possible for a PHEV. However, gas mileage would decrease a lot if the heater relied on HOT engine coolant. Obviously manufactures sacrified warmth for greater EV range by going w/ a Heat Pump.

If you really want hot heat, you'll have to change vehicles to one w/ a coolant based heater core, or move w/ your R4P to an area that is less cold, so the Heat Pump can actually provide you some heat.

ColoradoPrimeTime · Dec 15, 2021

NameofUser said:
If you truly have a R4P (RAV4 Prime), you failed to research your vehicle purchase.
Vehicles that use a Heat Pump for the HVAC system do NOT perform well in VERY COLD environments!
You are finding this out after the fact. Poor heat performance from vehicles with Heat Pump HVAC systems is the downside of Heat Pumps, but they are very efficient and help increase EV range for EV/PHEV vehicles. But, Heat Pumps are not able to really heat up the car in VERY cold environments. A vehicle heat pump HVAC needs a supplement heat source like a tradition coolant based heater core, for the VERY cold environment. This would be impossible for an EV, but possible for a PHEV. However, gas mileage would decrease a lot if the heater relied on HOT engine coolant. Obviously manufactures sacrified warmth for greater EV range by going w/ a Heat Pump.

If you really want hot heat, you'll have to change vehicles to one w/ a coolant based heater core, or move w/ your R4P to an area that is less cold, so the Heat Pump can actually provide you some heat.

I was with you for the first half but you lost me at the end. The RAV4 PRIME (not hybrid) has a heat pump (for heating and cooling) as well as a traditional heater core (for using hot engine coolant to heat the cabin). It’s actually quite a brilliant (and complicated) system that is able to cool the battery, heat/cool the cabin, heat/cool the engine, AND/OR provide dehumidification as needed.

OP is simply saying that when the engine and heater core are on in the Prime, it still does not provide enough heat, which is where that comfort accessory pack for very low temperatures comes into play.

This seems it would be true whether he had a Prime, hybrid, or conventional ICE car, since no matter what, an engine alone appears to be not enough to heat the cabin when it’s THAT cold out.

That still seems weird to me though. I would think that even in 0F temps, if you give the ICE plenty of time to fully warm up, it should be able to provide plenty of comfort heating to the cabin. But I guess not? OP, you are setting the temp as high as possible and turning off “Eco heat/cool”, right? You can also try forcing recirculation mode on (which is off by default in heating mode), at least until the cabin is pre heated.

But yeah, overall, if you live in a super super cold area, you’ll quickly see how the benefits of an EV or PHEV are lessened given the cabin heating problem, as well as the cold weather battery range problem.

TomKatt · Dec 15, 2021

I'll tell you this much - IMO my regular ICE '18 LE does not generate nearly the amount of heat my older cars did (even with smaller engines)... A "side effect" of increased fuel efficiency is that less heat is generated as waste, which is what is used to heat the cabin. Were it not for the added PTC electric heating element, even the ICE cars would be chilly (and they still are a bit).

NoelinColorado · Dec 15, 2021

I recommend a middle to heavier weight down jacket--you'll need it when you get out of the car anyway. I've driven our R4P at -8C once and was fine with just the heated seat and steering wheel, but I had a middle weight down jacket on and was surprisingly comfortable. One feature I wish R4P offered was simply to operate in full ICE mode only--a simple button press to bypass EV/HV. As a HV, the ICE shuts down too often to maintain full coolant temp as high as possible. I guess you can turn the front defroster and A/C on and perhaps that forces the ICE to stay on? Haven't tried it yet because I only am in HV mode once every two weeks or so to exercise the ICE, and to use fuel up before it goes stale.

ColoradoPrimeTime · Dec 15, 2021

You could always operate in Charge mode if all else fails, to force the engine to stay on (and run at higher revs than normal). This should create plenty of heat!

Agreed though on the jacket.
If it’s below freezing aren’t you wearing a jacket anyway? Why do you need the cabin at 80F? Haha.

NoelinColorado · Dec 15, 2021

ColoradoPrimeTime said:
If it’s below freezing aren’t you wearing a jacket anyway? Why do you need the cabin at 80F? Haha.

It's true! I can see it if you're on a long trip and need to be in the car for hours and it's below freezing, but then again the ICE would stay on in that context. Doesn't warm coolant also contribute to incoming HVAC air, or is it either/or heat pump, or hot coolant?

TomKatt · Dec 15, 2021

Maybe it's me, but below zero is cold, jacket or no jacket. Cabin heat helps quite a bit. If heat was an option, it would be the only option I'd purchase.

iTim314 · Dec 15, 2021

NoelinColorado said:
It's true! I can see it if you're on a long trip and need to be in the car for hours and it's below freezing, but then again the ICE would stay on in that context. Doesn't warm coolant also contribute to incoming HVAC air, or is it either/or heat pump, or hot coolant?

Correct. The heat pump warms the engine coolant when the engine is off, then a traditional heater block extracts heat from the coolant to warm the cabin. It is complicated, but if you have looked under the hood of the RAV4 Prime, you'll realize most of what you see is refrigerant lines. It is a complicated system.

The coldest it has been here so far this season is 27ºF. The cabin had no issues heating, and when the engine was running, the air blowing out was damn near hot.

borealcat · Dec 15, 2021

FKHeath said:
Since you live in Canada, there is the Toyota Comfort+ system available for the RAV4: Toyota COMFORT+ - Taylor Toyota
It has three optional parts: battery charger, engine block heater, and cabin heater. I don't know if it will work for the Prime, so see your dealer for details.

Thanks! We were offered the block heater for the Prime and had that installed at time of purchase. The dealer is getting back to me about the Comfort+ system.

borealcat · Dec 15, 2021

dbkelly said:
I don't know about your Prime, but my 21 Hybrid has pizoelectric heating elements that kick in to provide heat before the engine warms up.

You are CRAZY to even consider on a whim to plug in an electric heater in a car much much less a electric vehicle, CRAZY CRAZY do you realize how much power that would consume and destroy your mileage and cause the ICE to run continuously. You need a big diesel engine for what you want.

😊 Very small heater to take bite off cold and keep windshield clear, without activating fan which starts engine. If trip range is small, the effect of a small heater on range could be nominal, and would only use electricity which was used to charge the vehicle, which is renewable. Simply aspiring to avoid engaging the ICE. But I apologise for any confusion, I accidentally posted in the Hybrid Forum, when this is for a plug-in hybrid Prime.

NoelinColorado · Dec 15, 2021

TomKatt said:
Maybe it's me, but below zero is cold, jacket or no jacket.

It's not just you, but operative were...medium weight down, not just 'a jacket or no jacket. And combined w/ steering wheel and seat warmers can go a long ways to keep you comfortable enough, though certainly warmer cabin is preferred. And if all heating options fail, I can always don this guy I bought when I moved to Colorado from sunny California, good to at least -30C! If it's really cold I will take this in the car, without wearing it, in case the car ever breaks down:

borealcat · Dec 15, 2021

NameofUser said:
You inquire about a Prime, but post in the Hybrid section (2019+ model year). What vehicle are you truly talking about? If you indeed have a Prime, click on any posting w/in your thread, and "REPORT" to request your post be moved to the RAV4 Prime.
View attachment 174997

If you picked up a NEW car, did anyone NOT tell you about the COMFORT+ accessory?
Did you NOT browse the accessories: online or at the dealership?

Toyota Genuine Accessories | Toyota Canada

Find the latest Toyota accessories and TRD parts for your car, truck or SUV online right here. Learn more about genuine auto Accessories from Toyota Canada.

www.toyota.ca

View attachment 174996

If you truly have a R4P (RAV4 Prime), you failed to research your vehicle purchase.
Vehicles that use a Heat Pump for the HVAC system do NOT perform well in VERY COLD environments!
You are finding this out after the fact. Poor heat performance from vehicles with Heat Pump HVAC systems is the downside of Heat Pumps, but they are very efficient and help increase EV range for EV/PHEV vehicles. But, Heat Pumps are not able to really heat up the car in VERY cold environments. A vehicle heat pump HVAC needs a supplement heat source like a tradition coolant based heater core, for the VERY cold environment. This would be impossible for an EV, but possible for a PHEV. However, gas mileage would decrease a lot if the heater relied on HOT engine coolant. Obviously manufactures sacrified warmth for greater EV range by going w/ a Heat Pump.

If you really want hot heat, you'll have to change vehicles to one w/ a coolant based heater core, or move w/ your R4P to an area that is less cold, so the Heat Pump can actually provide you some heat.

Thanks very much for the info. No I am not finding this out after the fact, I was aware heat pump does not work below -10, and was aware the ICE kicks in to supply heat. Since the electricity we charge the vehicle with is predominantly renewable, I am interested to run in EV mode when below -10, and find a solution that can use the electricity the vehicle was charged with to heat cab and clear windshield without starting ICE. Hybrid with ICE can always be used when battery is low, but it seems a shame to run the engine from the start of trip just to heat the cab.

TomKatt · Dec 15, 2021

That add-on heater sounds like the thing for you... Pretty much just a 1200W 120V barn heater that gets permanently installed into your car, along with a fancy remote starter. If your electricity is from a renewable source, go ahead and burn the KW's

borealcat · Dec 15, 2021

ColoradoPrimeTime said:
I was with you for the first half but you lost me at the end. The RAV4 PRIME (not hybrid) has a heat pump (for heating and cooling) as well as a traditional heater core (for using hot engine coolant to heat the cabin). It’s actually quite a brilliant (and complicated) system that is able to cool the battery, heat/cool the cabin, heat/cool the engine, AND/OR provide dehumidification as needed.

OP is simply saying that when the engine and heater core are on in the Prime, it still does not provide enough heat, which is where that comfort accessory pack for very low temperatures comes into play.

This seems it would be true whether he had a Prime, hybrid, or conventional ICE car, since no matter what, an engine alone appears to be not enough to heat the cabin when it’s THAT cold out.

That still seems weird to me though. I would think that even in 0F temps, if you give the ICE plenty of time to fully warm up, it should be able to provide plenty of comfort heating to the cabin. But I guess not? OP, you are setting the temp as high as possible and turning off “Eco heat/cool”, right? You can also try forcing recirculation mode on (which is off by default in heating mode), at least until the cabin is pre heated.

But yeah, overall, if you live in a super super cold area, you’ll quickly see how the benefits of an EV or PHEV are lessened given the cabin heating problem, as well as the cold weather battery range problem.

Yes indeed when I turned off eco fan mode (tested yestarday at -20C), plenty toasty 😊 . And I finished trip with eco fan mode on and stayed warm, so that is all good. Still interested in avoiding ICE altogether, to use the renewable energy the vehicle was charged with, hence a very small heater to take bite off cold and clear windshield might do it, with manageable impact on range. Will see... otherwise just going hybrid with ICE will be the solution at colder temps.

borealcat · Dec 15, 2021

NoelinColorado said:
It's not just you, but operative were...medium weight down, not just 'a jacket or no jacket. And combined w/ steering wheel and seat warmers can go a long ways to keep you comfortable enough, though certainly warmer cabin is preferred. And if all heating options fail, I can always don this guy I bought when I moved to Colorado from sunny California, good to at least -30C! If it's really cold I will take this in the car, without wearing it, in case the car ever breaks down:
View attachment 175012

Thats it!

We actually also used a blanket over legs, which with hot seat and steering wheel, very comfortable. That is when running exclusively EV below -10C. But the window fogs up, so need to turn on fan... which engages ICE... trying to find the solution where we can use battery (charged predominantly with renewable energy) primarily.

Heating Rav4 Prime in cold <-10C weather

borealcat

zumatech

FKHeath

FKHeath

Comfort+ Heating Accessories

dbkelly

NameofUser

Toyota Genuine Accessories | Toyota Canada

ColoradoPrimeTime

TomKatt

NoelinColorado

ColoradoPrimeTime

NoelinColorado

TomKatt

iTim314

borealcat

borealcat

NoelinColorado

borealcat

Toyota Genuine Accessories | Toyota Canada

TomKatt

borealcat

borealcat

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