Does the cabin warm more slowly while battery & motors are still heating up?

[MrMusAddict]

I've been pleasantly surprised at how quickly the cabin cools and warms. However last night I decided to take it on a 30 min drive to the next town over, and it felt like it was constantly pushing through cool/room-temp air the entire way despite having it set to 75℉. I finally set it to 80℉, at which point it felt like 72℉.

It was a cold start. The battery & motors were around 40℉ when I left my home. By the end of the drive my front motor (DM) got to around 105℉, and my battery was around 75℉. It was only at this point that 80℉ felt like 80℉.

On the drive back home, the motor was still reporting around 100℉ when we left, and the battery was around 60℉. Under these conditions, 72℉ felt like 72℉ and was pleasant.


Update 1/8/2024: I just got the truck back from a service appointment for other things, and I asked them to look at this too. Here's their official note on the issue:


Concern: Customer states that temp has to be increased to over 80degrees to get the cabin comfortable at 70 degrees.

Cause: Software bug causing the Evaporator to freeze over and disturb airflow to PTC heater

Correction/Remedy: Climate Control General Diagnostic | Labor Code: 266499012


I should note that the tech said this wasn't something they could fix themselves; they have to wait for a firmware update or something along those lines. Not sure if that would be wrapped up in an OTA.

On my 4 hour drive back home in 35° rain, the cabin remained in the low 60's despite having the temp set to HI (I think 85°)? Thankfully I brought my jacket and gloves.

It wasn't until I charged at a fast charger that the motors and battery actually warmed up, which I'm assuming thawed the evaporator. Finally at that point, for the last hour of my drive, I was able to get the cabin up into the 70's.

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[R1Thor]

I don't know that I could draw any correlations, but I've definitely 'felt like' it's been inconsistent lately. I do tend to pre-heat the cabin before I leave when it's cold and I have the foresight to get ready. I do find that seems to *help* maintain consistency.

But it could very well simply be the system playing 'catch up' while you're in motion, especially on particularly cold days until everything reaches homeostasis. In other words, until things come up to temperature, and all internal thermistors agree and the system then starts to output correspondingly. I'm not an HVAC expert however, especially vehicle-based. And all of my experience prior to this is with an ICE vehicle which requires the engine to be up to temperature before getting heat. I will say, that this truck DEFINITELY gets warmer faster than any previous car I've owned.

 

[HaveBlue]

The seat warmers are the quickest most efficient way to get heat and the rivian ones are good. Tesla figured that one early on. The rivian uses waste heat from the inverters to warm the cabin and battery for the space heating portion.

 

[MrMusAddict]

Update: I just got the truck back from a service appointment for other things, and I asked them to look at this too. Here's their official note on the issue:


Concern: Customer states that temp has to be increased to over 80degrees to get the cabin comfortable at 70 degrees.

Cause: Software bug causing the Evaporator to freeze over and disturb airflow to PTC heater

Correction/Remedy: Climate Control General Diagnostic | Labor Code: 266499012


I should note that the tech said this wasn't something they could fix themselves; they have to wait for a firmware update or something along those lines. Not sure if that would be wrapped up in an OTA.

On my 4 hour drive back home in 35° rain, the cabin remained in the low 60's despite having the temp set to HI (I think 85°)? Thankfully I brought my jacket and gloves.

It wasn't until I charged at a fast charger that the motors and battery actually warmed up, which I'm assuming thawed the evaporator. Finally at that point, for the last hour of my drive, I was able to get the cabin up into the 70's.

 

[DTown3011]

I find that Auto mode with recirc is the best setting for keeping the cabin warm on cold days. YMMV

 

[MrMusAddict]

I find that Auto mode with recirc is the best setting for keeping the cabin warm on cold days. YMMV

YMMV indeed. That's how it was my whole drive back from my service appt, and there wasn't any improvement. It was just blasting cold air until I got to a fast charger. The truck even preconditioned for 30 min before the charge, and that didn't help at all.

 

[DTown3011]

YMMV indeed. That's how it was my whole drive back from my service appt, and there wasn't any improvement. It was just blasting cold air until I got to a fast charger. The truck even preconditioned for 30 min before the charge, and that didn't help at all.

Bummer about the software bug you reported above, so hopefully there are some changes coming. I didn't love the HVAC when I first got my truck but now it's certainly better than it was. But finnicky for sure! The magic number is absolutely 72, anything lower it seems to blow cold and higher seems to switch to heat.

 

[Frisbee]

I generally run the heat on manual and recirculation to keep the AC from turning on to remove moisture it erroneously detects.

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