asellus

This hasn't happened to me since my horrible mistake of a car 2005 Subaru Legacy GT.

On a drive today, and about an hour in I start noticing I'm getting pretty warm and airflow isn't really.. there anymore. The evaporator froze.

It was sunny, 70F, and around 55% humidity outside. I had the HVAC set to 71, auto, and the seat cooler on the lowest setting. I usually don't leave the seat cooler on for longer than a few minutes, but I forgot about it... if the cooled seats simply use the existing HVAC for drawing cool air instead of a peltier, this could explain it.

Simply turning off the A/C and turning the fan up to max manually for around ten minutes finally brought the vent air down to ambient temperatures. Turned the A/C back on (with seat cooler off) and didn't have an issue for the rest of the drive, about 1.5 hours.

Anyone else ever have this happen on their 991.2? I figured it'd have a defrost cycle.

spdracerut

A dirty evap coil will typically freeze over as the dirt blocks airflow. Lack of airflow, less heat getting to the evap coil and it freezes. Or it could be anything else blocking airflow further upstream. Leaves in the air ducts?

BSO

A frozen evaporator can indicate a low system refrigerant charge. Have seen it happen on a/c systems before.

Jack F

Reasonable guess is low refrigerant. If you thawed things out though and it works I definitely then obviously not. If it happens again, my bet is low refrigerant. Still under warranty!
I needed a recharge on my car twice. Ended up being a bad hose crimp at the compressor I believe.

asellus

Yeah, the only new variable here from normal driving is I had the seat cooler on low the whole time. I'll have to look into exactly what kind of seat cooler system Porsche uses eventually, but otherwise yeah I'll hook up some gauges to the A/C lines and double check refrigerant -- didn't even occur to me to do that, lol.

Thanks!

Jack F

Were you on max seat cooling when the cold air stopped flowing? Maybe there is some coordinated attempt not to over cool you from 2 sides? The Porsche seat cooling is so much more effective than my Audi B9 Allroad. The 911 seats actually really cool me down. It’s a great setup for those that might want them but have experienced less than impressive cooling in other cars.

asellus

Nope, had it on the lowest setting the whole time.

I find that I stop noticing the cooling seats running after 5-10 minutes anyhow, which is why I only run it for a few minutes when I first get into the car.

arter

The ventilated seats in our cars only has a fan that pulls a vacuum on the seat bottom and back.
There is no connection to the A/C system with them.

DBH

Yes, thank you. I don't have ventilated seats but was always under the impression its operation was only a fan(s) pulling air through the seat.

asellus

Good to know! Some use peltiers, some use the HVAC, and some just move air (ventilated vs cooled).

Chris C.

My 2013 needed an A/C charge last year. Not sure they found a leak.