Aircon effectiveness

[Grosbard]

Here's another thing I noticed, and I'm curious if other have noticed this:

When I turn the car on, but don't start it (i.e. hit the start button twice, but don't have the clutch and brake depressed, so it won't start the car), the Aircon is on, but it doesn't blow very cold. If I sit in the car for a minute in this state, I get a good sense of what the Aircon temp is at in this state. Then, when I start the car (no other variables changed), all of a sudden the air blows much colder. I know various belts are driven off the running engine, but surprised at the magnitude of the cooling difference since I haven't noticed a difference in any previous car I've driven. i.e. on those other cars when the Aircon is on, it gives the same amount of cooling regardless of whether the car is running or not.

Wondering if knowing this info triggers some thoughts from somebody about what's causing the weak Aircon in my car!

[KillerBMotorsport]

Originally Posted by Grosbard

Here's another thing I noticed, and I'm curious if other have noticed this:

When I turn the car on, but don't start it (i.e. hit the start button twice, but don't have the clutch and brake depressed, so it won't start the car), the Aircon is on, but it doesn't blow very cold. If I sit in the car for a minute in this state, I get a good sense of what the Aircon temp is at in this state. Then, when I start the car (no other variables changed), all of a sudden the air blows much colder. I know various belts are driven off the running engine, but surprised at the magnitude of the cooling difference since I haven't noticed a difference in any previous car I've driven. i.e. on those other cars when the Aircon is on, it gives the same amount of cooling regardless of whether the car is running or not.

Wondering if knowing this info triggers some thoughts from somebody about what's causing the weak Aircon in my car!

The BRZ's A/C has a compressor driven by belts. Without the engine running, it does not function (aside from the cabin fan). Some cars use an electric powered compressor and will still function when the engine is not running. The BRZ does not.

[Grosbard]

Originally Posted by KillerBMotorsport

The BRZ's A/C has a compressor driven by belts. Without the engine running, it does not function (aside from the cabin fan). Some cars use an electric powered compressor and will still function when the engine is not running. The BRZ does not.

Ah, I suspected something like this. Thanks for the clarification on this difference.

[sato]

Originally Posted by Ultramaroon

In the right conditions, it would snow in the plane I used to work on in the navy. Was always a hoot.

Some of your Navy's planes are cold AF. There was a time where I would stay near electronic equipment just to stay "somewhat comfortable".

Wish I had "A/C" like that on my car. That, or that my car could fly.

[LRNAD90]

Originally Posted by Grosbard

Ah, I suspected something like this. Thanks for the clarification on this difference.

This is exceedingly rare for a street car that is not an EV or Hybrid. Curious what cars you use to owned that had cold AC with the engine off..

[KillerBMotorsport]

Originally Posted by LRNAD90

This is exceedingly rare for a street car that is not an EV or Hybrid. Curious what cars you use to owned that had cold AC with the engine off..

For me, 2017 911. I think it's more common on many cars with auto-stop.

[Grosbard]

I think I experienced this on a Lexus LS430 recently, but maybe I'm misremembering.

[Lelandjt]

Originally Posted by KillerBMotorsport

For me, 2017 911. I think it's more common on many cars with auto-stop.

It must only be capable of running for a minute tops or killing the battery would be a real possibility.

[KillerBMotorsport]

Originally Posted by Lelandjt

It must only be capable of running for a minute tops or killing the battery would be a real possibility.

I never timed it, but it did vary based on demand and temps. Sometimes it would not cycle back on for quite a while. It seemed to work well. If I were to guess, I'd say on average the engine would be off for 3 minutes and on for 1 (or less) during parked A/C operation.

[X25]

Now that I've picked up and been driving my '23, I've also noticed that the AC is very weak at idle. This pretty much means that you'll be disappointed during stop and go traffic, as I'm guessing the variable compressor runs at very low pressure. Anyway, as soon as you're cruising, it wakes up and cools down nicely... Problems with having a tiny engine I guess : ) Instead of bumping idle RPM like most cars, it bumps down the compressor. Perhaps it was made to gain another MPG in EPA loop that requires AC on, who knows...