What is your protocol for testing A/C vent temperature?

[John105]

30 degrees below ambient temperature would be absolutely miserable.

Call me weird but I don't add heat to AC when driving. Seems a bit counterintuitive and wasteful. Would one do that with a central AC (which has a 20-22F drop)? So as such, both our passenger cars are uncomfortable, "eventually," when running the AC and vents blowing right on a person (like you say 40F would be). But not my wife's SUV. I'm not a genius, close, but not technically, so I don't know how a system really works that has front and rear evaps, and only one compressor. So I'm not sure something is wrong, but I went as far as hooking up gauges and getting 4 oz. of refrigerant in.

Just an observation, most cars are in fact uncomfortable to have the AC blowing directly on occupants. At 95F and a 72F dewpoint, not sure. But at something more reasonable like 80F and humid.

There are times that this forum is chasing problems that do not exist, it would seem. Which is fine, as I tend to be theoretical too and want to know how things work. Not everyone does.

 

[Nick1994]

Call me weird but I don't add heat to AC when driving. Seems a bit counterintuitive and wasteful. Would one do that with a central AC (which has a 20-22F drop)? So as such, both our passenger cars are uncomfortable, "eventually," when running the AC and vents blowing right on a person (like you say 40F would be). But not my wife's SUV. I'm not a genius, close, but not technically, so I don't know how a system really works that has front and rear evaps, and only one compressor. So I'm not sure something is wrong, but I went as far as hooking up gauges and getting 4 oz. of refrigerant in.

Just an observation, most cars are in fact uncomfortable to have the AC blowing directly on occupants. At 95F and a 72F dewpoint, not sure. But at something more reasonable like 80F and humid.

There are times that this forum is chasing problems that do not exist, it would seem. Which is fine, as I tend to be theoretical too and want to know how things work. Not everyone does.

I’m not sure what you’re getting at, but 30 degrees below ambient temperature would mean 85 degree air coming out of my vents.

In reality it’s closer to 40 degrees out the vents, so a 75 degree difference.

 

[John105]

I’m not sure what you’re getting at, but 30 degrees below ambient temperature would mean 85 degree air coming out of my vents.

In reality it’s closer to 40 degrees out the vents, so a 75 degree difference.

Never mind

 

[Jeep_Riot]

I've always found that my A/C was coldest (according to a thermometer placed in the vent) on lower fan settings. This has been true in every car I've checked. I'm not talking a lot but say 42*F on low vs. 44 or 45*F on high.
I never measured it against the outside temperature but 45* F or lower at the vent is my goal.

Might have something to do with dwell time.

 

[2strokeNorthstar]

30 degrees below ambient temperature would be absolutely miserable.

I agree, on my way home yesterday the outside temp was 118. 88 degree vents would be a sauna.