Auto AC is weak when it is hot outside

[Glen Baker LLC]

You will never see 40 degree air. A mechanic/ac expert told me once the best you can hope for is 15 degrees below ambient air. So 80 outside, 65 coldest at vents. I don't know if he was correct. Please remember the temp setting is NOT the temp the vent air will be. It is just like a house thermostat. It will heat or cool to that temperature if it can.

I don't think, if I were you, I would return to that mechanic/ac expert.
Looking at it logically and realistically the expert doesn't make sense.
The picture below shows 117° outside. If what the expert told you was true. The interior air would only be blowing between 95 and 100°.
I can assure you that didn't happen. I was very comfortable at 72°

Even my thermometer shows the proper range for AC air.

Most powerful Air Conditioner Ever.

Measured it at 4500 watts in the Hybrid.
That's 6 Horsepower for you EB folks assuming it's of similar capability.

A wall unit for a house is 1800 watts.

The air vents will blow your hair back like a supermodel commercial. No joke.

In central CA I never use higher than fan speed 3.

Sponsored

 

[MavStangVa]

I don't think if I were you, I would return to that mechanic/ac expert.
He doesn't make sense. The picture below shows 117° outside. If what the expert told you was true. The interior air would only be blowing between 95 and 100°.
I can assure you that didn't happen. I was very comfortable at 72°

Even my thermometer shows the proper range for AC air.

I did say I didn't know if he was correct. Was your AC on recirculate or outside? I find recirc will get very cold if I leave it on manual.

 

[Glen Baker LLC]

I did say I didn't know if he was correct. Was your AC on recirculate or outside? I find recirc will get very cold if I leave it on manual.

It was set to outside/normal.
I have never used recirculate or Max Air. Other than adjusting the temperature down to 68° briefly, then back to 72°.
I've never found a reason to use max air.

 

[MavStangVa]

It was set to outside/normal.
I have never used recirculate or Max Air. Other than adjusting the temperature down to 68° briefly, then back to 72°.
I've never found a reason to use max air.

Thanks Glen. Never checked with a thermometer, if it feels cold I know it's working, lol.
BTW we did stop using that mechanic. It was about 25 years ago when my wife was using that shop due to me being on the road most of the time. Came home and he had charged her $90 labor to replace a halogen headlight bulb on a minivan ! I replaced the other side in less than a minute or two.

 

[MakinDoForNow]

The following AI synopsis agrees with what I found for Toyota years ago too.

It's not correct though regarding difference to ambient (unless they mean inside cab), because recirc mode should be on for the test. Therefore it's not ambient, but the air intake under the dash.
Same as HVAC tests in the house, return and supply are read.
Outside air temp comes in to play measuring line temp - and that's not happening in the truck easily, so doesn't matter unless you have a problem.

A properly functioning Ford truck AC system should produce vent temperatures between 40°F and 50°F (4°C - 10°C) when the outside temperature is around 90°F, ideally delivering air that is 30°F to 40°F cooler than the ambient air. Performance varies by humidity; however, temperatures above 60°F often indicate a need for service.

Ambient needs to be "qualified" as to inside or outside cab temp. Cab temp can be much higher than outside air temp excluding "chill factor".

 

[MakinDoForNow]

It was set to outside/normal.
I have never used recirculate or Max Air. Other than adjusting the temperature down to 68° briefly, then back to 72°.
I've never found a reason to use max air.

Max air is great for 1-4 minutes when cab temp is 95°-140°F (june-august)

 

[Glen Baker LLC]

Quite often when it's 110°-112° outside and the interior is 140°+. I find it more beneficial to roll a window down and exhaust the very hot air. Rather than trying to pull it through the system.
112° outside air is cooler than 140° interior air.
That's how I roll.

 

[HeyBales]

Quite often when it's 110°-112° outside and the interior is 140°+. I find it more beneficial to roll a window down and exhaust the very hot air. Rather than trying to pull it through the system.
112° outside air is cooler than 140° interior air.
That's how I roll.

I'll open the passenger window completely - then reverse with my door open to catch the cooler outside air and do a mass force exit from other side.
Don't need fast, don't need long.
Especially when son is there we appreciate getting that out fast - compared to how long it takes driving out and getting enough speed for the same effect thru open windows.
Warning and disclaimer - know your surroundings.
Of course if it's windy 2 open windows almost as good.

Ya - recirc'ing 120-140 F air with only a 40 F improvement is going to take awhile.
And that's what it does when the AC is pushed if you don't take recirc off.

Manual is not wrong!
Quickly Cooling the Interior

1. Press MAX A/C.

1. Drive with the windows open for a short period of time.

 

[MaverickDragon]

112° outside air is cooler than 140° interior air.
That's how I roll.

With inside air at 140F you are not rolling, you're baking in a convection oven...

 

[MavStangVa]

With inside air at 140F you are not rolling, you're baking in a convection oven...

But it's a dry heat

 

[MaverickDragon]

Reminds me of comment on a postcard my sister sent to out dad when she visited me in Phoenix.
It's a beautiful day in Phoenix. Sunny and 110 degrees, but with the breeze it feels like 115!

 

[Glen Baker LLC]

With inside air at 140F you are not rolling, you're baking in a convection oven...

But it's a dry heat

Dry heat vs humid heat
I think of it as a tolerated temperature range.
A dry sauna temperature ranges from 140° to 175°
A steam bath is usually kept around 110° to 115°
Yes dry heat makes a difference.

 

[JonP_Maine]

Temp settings on my Maverick are OK but a little wonky sometimes; weakest when projection from all 3 outlets (i.e defrost, feet, and center)

 

[rusty_shackleford]

FWIW I live in a hot, mildly humid climate. It is regularly 90F and 75% humidity in the summer mornings, 100F and closer to 50-60% in the afternoon. My XL works great on auto mode, I usually use 2 bars on the auto but on the days less than 80 I do one bar. I'll need 3 bars for a few minutes after parking in the Texas sun all afternoon. I'm not some weirdo who likes it warm either, I like it cold. I sleep in a 68F refrigerated bedroom.

If you think your ac is lacking, try going from ECO to Normal. I found out early on that ECO and Texas summers do not mix. The hybrid AC royally sucks when set to ECO, temp still climbing on 3 bars and it feels terrible with the sun beating down on the truck.

 

[rusty_shackleford]

I don't think, if I were you, I would return to that mechanic/ac expert.
Looking at it logically and realistically the expert doesn't make sense.
The picture below shows 117° outside. If what the expert told you was true. The interior air would only be blowing between 95 and 100°.
I can assure you that didn't happen. I was very comfortable at 72°

Even my thermometer shows the proper range for AC air.

I do AC for a living, the 15-20F delta is true, but not to outside air. That number gets thrown around a lot and misunderstood. That's the delta from the intake on the blower. A proper running comfort cooling system will run space temp minus 15 to 20, depending on humidity, coming out the vents. But thats for buildings, not vehicles.

Automotive AC has a couple more nuances, its more a refrigerator than an air conditioner from my observations, and has to maintain that 15-20 cabin to supply delta with hot fresh air being introduced, so the math changes a bit. If you could measure the actual air temp entering the evap coil, It might be a 40-70F delta T on a vehicle. To achieve this they are massively oversized for the volume of air they move, which works well to cool down a hot car. A properly sized unit for a refer box or a house would take hours to do that on a space as hot as a car.

Sponsored