AC help, taking a long time to get cold in very hot temps

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So my AC works great in normal warm temperatures, fires up cold right of the bat and is ice cold. But now that we are getting triple digit temperatures it takes like 10 minutes to get ice cold. I also have another buddy 80 owner in town who is experiencing the same issue. Any help would be appreciated. Thanks in advance.
 
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after driving or when from parked just in triple digit? these engine bays get heat soaked and it can take time to get cold... do you have a modded fan clutch?
I don’t have the modded fan clutch. It happens from when the truck is parked in the heat only. It takes nearly 10 minutes to get ice cold after running and the thermostat reads fine for the engine temp.
 

enox

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Yeah it could still be heat soak on the condenser.

I'm not an AC expert, but I was recently in 100°+ weather, when I stopped and parked I left the aux fan on, also my fan clutch has 20k cst weight oil in it. My AC blows at 40° - 46° in those temps and is cold when I start it.
 
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Have you put a thermometer on your interior vent and see what temps you are getting? Your system might not be running optimal if your expansion valve or any of the other small Orifice is clogged you won’t get 100% performance. My truck blows same as Enox 40ish and with the 100+ temps it takes a little to cool down but not ten minutes.
 
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Have you put a thermometer on your interior vent and see what temps you are getting? Your system might not be running optimal if your expansion valve or any of the other small Orifice is clogged you won’t get 100% performance. My truck blows same as Enox 40ish and with the 100+ temps it takes a little to cool down but not ten minutes.
Have not, but it blows ice cold when I start her in the morning. It’s after sitting in the sun when the problem begins
 
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I really think the components under the dash and inside the car are just getting that hot. Imagine the amount of heat your carpet and seats hold even after you turn the AC on. It takes time to cool all of that stuff back down. Try parking your car in the shade in the same triple digit heat and I'm sure you'll notice a difference. Its not just the air temps that's causing your problems. Its the sun's rays.

Every time my cars are parked outside the sunshield in the windshield gets setup. Keeping the UV off the dash helps in the long run as well. If I'm going to be parked for a long amount of time on a hot sunny day then all of the sunshields go up. Proper window tinting helps a ton also. Ceramic tints are the go to stuff these days. Many of the very light (almost clear) ceramic tints block just as much heat as the older 5% dyed window films. So imagine what a 30% ceramic would do to cut down on the heat energy being put into the interior. Now imagine insulated sunshields on all of your windows that block 100% of the light coming through.
Cruiser Sunshields.jpg



or you can own an audi that has a solar panel in the sunroof to run the blower fan to keep fresh air circulating inside the cabin.
 
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Yeah it could still be heat soak on the condenser.
I'd like to add to your comment that i live 2 steps outside of hell, where last week it was 117 degrees in the shade, so i have alot of experience dealing with AC's not blowing cold. The thing he's forgetting about, is when he parks his truck in the sun, the WHOLE interior of his truck becomes a huge green house heat sink. So it's going to take awhile to absorb, and then exchange all that latent heat from his interior, before his AC starts blowing cold.
 

enox

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I'd like to add to your comment that i live 2 steps outside of hell, where last week it was 117 degrees in the shade, so i have alot of experience dealing with AC's not blowing cold. The thing he's forgetting about, is when he parks his truck in the sun, the WHOLE interior of his truck becomes a huge green house heat sink. So it's going to take awhile to absorb, and then exchange all that latent heat from his interior, before his AC starts blowing cold.
Very good angle, thanks for pointing that out. Makes a lot of sense!
 
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Very good angle, thanks for pointing that out. Makes a lot of sense!
Remember your AC is just removing heat. It not just blowing cold air, its blowing air that lacks heat and it has to remove all of that latent heat Rifleman mentioned. The AC system is just transferring the heat to the outside from the evaporator to the condenser. Work to minimize the heat load inside the car... assuming your AC system is working properly.
 

flintknapper

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I'd like to add to your comment that i live 2 steps outside of hell, where last week it was 117 degrees in the shade, so i have alot of experience dealing with AC's not blowing cold. The thing he's forgetting about, is when he parks his truck in the sun, the WHOLE interior of his truck becomes a huge green house heat sink. So it's going to take awhile to absorb, and then exchange all that latent heat from his interior, before his AC starts blowing cold.

^^^^^ 👍

This is precisely the issue. The aggregate 'heat load' from solar gain is what the system must overcome. It takes time.

There must be quite a few 'heat exchanges' for this to happen.

Many folks misunderstand how A/C works. You are NOT importing cold air. You ARE removing heat from the cabin. Heat is absorbed into the refrigerant *by means of the evaporator*, that latent heat is released by the condenser and the exchange starts all over again.

The reduction/absence of heat in the cabin is what we think of as 'cooling'. At some point the evaporator itself will indeed become cool enough that the air blowing over it will result in cold/cool air coming out of the vents....BUT the interior of the vehicle still contains many BTU's of heat that will need to be removed.

So on extra hot days....be patient. Or better yet, take steps to insure the interior of the vehicle doesn't get 'scorching' hot to begin with.
 

flintknapper

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Remember your AC is just removing heat. It not just blowing cold air, its blowing air that lacks heat and it has to remove all of that latent heat Rifleman mentioned. The AC system is just transferring the heat to the outside from the evaporator to the condenser. Work to minimize the heat load inside the car... assuming your AC system is working properly.

Correct. You type faster than me....;)
 
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Looks like you have it all nailed down, but some additional tips from Phoenix;

1) tilt your sunroof and open the slider about an inch. This let's out some hot air which will rise to the roof interior.
B) lower your side windows about an inch to promote cross-flow with any breeze. This helps to prevent storage of superheated air inside the vehicle.
III) park under a tree, or otherwise park further out where there is some / any shade at all. Here in Phoenix, it's not about proximity to the front door, it's about shade where you parked.
Four) everybody has a Heat Shield on the front, and tinted windows everywhere else. Anybody who doesn't has out of state plates...
5) get in the habit of rolling ALL of your windows down when you first get in and start driving. This evacuated the super heated air and let's your AC work a little easier, arguably.
F) get a spray bottle and fill it with alcohol. When you first get into your LandCruiser, give the interior air a spritz or two or twenty. The heat in the air will be reduced by having to vaporize the tiny droplets of alcohol, thereby dropping the air temp almost instantly.
Seven) paint your LandCruiser white. There's a reason why the Phoenix guys claim white is the official color of 80s in this state!
 
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*forgot to specify; works better in low humidity environments, but yeah - it does work really well.

The physics behind it has to do with the energy required to change the state of the alcohol from a liquid droplet to a gas. This eats the heat energy out of the air instantly, and while it won't drop the air temp to cold, it will remove that heat before your AC has to pump it out.

Try it and report back. The specific heat of alcohol is less than water, meaning that it should evaporate (*change state) faster so as to not cause mugginess.
 

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