No, the low side pressure varies with the Delta-T just as the exit temp does.
Adding the pressures to my example above:
70% Humidity:

Ambient Temp: 90°F, Exit Temp : 67°F, Low Side Pressure 61 psi, High Side: 260 psi
Ambient Temp: 80°F, Exit Temp. 56°, Low Side Pressure 42 psi, High Side: 215 psi.

http://www.toyota-4runner.org/attach...temp-chart.jpg

It's basic conservation of energy. You make it easier for the system to throw heat off the front, the more heat it can suck off the inside. The phase change from the evaporation eats up a pantload of heat from the front of the system.

Put a layer of this between the head liner and roof. Big difference.Reflectix, 24 in. x 100 ft. Double Reflective Insulation, BP24100 at The Home Depot - Mobile

I agree with "TheDurk". If we can cool down the condenser, the refrigerant can absorb more heat from the cabin and release it at the condenser, making the cooling process faster.

One gram of water takes 1 calorie (4.184 Joules) to raise its temperature by one degree Celsius. So to bring it to the evaporating temperature (100 Celsius), it will absorb quite a lot of heat from the condenser. This makes the condenser to rid more heat from the refrigerant before it exists from the condenser.

Yes, I will need to use DI water for this purpose and this system will only be used at the initial cooling.

I thought about having some kind of sheet above the roof rack to block the sun rays but then it will cause a heavy drag due to a narrow space to escape air diverted by the windshield.

Basically, you are tacking a swamp cooler, aka evaporative cooler, on to the front of the A/C system to boost its performance.

https://en.wikipedia.org/wiki/Evaporative_cooler

Why water? I mean, if we're goin balls out here, why not use liquid nitrogen?

I got all these covered! Thanks!

Anyone ever thought about a bigger blower fan or a bigger motor.

I even have access to liquid Helium!

Cashmoney, I think a bigger blower fan will be a good idea. Problem is the room.

...because...

In kJ/kg
Water 2260
Nitrogen 200
R-134a 215.9

https://en.wikipedia.org/wiki/Latent...f_latent_heats

You had to ask....

OK, so from what I've read in the last few minutes of googling. It seems the BIGGEST benefit is the efficiency of the compressor when water cooled. I doubt we would see any real world fuel mileage increases unless you live in Phoenix and run the a/c 24/7. I'd love to see a real world test to see if the cooling can lower the in cabin temp significantly quicker with the water cooling on the condenser. All in all, this is one of the best threads I've encountered here, I am humbled in Y'allz presence.

Who said it would help mpg? I missed that. I agree that's a stretch. Maybe, if the period of continuous running on initial start-up was shorter, there is some economy, but as it only happens once per trip, it's de minimus, if it exists at all.

I'm in AZ and as everyone knows the summers can be brutal. I've been thinking abut ways to assist the AC in order to make it more efficient, so I'm glad you posted this.

I think an efficient dedicated fan for thr condenser would really help. Maybe you could setup a mister that sprays only when you are at idle or in park. And I'd probably say go with a finer mist so you can cover more area while using less water.

I really like the idea of insulation under the headliner. I probably need to do that.

The MPG was my own extrapolation, based on the efficiency of water cooled condensers on rooftop a/c units. That was why I figured in a constant heat like AZ, you could benefit from water cooling during more of the operation, and potentially run the compressor less and see a mpg benefit. It would be minuscule at best, but probably does exist, maybe.

The fan would certainly help. My son's BMW e36 323i has an electric auxiliary fan mounted in front of the condenser (a 'pusher') in addition to a conventional belt-driven fluid-clutched 'puller' mechanical fan like ours behind the rad. The aux. fan only engages when coolant temps exceed a certain level, but it also engages full-time whenever the A/C is running.



It wouldn't be that hard to fit one of these on our trucks, it's about the right size and there are aftermarket suppliers at a reasonable price--if you felt the need.

HOLY Airplane propellers Batman!!