Absorption cooling

Maybe it has a chance if it increases gas mileage enough.

This seems like a bad idea to me. When you are not needing AC, the energy is unused. Better is something that uses that wasted heat to generate power of some sort.

I remember reading of devices that use exhaust heat to generate electricity.

Wikipedia:
An automotive thermoelectric generator (ATEG) is a device that converts some of the waste heat of an internal combustion engine (IC) into electricity using the Seebeck Effect. A typical ATEG consists of four main elements: A hot-side heat exchanger, a cold-side heat exchanger, thermoelectric materials, and a compression assembly system. ATEGs can convert waste heat from an engineā€™s coolant or exhaust into electricity. By reclaiming this otherwise lost energy, ATEGs decrease fuel consumed by the electric generator load on the engine. However, the cost of the unit and the extra fuel consumed due to its weight must be also considered.

Well, I was thinking that the refrigerator can cool the intake air when ac is not needed. That would allow an increase in compression ratio. What I havenā€™t thought about was deceleration fuel cut off. Then the car may roll miles downhill with no AC.

I guess formula 1 style turbocharge/turbocompound is the way to go. Some studies say that those f1 ā€œpower unitsā€ have achieved 50% efficiency

Keep in mind that refrigerators are only about 30% efficient. That means for every joule of cooling power, two joules of waste heat are generated.

Meanjoe, Iā€™m wide open to your explanation of the principles of physics that the system youā€™ve referenced operates by. We pedants not only like to pass on knowledge, we love to learn, too. :grinning:

The general principle is:

A refrigerant evaporates in a low partial-pressure area. The evaporation yields cooling.

It then moves into an absorber, which has something like salt water (and sometimes more noxious liquids) in it that absorbs the refrigerant to separate it from the other gasses in the mix.

Then you heat the salt water, which makes the refrigerant evaporate out again.

The refrigerant then passes through a heat exchanger and gets cooled down, condensing back into a liquid, where it goes back into the evaporator and starts all over again.

Youā€™re basically eliminating the compressor by instead using heat to drive the cycle.

Where does the heat go? What is it transferred to? If the refrigerant has been evaporated out, it must be cool. What cooler media is used to draw the heat from the cool refrigerant?

Jeeze, shadow, you robbed meanjoe out of his opportunity! :smirk:

Itā€™s transferred, eventually, to the surrounding air just like in a normal refrigeration cycle. Instead of being really hot due to a compressor squeezing the devil out of it, itā€™s really hot because you passed it through a fire. When it goes through the exchanger, it loses the heat you applied to it as well as the heat it absorbed in the evaporator.