Why is absorption AC not used in cars?
 

It seems like ICE cars would be ideal for using an absorption AC system, given all the waste heat. But I've never heard of a single manufacturer using it. There must be some gotcha I'm missing.

For instance, my work uses this type system to provide AC from steam:

https://www.lg.com/global/business/a...ler-steam-type

Absorption AC would basically be "free" in terms of fuel consumption.

Without knowing about the system, I'd guess it's a matter of size/weight and responsiveness. That, and being able to defrost immediately, even before the engine warms up.

Very cool idea though. I'd be interested to see where and how it has actually been applied.

Absorption systems are big, bulky, expensive, low power density.

More importantly for the “efficient “ refrigerants
A leak can be deadly,

Who wants a giant fog of ammonia if you puncture the system?

Find an efficient, lightweight, non-hazardous, non-coorsive active fluid and you would see “free “ heat based AC in cars.

Photovoltaic cells in “hot” regions of the country would make massive amounts of free ac but very few have explored low temperature adsorption air conditioning.

Nothing wrong with massive amounts of cool air instead of a small amount of cold air.

Ah well

Oh deadly refrigerants are standard now.
What's that new one that's replacing r-134a, I think it's hfo-1234 or something like that.
It immediately breaks down to hydrogen fluoride and some other lovelys upon contact with air.

No reason not to then, a small adsorption system off the exhaust could easily run cooled seats at a relatively low cost.

Enter the danger zone, oops tore a seat.

AFAIK they were quite compact, yet usually not much efficient for residential fridges. Odd enough, absorption fridges tended to remain popular on hotel and hospital rooms because they were more silent than a compressor-driven fridge.

why no absorption cycle
 

Some of my neighbors are still using refrigerators which use it.
They're horrifically inefficient, as far as input energy per net cooling effect.
Some use anhydrous-ammonia as the working fluid, deadly poison if it leaks.
'Industry'-scale Lithium-bromide chillers are boot-strapped onto the waste-heat side of natural gas-fired turbo-generators for refrigeration ( AeroStealth operated one by Solar Corp., at the University of New Mexico, at Las Cruces.
They'll also run off flat-plate solar collectors.
They're only for 'stationary' applications. No G-forces allowed.:p

Last time I saw absorption fridges was in some old motorhomes. Odd enough, I've never seen absorption air conditioners not even in motorhomes.

air conditioners
 

My parents home in Lubbock, Texas had an Arkla-Servel, gas-fired, ammonia refrigeration cycle air conditioning system from the 1960s, cooling 2,400-sq-ft.
Aside from a pump moving a glycol coolant to and from the A-Coil, it was just an overgrown version of the RV, dual-mode refrigerator.