I Know Nothing About Car Systems

[jeff88]

I am starting this thread, because sometimes during research, I come across something that I have heard of, but don't know how it works or I am driving and thinking about car stuff, but don't know the answer. So when that comes up, I will have somewhere to go to get the answer (assuming I can't find it elsewhere).

I'll start with an easy one: Why don't we use a refrigerant like R134A to cool the engine (through the radiator) rather than a coolant like ethylene glycol? Is there a benefit that EG has over R134A?

[cRiPpLe_rOoStEr]

Pressure, complexity and the risk of leaks.

[Daox]

Add cost to the list (kinda goes with complexity I guess).

[rmay635703]

Add safety, goes with pressure but 134a isn't exactly as environmentally friendly as sliced bread, antifreeze (take your pic of which) is an order of magnitude safer in multiple ways.

If you had that much 134a in one place and it let off it could cause inhalation dangers, not to mention pressure and environmental harm.

[rmay635703]

Makes me wonder though, could the AC system be "heat" powered off the exhaust, sans compressor?

Might be an interesting and very old concept.

[jeff88]

Originally Posted by rmay635703

Makes me wonder though, could the AC system be "heat" powered off the exhaust, sans compressor?

Might be an interesting and very old concept.

How would that work? Are you suggesting a turbo generator powering an electric A/C? Or maybe the exhaust drives the pulley like a belt?

[bryn]

good luck, should work just fine. Absorption refrigerator - Wikipedia, the free encyclopedia

[cRiPpLe_rOoStEr]

I've already considered to use some sort of absorption refrigeration setup to recover heat from the engine itself and the exhaust and to use it both for intake cooling (with a coil inside the air intake to act like an intercooler) and as a replacement for a regular air conditioneer.

[jeff88]

Any reason why I couldn't use propylene glycol instead of EG? It doesn't have as low of a freezing point, but I don't really have to worry about that in this weather! Is there another reason why I wouldn't want to use it?

Also as a side note, why do we not use oil as a coolant? (I know that the engine oil does help with cooling, but I'm not talking about that). Couldn't one use a really thin, maybe 0w-10, oil in a coolant loop? I would think (and read) oil is a better vehicle for heat pick-up and removal.

[Ryland]

Originally Posted by jeff88

Any reason why I couldn't use propylene glycol instead of EG? It doesn't have as low of a freezing point, but I don't really have to worry about that in this weather! Is there another reason why I wouldn't want to use it?

Cost is the only reason I've found, some people do use it.

Also as a side note, why do we not use oil as a coolant? (I know that the engine oil does help with cooling, but I'm not talking about that). Couldn't one use a really thin, maybe 0w-10, oil in a coolant loop? I would think (and read) oil is a better vehicle for heat pick-up and removal.

Again, cost, it would cost you $52 per gallon, oil also it gets thicker when you cool it so you'd need larger passages in the radiator so you'd need more of it and thus more cost and weight, air cooled VW's had oil coolers on them, some motorcycles do as well, but in general they all run much hotter and their cooling is not as even.