134

[joe1975]

I'm wondering why the 134 in todays cars cool so much better than the conversions even in whole new aftermarket systems stopped in traffic it seems like there not working at all

 

[Bill75]

The 134a has higher vapor pressure than the R12 and is only 80% as efficient as the R12 in a converted system. In a car that had marginal cooling capacity from the factory to begin with the 20% loss is significant.
I assume by whole new aftermarket systems you mean something like Hotrod Air offers, in that case it sounds like the system is undersized or doesn't give good air distribution if it isn't working right. I've seen a few comments about the Hotrod Air conversions and people seem to like them very well and have commented on what good a job they do. You might turn up some comments here doing a search on the name.

Bill

 

[JohnZ]

The OEM systems in modern cars are designed specifically for each application, with properly-sized (larger and more efficient) condensers, better refrigerant control systems, and more flexible and effective discharge air distribution systems. They're developed and tested under the most extreme conditions imaginable (including the engine cooling system), and are extremely reliable, with no concerns about low-speed cooling performance or overheating. Almost all are "re-heat" systems, which allow very precise (and frequently automatic) discharge air temperature control.

Aftermarket systems are far more generic, and not as thoroughly developed; they require some adaptations for different applications, and matching the engine's cooling system capacity to the additional cooling load imposed by the condenser becomes a customer-engineering exercise. Properly adapted/engineered/installed, they can be very effective, although almost all of them only operate on recirculated (inside) air, and none are "re-heat" systems, which makes refrigerant and air discharge temperature control difficult.

When I built my Grand Sport ten years ago, I installed a Vintage Air "Supercooler" R-134a system, and you could hang meat in the car, but you also had to accept the system's temperature control limitations (temp control via fan speed).

 

[joe1975]

I put a aftermarket in my Jeep didn't work that well. My vette system seems to have loss it's freon now I've gotta find someone who knows how a older system works. good helps hard to find

 

[Tom73]

I'm wondering why the 134 in todays cars cool so much better than the conversions even in whole new aftermarket systems stopped in traffic it seems like there not working at all

The new systems are designed to work with 134. They have larger evaporators and condensers to allow for the reduced cooling power of 134. The old systems were designed for R12 and do not have enough capacity for 134.

tom...