Air Conditioning Help Please!

[ArcherV20]

I'm in the midst of buying an S14 with an S14 SR20DET installed already, the previous owner had not installed the A/C back into the car, I believe he has all the components from the KA motor, I was wondering what was involved in re-installing the A/C unit back into the car? I've really got no idea what to do when it comes to Air conditioning, so please help me out in baby terms.

Thanks guys. I appreciate it.

[inquisitorof240]

I might be able to help. An A/C system works on a pressure temperature relationship.When Pressure is high,temperature is high and when pressure is low the temp is also low. This is done with a Metering Device (controlled restriction) the causes a pressure drop in the system. Pressure is dropped before the Eavporator so that the Eavporator can draw the heat out of the passenger compartment and into the refrigerant,vaporizing the refrigerant. The refrigerant then goes through the compressor and then through the Condenser,Passing the heat to the atmosphere and starting the cycle over again. The hard part comes in finding out what kind of metering device (controlled restriction) it has. There are 2 basic types: The Fixed Orifice Tube (FOT) and Thermostatic Expansion Valve (TXV).The routing on these to systems is a little different. The FOT has an Accumulator/Drier mounted between the condenser and the Evaporator. The TXV has a Receiver/Drier between the Evaporator and the Compressor. Both of these both filter the refrigerant and remove moisture from it. The Accumulator/Drier is located in the high pressure side of the system while the Receiver/Drier is in the low pressure side of the system. This is one way of telling them apart. The other way is more involved so I won't go into that. The Accumulator/Drier is larger than the Receiver/Drier.

Reinstallation shouldn't be rocket surgery unless you don't have the evaporator installed in the dash. Then you gotta pull the dash apart. But as far as the routing, the condenser goes in front of the radiator, the evaporator goes in the dash and you gotta mount the compressor. Since the compressor cannot compress liquid, it must have lines routed to it before the condeser since the condenser condenses the refrigerant from vapor to liquid. Then you must route lines either from the Condeser to the Eavporator (TXV) or from the Condeser to the Accumulator/Drier and then to the Evaporator.

This seams complicated but its not so hard that you can't do it but it would help to have a certified A/C tech do the job for you. There is more to it than just the basics that I have covered. There are, for instance, sensors that need to be hooked up and then there's going w/ R12 or R134a. Anything '93 or newer came from the factory with R134a. If you have an R12 system, it would be recommended that you switch to R134a because no.1, It's more cost effective with R12 prices being $50 - $60 a gallon and no.2 it's more environmentally friendly. But no matter which refrigerant you choose, it is still against federal law to vent the refrigerant to the atmosphere so I would still recommend having a certified tech do the work.

If anything is unclear then just tell me what you need help understanding and I'll break it down a bit more for you to try to help you understand.