Quote:
Originally Posted by undy
It's risky to "cook off" The dessicant. A by-product of that is the desicant pellets can break down, turning into a wide powder. It can contaminate an entire system necessitating a system flush.
There are two basic means of metering the refrigerant. The expansion valve, as you'd mentioned, and a fixed orifice (typically referred to as a "orifice tube"). The expansion does it's job by sensing the evaporator's tail coil temperature via a thermal bulb and regulating refrigerant flow via a variable orifice based on the coil's outlet temperature. The fixed orifice is "designed" for a given flow with certain assumptions and design characteristics in mind. The technical mission of the expansion valve (TXV = Thermal Expansion Valve) is to maintain evaporator superheat. (7 to 14 degrees, typically) I would suggest, with the many variables, that you use an expansion valve. The TXV (expansion valve) allows for a small amount of mis-match where the fixed orifice will not.. You should be able to find a valve to match the compressor with a little research. Some evaporator coils come with the expansion valve too.
I agree with Ronbo, ensure your oil matches the system/compressor manufacturer's recommendations. Always drain and refill oil prior to installing the compressor in the system. Get the system "sealed up" ASAP too.
I could go on, and on, and on...... 
Dave |
Good info,i appreciate it.This is where i sit:
System is open right now.Engine compartment is being painted,so everything is apart.Compressor is NFG,so that is going to be new.I'll oversize the dryer and then see about sizing a condenser.There is no valve under the hood-so if there is one-it's under the dash?