I have bought from Johnstone before. Online. Thermocouplers and them little millivolt generator thingamabobs for the gas log fireplace.I hope it don’t turn into that down here. Ive been going to Johnstone for the past 17 years because they are the best to do business with out of all the commercial/ Industrial HVAC houses around here. Cheaper for the same material to.
If I remember right, ES does not produce acid if moisture is in the mix. This is why, the mention of not having to pull vac on the system, I always pull down and deep on vacuum too.Only the OEM GM Refrigerant 134a switch I know of. Never found one for the ES industrial version: so for simplicity sake I suggest the regular stuff.
I pull a vac on the system. Not sure what moron came up with not doing that.
Otherwise a VOV and R134a is the safest way to go as it isn't flammable like the propane and butane these refrigerants are.
@THEFERMANATOR , do you know of a thermal switch that will go where the low pressure switch is in the dryer , is that where you are suggesting using one?You can use your stock R12 low pressure switch with the HC based refrigerants. Most R134 low pressure switches cycle off around 22 psi, if you look at that chart, 22 psi of r134 is equal to 26 for ES, and R12 low pressure switches happen to cycle off around 25-28 psi. It is best though with ES and a flooded evac to not use a low pressure switch, but instead switch to a thermal cycling switch where it has a temp probe in the evaporator core and uses a temp switch to cycle the system by actual evap temp instead of low pressure.
And your AC guy cannot charge a r12 to R134 retrofit by weight. There is no set rule of percentage of r134 vs r12 to charge by. And when installing aftermarket components, many times you have to adjust the charge amount even in newer cars because the replacement parts are not exactly like the oem parts were. This is why I always charge by temp whenever possible.
The thermal switch must be installed into the actual evap core, it cannot go into the line. The problem you run into wth the HC based refrigerants is they do not actually fully flood the evap. When charged fully they will still boil off some in the evap due to GM's flooded evap design. So you cannot fully go by low pressure. The 2nd best option would be to use an early style low pressure switch you can manually adjust it to cycle off at the higher pressure.