134a discharge pressures

R410a is like any other refrigerant... it has to be charged by superheat and subcooling. The only real difference is that the pressures are approximately 1.6 times higher than R-22..... other than that, there isn't any "gettin used to". But if you had gone to any of the R410a classes put on by manufacturers and supply houses, you would know this.

I think it may be because 134a was developed to work most effectively in higher temperature applications. I can't wait for HFO-1234yf to replace 134a. I'm going to have problems remembering all those darn numbers and letters. Sir, I'm sorry to inform you that your refrigerator needs 2,3,3,3-Tetrafluoropropene. Let me get my environmental suit and breathing air tank. Hey, I get to charge more!

TDD

I'm sure 134a works a LOT better at medium and high temp applications. Well, it keeps ice cubes cold enough. Sure was simpler when we only had four or five common gasses. Now, we've got a real nightmare.

I never said that I wasn't qualified or licensed. I never indicated one way or the other. I may have been at one time.

Every time you open your mouth its shows you're not qualified and the last time I checked NY doesn't require a license which makes it easy for hacks like yourself.

Have you seen the new square and triangular shaped snap on connectors for the new refrigerants? The manufacturers are trying to make sure new and old refrigerants don't get mixed up.

TDD

Not seen those. Never know, might be a good idea. Or, more gadgets to haul around. Offhand, I think it's bad idea for techs like me.

Thinking some more about 134a. When I start up the box, the inside can be 70F or hotter. The system is designed for evaporator temps more like 30F. So, the supeheat is way off the charts. Helps explain the high discharge temps.

Ah, you're just sayin that to make me blush!

In hot kitchens or in older stressed equipment, I charge them with R-416a. It runs a lower head pressure than R-12 or R-134a and can be used in place of either. I've had very good luck with it.

How could any one miss those classes? They have free Pizza, pop, etc.

Thanks for the ideas, and information. One parts house near me has that. I've used 409a with great success. Advertised as a direct drop in for R12, with same mineral oil. But the

Busy fixing other stuff. I'll have to check at the parts house one day soon.

Not talking about a "subcooler", talking about *subcooling* where your looking for the Delta T between LLP converted to temperature, and actual LLT coming from the condenser. Normally for A/C and heat pumps, the Delta T should be between 10 - 14F to insure a solid column of liquid refrigerant to the TXV.

Johnstone stocks it in 25lb cylinders and in the small 9.6oz cans. The screw on can adapter has left hand threads if I'm remembering correctly. I have a 25lb cylinder and haven't used the small cans in a long while.

TDD

I used a small can of one of the R12 replacements that was specifically sold for use in household ref/freezer applications. I'm thinking it was

You'd have some really nice jugs, though.

The only time we change gas, is if the unit had R-12, and then we use 416a. The older units are designed for R-12, and the newer units come with R-134 in them. Not doing any conversions.

Never worked on a two stage cooler.

Both sound convenient. I've toyed with the idea of mickey mousing up a cantap for 134a, so I can carry a duplicate set of tools in my other Pinto. Sometimes I have to come back home for the Van Pinto. Most of the time, it's just cleaning condensors and electrical repairs.

I hear you, with the explosion of mixtures and blends. It's not like the old days. I've specialized a bit, and only carry a couple refrigerants in my work pinto.