Why can't I top up my R407C air con with R134a

[sturgm]

Hi,
I own a air con system that is charged with R407C, a beer cooler charged with R134a, and a heat pump charged with R22. What is stopping me from topping up all the systems with the same R134a.

I am sure that to most of you guys this is a dumb question but that's why I am asking it. I just don't know why.

Thanks

[NoNickName]

Hi,
What is stopping me from topping up all the systems


The Law. You simply can't.

[The Viking]

Don't worry, ofcourse you can use the same gas in all of them.


It would, as previously stated be against the law and the units designed for other gasses wouldn't run very well but apart from that there ain't no problem...


I know I said this before but I will say it again.

Find a suitable qualified, experienced engineer and follow his/her advice.

There really ain't no shortcuts.

[tonto33]

must be a norfolk thing as i get same questions asked all over norfolk, i love it here..pmsl

[expat]

After telling someone all the reasons why we couldn't use some old 5/8 copper he had kicking around he asked me if we couldn't just rince it out with soapy water.

He actually even got offended when I laughed out load.:)

[sturgm]

Thanks for the replies. However I was expecting some more technical reasons such as laten heat of evaporation is not compatible or vicosity of lubrication oil disparity or seal degregration....

Also there seems to be a large'ish after market for DIY auto recharges kits (I bought one) that all work really well. So why not for small aircon units etc?

[The Viking]

OK, some points to get you started.

1. R22 operates with mineral oil. This mineral oil will not lubricate well with modern refrigerants. (Put R134a in to that system, without changing the oil, and the compressor will fail)

2. The different refrigerants have different temperature/pressure relationship and requires different condensors+evaporators+controls.

The problem nowadays is that kit (both units and service gear) is easily obtainable for anybody.

Knowledge that takes years to gain are bypassed by "happy go lucky" DIY people and then they wonder why things go wrong and are expensive to repair.

[The MG Pony]

different piston displacements for the different gasses and such.

Tell me, would you top off your petrol truck with diesel? After all they both burn! ;)

[paul_h]

Thanks for the replies. However I was expecting some more technical reasons such as laten heat of evaporation is not compatible or vicosity of lubrication oil disparity or seal degregration....

You didn't get technical replies because it would be:
a) Filling your head with meaningless terms that wouldn't explain it too you anyway* because...

b) If you didn't know that different refrigerants behave differently, have properties suited to certain temps, require different compressors, TX valves and oil, and...

c) Couldn't be bothered looking it up through all the resources available here and elesewhere on the internet, it would be a waste of time trying to give you a run down on everything in the short space of one forum post. Because seriously any in depth reply would just make your eyes glaze over and look for a yes or no answer, and you'd never give a damn about the time taken to explain it to you, because...

d) If you really wanted to know, you wouldn't ask this question without doing some research yourself. You want to be spoonfed and told why, just like someone who isn't really interested in the details, but wants simple answers, and that's what you got.

edit: *seriously, no offence, but why would you expect to be given technical answers if you show no technical aptitude yourself? Not an insult but most people would save the technical stuff from someone asking such a basic question as it would probably confuse and be a waste of time.
Why would you expect to have the knowledge of all refrigerants after making just a few posts on refrig-eng? Technical answers are wasted on the non technically minded people who aren't interested in doing their own research/work.

[expat]

sturgm, I'm afraid that with your obstinance I will have to use the technique I use with my 7 year old son.

You musn't do this because:

1. IT IS AGAINST THE LAW!

2. IT WON'T B****Y WELL WORK!

Sorry for shouting:mad:

[The Viking]

Before you post any more replies, please have a look HERE (http://www.refrigeration-engineer.com/forums/showthread.php?t=11290&highlight=ethos).

Sturgm, I'm sorry for the harsh welcome you got, I do apologise.
But I think the points raised are valid, even if the tone could have been friendlier.
My personal belief is that the person/company that sold you the car A/C "recharge kit" were wrong in doing so. There is a reason why most of us here has gone through an apprenticeship. (Yes, I also think that DIY installs should be banned)

In recent news they were talking about polar bears drowning and I for one would like my daughter and her children to have a habitable planet.

To a DIY person it might seem like if you can redo the plumbing in your bathroom, then you should be able to install an air condition system. Or at least that what the people pushing cheap A/C units would like you to believe.
The problem, as most of us on this board knows, is that this just isn't true.(most likely, there are also good reasons why said people can't sell their kit to professionals and instead has to target other groups)
But all of us with time served in this industry will be able to tell horror stories about DIY jobs gone wrong.

Whatever you decide to do, good luck.

Peace and love everybody.

[expat]

Viking's right, I went over the top a bit. Hey, we have bad days.
Thing is though his points are unavoidably valid. You are not going to be able to sort this out yourself. And, please, don't start mixing different refrigerants.
That is done by people with a profound understanding of chemestry,...and they still get it wrong. What do you think you will do?

[sturgm]

Well, what can I write? I have viewed and contributed to a variety of forums over the years covering many and varied topics CNC routing, Woodworking, Computer programming and just general topical advice. All have been informative and by and large helpful and understanding. I do appreciate and understand that this is a specialist topic but in these days of complexity what is not specialised. I can remember when I could lift up my car bonnet and know most of the parts intimately, alas not anymore. I retired some years ago in my 40’s after a successful career in the very specialist arena of IT. I fortunately had a skill where I could explain very complicated concepts in more simple terms to most people in a meaningful way that was not patronising. This enabled these people to appreciate the complexity of the problems without really understanding the detail, which in all fairness was not a requirement. I still have a very enquiring mind and to have it snubbed out by what I can only think are small minded insecure people is quite sad. As I wrote in my first post
‘I am sure that to most of you guys this is a dumb question but that's why I am asking it. I just don't know why.’

Anyway this certainly is not the correct use of a forum on refrigeration unless in this forum a post is obligatory no matter how offensive. I will in future just restrict myself to viewing only.

Oh, one last point though. Being an expert in everything must be quite a burden to carry in life never having to ask, what would be considered by some people as dumb questions.

Regards Mike

[Chef]

Interesting.

Sturgm - if you find this friendly and informative forum a stretch and think you have been ill inormed, which of course you were not, why dont you visit PhysicsForums.com and ask a question (even the same question). They will put you straight. You are an IT expert so you should be able to find it easily.

Do you dare? I doubt it.

Chef

[The MG Pony]

You must understand in our industry how much kit has been distroyed and damage don by people doing just as you asked about, at least you asked!

Thuse all the built up annoyance comes out!

but to put it in simple technical terms look at my Q, would you use diesel in your petrol truck? They both burn after all ;) Becuase you know they are differant and requier differant systems to burn right! Just as in refrigeration!

[fridge doctor]

Good reply Paul h, I second that.