r407/410 leak

[philjd26]

hi,
if i have a leak on either of these refrigerant on a liquid line, would the blend be still intact and re-usable..?

rgrds phil

[The Viking]

Yes.



Or Maybe No.



Or it might.



It all depends on who you are listening to.

If it's only liquid that's escaped then I can't see how the mixture would have changed but we all take our chances and live with our decitions.

[Jimbo!]

I read that a topped-up R407C system would perform around 90% efficiency, even after multiple leaks - some academic study, I can't find it now unfortunately.

[Si@airconworld]

If you have a leak on a system - anywhere - blended refrigerants will change their... er.. blend!

In the case of R407c its made up of 3 different refrigerants which all boil off at different temperatures, therefore are in different molecular states and hence some will escape through the hole whilst larger molecules may be held.

Recaim it man, fix it, pressure test it - it'll save you the headaches later.

[marc5180]

I was taught that if the system had lost more than 15 or 20% of the total charge then it must all be reclaimed vacced out and then recharged with the correct amount.

[TRASH101]

Listen to si he makes good sense

If it is a leak on the liquid line the only time it is not going to noticabley alter the blend is if it is a big leak:eek: and that aint good either

[Thermatech]

On your system
When the compressor stops & the pressure equalises ,,,, will the liquid line then still be 100% liquid ?

After some refrigerant is lost & the system is running SOG will the liquid line still be 100% liquid ?

With R407c you have to suspect that the system is not leaking an equal measure of the 3 which make the blend even if the leak is on the liquid line.
So the possibilty is that you are left with an incorrect blend.
As the high pressure refrigerants will tend to escape first ( R32 & R125 ) you could assume a high concentration of R134a left in the refrigerant in the system & you might notice the system running slightly lower discharge temp & pressure after topping up. ( after you have first fixed the leak )
If the system has lost most of the refrigerant charge then whats left might be almost pure R134a.

[froidclim]

hello dear colegues
concerning the leak of r407c i have a 2 questions
1 what is the normal low pressure of r407c
2 can we use the leak detector as for r134
pls advise

[marc5180]

1) I would expect to see around 4.5bar on the low side when running correctly but there are factors to consider.

2) Yes you can use a leak detector on 134a.

[GXMPLX]

It all depends where the leak is. If it is in places where the mixture is at right compositions, it won't affect the mixture, like liquid line and suction line.

If the leat occurs in the midle of the evaporator or condenser it could affect composition.

If the mixture is not at the right composition you will get some variable out or range, like discharge temperature or capacity.

The only real way to tell is have a composition test on a sample of the mixture, and I've never done this.

So to be en the safe side you better recover/recharge but you can first give a try.

The leak detectors for HFCs need to be more sensible than HCFCs so you should check the manufacturer data.