Top up or replace refrigerant

[chillyblue]

Hi

At what point do you make the decision if a system has lost part of its refrigerant charge do you decide wether to reclaim the gas or top it up??

Cheers

CB

[The MG Pony]

dependson the gas I would say. Either way the reason for the loss has to be fixed befor any of the choices become an option.

[Latte]

CB,

Of you are on a gas handleing course then every time you reclaim the remaining gas, leak check with ofn, fix leak, retest, vac and gas.

Now in the real world, you are not going to reclaim a supermarket pack each time a ball valve leaks

Due care, attention and common sense is the nearest to an answer i can give you, there isnt a black and white answer it just depends on the system size and if you can find a leak or not.

I guess this doesnt answer youre question but all i can say is the official line is as the first paragraph and where you decide to go from there is up to you. Remember gas is classed as a hazardous waste, the powers that be dont seem that interested at the moment but i suspect sometime in the future they are going to start looking at the big boys to see what they do in these sorts of cases

Regards

Raymond

[lana]

Hi,

Zeotropic refrigerants with high glide need to be reclaimed. If leak occurs the remaining refrigerant will not be the same as the original one.

However, lots of research have been done about this issue and for each refrigerant there are some tests and recommendations. For example one test shows that if 50% of R??? leaks and the remaining refrigerant is not reclaimed and new refrigerant is added then the composition does not change and this can be repeated for three times.
Of course these figures are a sample and this differs for each refrigerant.

Another case is this. If the leak is in a place where there is a super heated gas, sub cooled liquid then there is no need to reclaim. But if the leak is in the evaporator and the condenser (two phase area) then you need to reclaim.

Hope this helps
Cheers

[chillyblue]

Hi,

Zeotropic refrigerants with high glide need to be reclaimed. If leak occurs the remaining refrigerant will not be the same as the original one.

However, lots of research have been done about this issue and for each refrigerant there are some tests and recommendations. For example one test shows that if 50% of R??? leaks and the remaining refrigerant is not reclaimed and new refrigerant is added then the composition does not change and this can be repeated for three times.
Of course these figures are a sample and this differs for each refrigerant.

Another case is this. If the leak is in a place where there is a super heated gas, sub cooled liquid then there is no need to reclaim. But if the leak is in the evaporator and the condenser (two phase area) then you need to reclaim.

Hope this helps
Cheers

Thanks
It was Zeotropic blends that i was refering too. prior to refrigeration blends, the leak was found, repaired and then topped up with refrigerant, now everybody says that if the system has leaked, you must reclaim the remaining gas and recharge. doing this is at a big cost. if a plant has lost 50% charge, then they get charged to reclaim the remaining 50% and the 100% replacement, where as before they would have just paid for the extra 50%.

by the way i have got my safe handling C&G's, just checking the real world.

R410a is very dear to supply and reclaim.

Cheers CB

[marc5180]

Hi

At what point do you make the decision if a system has lost part of its refrigerant charge do you decide wether to reclaim the gas or top it up??

Cheers

CB

i was always taught that with zeotropic refrigerants like R407c if it had lost more than... i think it was 15 or 20% of its charge then it should always be reclaimed and replaced with new 407c

[airconadam]

iwas also told the same as marc. but another question is what if you only have to put say 5kg of 407c out of a 10kg bottle in a system, how do you know you have got the correct amount of each gas out of the blend if you know what i mean thanks alot

adam

[Lowrider]

That's why you have to charge as liquid!!!!!!!!!!

[Brian_UK]

That's why it should be a liquid charge.

[Brian_UK]

-- Snap --

[Lowrider]

-- Snap --

Too much explenation points?

[Brian_UK]

Too much explenation points?

No, I just meant we both hit the send button at the same time with the same answer. An old childrens card game..

[Lowrider]

Try doing that a second time! The odds on wining the lotery are better!

Also "wasting" time before going to bed?

[airconadam]

ialways charge as a liquid but can you not charge more of one of the blend than the other ie again if u only charge 5kg of a 10kg bottle thanks alot

adam

[Brian_UK]

No, the blend is in the liquid.

When it is vapour then you will get the different elements.

The amount 'unmixed' in the bottle is not worth bothering with unless you're talking 63kg bottles or larger when near the end of the liquid volume.

[airconadam]

ah rite iam with you brian thanks alot once agian hehe

adam

[paul_h]

I normally reclaim and recharge with blends, systems with a definate weight charge given eg, it's capillary system.

The bottom line is who's going to pay for it if you don't?
For example, a system has a leak, you're called in, fix the leak and charge 1kg of refrigerant to a 5kg system. Afterwards the customer calls you back, saying it's icing up, doesn't perform as good ever since YOU repaired it. They regret ever paying your $200 bill, plan on legal action etc. You've already wasted heaps of time on callbacks for a piddly $200 bill, they expect you to reclaim and recharge free of cost. In the meantime they call someone else instead, that tech tells them that you were stupid to top up, gives them a $400 bill for reclaim and recharging, and after that they use him and recommend him to all their friends as the smart fridgey that got it right, and say you were the bad one.
What are you trying to do, save money for the customer? Doing that means you might break even, but you'll never gain from it, it will bite you in the arse enough to do more damage than good. The customers need to be told how much something is worth to do it right. Let them find out the cheaper way has more problems, be the second guy in my example that charges more, but gets the recommendations.

edit: For a large ducted system on r22 though it's fine to 'top up' (after you find the leak that is )

[fridg]

Here in OZ it is illegal to top up a system , if it is low on gas there is obvisouly a leak , and the Department of Enviroment and Heritage here that supplies our handling licence states " it is illegal to knowingly release refrigerant to the atmosphere"

Only an inert gas can be used for this.

And now that you have to record every gram of gas used , to monitor emissions , the paperwork will eventually lead back to you , resulting in a fine or the loss of your licence , which in turn will not allow you to buy refrigerant or handle it.

[chillyblue]

Hi

The reason i asked the original question was, the other week i was working on a 25KW VRF system that has 22KG's R407C in it, i suspected a leak and reclaimed the refrigerant into a special clean reclaim reciever, supplied by HRP, the amount of gas reclaimed was 18KG's, so i was right the system was 4KG's short.
The system was pressure tested with OFN and the leak was found, a cracked flare nut on the exit pipe from one of the selector boxes, as you rightly said it is illegal to put refrigerant into a system which is not known to be tight!!
Now back to my original question, do i refill the system with virgin R407C, and hand my client a bill for 22KG's or do i / can i return the 18kg's from the relaim reciever back into the system and top up with a extra 4kg's of virgin R407C??(makes sense to me)

To fill the system with completely new refrigerant on a plant of that size seems an awfull waste and excess cost to my client.
If the plant was a small A/C unit with a charge of 1KG, i would'nt hesitate in changing it with new refrigerant.

Also what happens when you have a plant with 60KG's in it?? every time you have a leak (may only be a couple of KG's) do you reclaim it all and refill it with new refrigerant?? and hand the client a bill for 60KG's i can't see many people doing that!!

I quote to my client your plant lost 2KG's but here's you bill for 60KG's, i can't see me getting a very good repertation that way either

I've seen it before and i can hear it now,
Client say's " i had this company in the other day, my plant had lost 2 KG's of gas and he wanted to charge me for 60KG's, so i got someone else in and they topped up with 2KG's and its as good as gold, and cost me next to nothing. The firsat bloke must have been a right robbing B~stard

Cheers

CB

[paul_h]

Well, I don't really work on units with more than 6kg charge these days, so it's less than an issue for me. I actually posted in a similar thread that if it's more than 6kg I may reclaim into a verified clean cylinder.
If it was a large enough charge to cost more than a few hundred $, and I used clean everything, (like drier on the reclaimer line, oil-less clean reclaimer and cylinder, changed system drier, and only liquid charged to minimise incondensibles going back in).

But even then I would be reluctant to do if for blends. It's all about percentages really, if a system that takes 22KG of a blend is 4kg short, well than that's a fair risk to take and I see your point. As someone mentioned earlier, there is percentage values given as limits for lost refrigerant.
I've been mainly doing small commercial and domestic stuff, so I think in a certain way these days.

But if you do top up, it should be explained in writing that if there's performance issues, a full recharge will be done at the customers expense.
If you're making financial desicions for the customer, you should explain it to them so they understand beforehand. EG, "this should work, and if it does you'll save heaps, if it doesn't it will cost you more in the long run".

[chillyblue]

Thanks for the reply Paul

Chilly Blue

[zolar1]

If you called ICOR regarding R414B about this, their reply might be this:

Low side loses the R22 component, and the Liquid side loses a uniform mix.

It's been a long time since I called them, but I seem to remember the 20% rule: if you lose 20% or more, reclaim and replace.

Then, let the reclaimed amount sit for 24 hours, drain off noncondensibles, and check pressure & temp against a P/T chart. The manufacturer should be able to tell you approximately what part(s) of the blend are missing.

Again, it's been a LONG while.

[Samarjit Sen]

A similar thread is on the RE and my suggestion is that in such cases for the sake of the oerformance of the plant, the system should be charged with a fresh charge.

[unloadedinher]

Hi Chillyblue

I personaly would reclaim all refrigerant if its a mixed blend, if not it can cause pressure differential problems, only with R22 i would top up.

R410a Is a no no for topping up.

[Lowrider]

Hi Chillyblue

I personaly would reclaim all refrigerant if its a mixed blend, if not it can cause pressure differential problems, only with R22 i would top up.

R410a Is a no no for topping up.

And why so? R410a has almost no glide (R32 boilingpoint -51,7 dgrC R125 boilingpoint -48,5, both at atmospheric pressure!) Mixed and under pressure glide is near to zero! So in case of any loss both will be released!