View Full Version : does an air condition loose a lot of oil during refrigerant removal?

03-04-2017, 09:44 PM
I am in interested in listening your opinions about that subject.
I have a split a/c which its refrigerant (R407c) was gone out to the thin air.
probably the former technician let it out on the air.

the question is if that a/c has lost a vast amount of oil ,(during the exertion of refrigerant through hoses), so as to cause problem to compressor after re-filling it with new refrigerant?

some techs in Greece believe that adding oil to a split a/c can cause capillary blockage.
they assume that if a small amount of oil is lost, try not to add any oil otherwise you will cause troubles.the compressor has enough oil in its carter and only a small amount of oil circulate through the split a/c cycle.
what is your opinion?

03-04-2017, 10:51 PM
I agree with you sir.

04-04-2017, 07:15 AM
The only access to a split system is the 1/2 inch service valve on sunction line.

04-04-2017, 12:40 PM
To make it more plain,the issue is that an a/c split system does not have a receiver or accumulator.
As a result when you add oil through th service port,the compressor pumps the oil directly to the high side pressure.
The capillary may be a severe restriction for the pure oil circulation.

04-04-2017, 06:21 PM
Adding oil via the suction side will simply put oil into the compressor sump.

04-04-2017, 08:27 PM
What is your pipe length...is it in excess of the manufacturers recommended length?

Is the condensing unit above the indoor fan coil?

Are you getting good air off temps on the indoor unit?

You could have oil logging in the indoor unit

04-04-2017, 08:39 PM
The pipe length is 3,5 metre between indoor-outdoor.
The outdoor is below the indoor.
I have complaints from technicians that inserting oil through the suction line causes oil logging at split.

04-04-2017, 08:40 PM
And especially serious capillary restrictions

04-04-2017, 08:52 PM
What make and model is your unit? ...year?

04-04-2017, 08:57 PM
Nakashi, 2007 , R 407c

Rob White
05-04-2017, 11:58 AM

I think they are confusing two separate issues.

One if a leak also leaks oil will it leak enough oil to cause a problem.
Most of the time no, normally there is always more oil than you need
and the odd little leak causes no real problem.

Two adding oil to a small split causes the capillary to block.
This is not a problem with the oil, this is a problem with the way
it was added, unless the exact same oil was added in perfect conditions
the majority of issues with adding oil is that the technician also adds
other contaminates such as air and moisture. this then blocks the capillary
and the blame is then put on the oil.

Do not add oil after a leak. it will rarely lose enough oil to cause an issue.
If you add oil after a leak make sure it is the correct oil, new and unopened
in the tin and put in under perfect conditions, with no contamination being

I will guarantee it is the technician causing the problem.



05-04-2017, 10:37 PM
very good points!
however , it is inevitably not adding air through the system when adding oil .I think that is why after that you have to evacuate the system.
when you have to add oil to a compressor ,you have to check the oil reservoir and add oil through a pump.
I do not think that anyone can guarantee that no moisture or air inserting the system.
even if you add oil at a/c split during cool operation.you open the service valve,inject the hose and start pressing oil.

06-04-2017, 02:13 PM
what is your opinion about the product in 1 photo.It can be used in an split system to add oil through cooling operation.

07-04-2017, 01:12 PM
the first costs in Greece about 50 euro

Rob White
07-04-2017, 02:57 PM

Both are fine and versions of both are found over here. :)

I don't think the problem lies with the tool but the type of oil
and the guy who put it in.



07-04-2017, 08:24 PM
Oil would have minuscule amount of water, amount would increase if it was ever exposed to air, we don't remove the moisture by heating the oil and spraying it in a vacuum chamber. This moisture would be absorbed by the dryer fitted in the system.

08-04-2017, 09:17 AM
it is impossible to add 100% pure oil through a system.some times you add a tiny amount of air during the procedure.that is why you have to evacuate the system before inserting refrigerant.

Rob White
08-04-2017, 06:16 PM

I'm a bit confused about where this conversation is going?
You started off by claiming when oil is added to an AC system
the system can fail afterwards.

We agreed and you now just keep posting ways of adding oil?

I'm confused. Adding oil to AC's is not always nessesary so don't do it.
if you do add oil then do it in the best way you can causing as little contamination
as possible.



09-04-2017, 08:18 AM
Good point Rob.
I for one will be watching this guys future posts for product placement.
Not happy with you Greek Engineer!
Those posts a close to breaking site rules!

09-04-2017, 09:13 PM
Hello !! I do not understand the attack to me...is not that forum a way to discuss about problems and issues with regard to refrigeration?
I am a little bit confused..anyway ,I do not promote any stuff and of course respect the rules...sorry in advance!!!!

09-04-2017, 09:22 PM
Moreover,I kindly thank the persons expressed their opinion about that topic.

11-04-2017, 07:26 AM
Yes I think an air condition loose a lot of oil when remove refrigerant