Lost oil from condenser venting?

[CarlosJr]

During the installation of a 2.5 ton R-410a multisplit unit, approximately 7 pounds of refrigerant were inadvertently vented outdoors due to a DIY installation mistake. The location where the cut happened did have visible PVE oil residue. The entire yard was filled with mist for about 20 minutes (and I'm wondering if some of that was oil too). The system was idle at the time of the venting and the compressor had not been running previously.

After fixing the leak and recharging, the unit worked normally. However, I am concerned that it may have lost oil and that may shorten the unit's lifespan. What are my options?

Also, how toxic is the oil mist?

 

[fitter30]

Here's the data sheets. I personally wouldn't worry about it. It would be a guess how much oil you would of lost. Was there oil dripping around where the line was cut. Few drops looks like a lot. Which line was cut? Poe oil is expensive manufacture tech would have tell you the type of poe oil could be RL 32 or 46.

https://www.google.com/url?q=https://www.comstarproducts.com/pub/media/wysiwyg/pdfs/SDS%2520ComStar%2520Polyol%2520Ester%2520Oil%252032%2520(POE)%2520150%2520SUS%252045-008,%25205%2520gallon.pdf&sa=U&ved=2ahUKEwjMi5-N5tiOAxWxjIkEHevyKc4QFnoECAQQAg&usg=AOvVaw0nSqhz64v6-e43ld4yZ8Md

 

[CarlosJr]

It's FV50S PVE oil, so the MSDS is https://www.nu-calgon.com/media/8953/4319-20_sds_eng_20221207.pdf

No symptoms. But the mist was everywhere. Saw it in my yard and crawlspace cams. I'd like to better understand whether the mist was just refrigerant and water vapor, or if there was a lot of oil mixed into it. It did last surprisingly long and I had to air out the garage. There was a bit of an odor to it, but not strong.

Cut was liquid line near the condenser. Nothing dripping from the line; the oil was only seen on an object in the direct path of the discharge.

 

[chinboys]

The refrigerant oil is need for the lubrication of the compressor, its pistons or scroll. And it is carried throughout the system by the refrigerant in a mist.
You will need to add the replacement amount equal to what was lost via a refrigerant oil injector.
That is the 69K question.
The right way would to recover the all of the refrigerant and to extract as much of the remaining oil from the system's low and high side as well as any oil in the system's accumulator (tank on the low side right before the compressor) or the receiver (tank on the high side after the compressor).
The manufacturer of your system ought to be able to tell you the number of fluid ounces required.

 

[CarlosJr]

The refrigerant oil is need for the lubrication of the compressor, its pistons or scroll. And it is carried throughout the system by the refrigerant in a mist.

So, the lingering mist in the air after venting was mostly oil? Suffocation aside, have people actually been harmed by it?

You will need to add the replacement amount equal to what was lost via a refrigerant oil injector.
That is the 69K question.
The right way would to recover the all of the refrigerant and to extract as much of the remaining oil from the system's low and high side as well as any oil in the system's accumulator (tank on the low side right before the compressor) or the receiver (tank on the high side after the compressor).

How is this normally done? I wasn't able to find any instructions for a minisplit that did not involve invasive disassembly procedures. Seems like it's a common maintenance task on automotive A/C, but pretty much unheard of on minisplits.

The manufacturer of your system ought to be able to tell you the number of fluid ounces required.

Spec sheet says 23.7oz of FV50S.

 

[danski0224]

The only way to check oil level on a hermetic compressor that doesn't have a sight glass is to remove the compressor and then drain the oil into something and measure it.

 

[CarlosJr]

The only way to check oil level on a hermetic compressor that doesn't have a sight glass is to remove the compressor and then drain the oil into something and measure it.

So that would involve recovering the refrigerant, opening the condenser unit, cutting/de-brazing the internal connections, and voiding the warranty. Right?

What would a professional HVAC tech do in this situation?

 

[danski0224]

So that would involve recovering the refrigerant, opening the condenser unit, cutting/de-brazing the internal connections, and voiding the warranty. Right?

Pretty much.

What would a professional HVAC tech do in this situation?

There's no way to know how much oil was pulled out of the system by the rapid release of refrigerant. Most of the oil should stay in the compressor during normal operation.

I doubt there is any refrigerant left in the system to recover.

If something like this happened on a job with a paying customer, the right thing to do would be to replace the unit... but you can probably guess what the likely outcome is of that scenario.

Or, one does nothing, and hopes for the best.

Or, add 1/2 of the total oil capacity, and hope for the best.

A bigger concern is air/humidity contaminating the remaining oil and the filter drier because the system is open. A vacuum pump won't pull moisture out of the oil.

 

[danski0224]

Seems like it's a common maintenance task on automotive A/C,

The reclaim machines used in automotive AC service are made to separate the oil from the refrigerant and it gets collected to be measured. At least that's how it worked last time I used one.

There's filters and driers so the refrigerant can be re-used.

A typical portable recovery machine used for residential or commercial HVAC service just pulls out the refrigerant and puts it into a recovery cylinder.

A machine made for mobile AC service (like cars) isn't really portable.

I'm sure that there's refrigerant reclamation machines for commercial work, but I've not used one yet.

 

[CarlosJr]

I doubt there is any refrigerant left in the system to recover.

The line was fixed, the system was recharged, and it's running fine now. "fine"

It would be unfortunate if it only lasted a 1-2 summers due to low oil. Also unfortunate if I overfilled the oil tomorrow and that wrecked it.

Not sure which course of action is least risky but I'm leaning toward "do nothing"

So was the long-lasting fog a result of oil release?

 

[danski0224]

So was the long-lasting fog a result of oil release?

No clue.

 

[danski0224]

Not sure which course of action is least risky but I'm leaning toward "do nothing"

Unfortunately, there's only one path that leads to the correct answer.

Anything else is just a guess.

 

[CarlosJr]

The reclaim machines used in automotive AC service are made to separate the oil from the refrigerant and it gets collected to be measured. At least that's how it worked last time I used one.

There's filters and driers so the refrigerant can be re-used.

A typical portable recovery machine used for residential or commercial HVAC service just pulls out the refrigerant and puts it into a recovery cylinder.

A machine made for mobile AC service (like cars) isn't really portable.

I'm sure that there's refrigerant reclamation machines for commercial work, but I've not used one yet.

I do have a portable recovery machine and a shiny new Vevor cylinder. There is a filter-drier but no oil separator. I think this means I need to run it on slow mode and extract the gas only. Haven't had occasion to use it yet.

I'm assuming that if I had an oil separator attached to this setup, it wouldn't be able to extract all of the oil from a minisplit, right?

 

[danski0224]

I'm assuming that if I had an oil separator attached to this setup, it wouldn't be able to extract all of the oil from a minisplit, right?

It's only going to extract the oil that's mixed in with the refrigerant.

Could be quite a bit if the system is on and you pull liquid out.

Or very little if it's off.

Just guessing. But it won't get all of the oil out.