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airheatman, HVAC Technician
Category: HVAC
Satisfied Customers: 8172
Experience:  Furnace, A/C and heat pump specialist.
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Bought a 2.5 ton R22 Dry A/C Unit, I was told but cant confrim

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Bought a 2.5 ton R22 Dry A/C Unit, I was told but can't confrim that that all New Condensors are built for R 410 or some other R factor but the way they get around the R22
sales is by sneding them dry this way it can still be used for R22.

MY Question is can someone confrim this for me or better yet give me the right information.
And last but not lest do they put oil in the system already in a dry unit other than Nitrgen.

And if they don't how would I add, put oil into the compressor? and do I evacuate the system first then add oil? Or do I do it before or after?

Hello.My name is XXXXX XXXXX I will do my best to help.Troubleshooting often requires meters and test equipment.Let's get started and see what we can do! The unit is a dry unit. It has a small amount of nitrogen which you will release before pulling into a vacuum and charging. The compressor is already charged with oil.You will lose none of the oil in process of releasing the small amount of nitrogen. You will weld the unit in, release the nitrogen , pull a vacuum and then weigh in virgin R22 as per chart in unit.

Customer: replied 3 years ago.

Thanks I was not sure if the unit had a oil in it since they said dry charge.

I understand what you said about brazing first then releasing the charge and pulling a vaccum.


But their is two things I'm not to sure about. one Don't I have to take out the sharder valve seats from the compressor first before I braze or I can damage them? Second since I need to put in a new orfice size in my evaporator .71 because I have a 2.5 ton unit and a 3 ton A- Coil, is there going to be a problem once I release the nitrogen out of the system? I have to open up the old system to put in the new ofrice and install a new liquid line dryer. I'm concerned about damage to the high side and low side valves on the condensor. Or do I just leave the nitrogen in the compressor braze everything and then release and vacuum.

If you know of any other way to do this with the right tools and equipment please let me know.

Such as a core removal tool etc, etc.


Another question if I didn't have to add these extra componets, do hvac techs add nitrogen to the system then braze to prevent flaking inside and possible damage to the system.


Please answer my question in the order I presented them to you so that I may understand.

I have a very strong electrical back ground but

only a limted certification in hvac up to 2 ton units that I worked on and only when the need arises.

Thank You



1. You will first recover any refrigerant in old system if it still has freon in it.
2.You will connect gauges to new unit,open valves on new unit, release nitrogen to the atmosphere.
3. Disconnect gauges and remove valve stems with a core remover.
4.Go ahead and replace orifice in coil at this time while system is open.
5.Weld in new unit and filter drier.
6.Re install the valve stems.
7.Pull system into vacuum
8.Add refrigerant.
As for the flaking. most manufactures recommend running nitrogen through system while welding (About 3 to 5 psig. Personally I usually just weld, then before replacing valves, purge good with nitrogen .
airheatman and other HVAC Specialists are ready to help you
Customer: replied 3 years ago.

Thanks I forgot to mention that I did recover the

R22 in a recovery unit and pulled a vaccum to about 10 Hg,.. since I did that I will follow the above procedure you gave me.

You have answered all my questions and I feel confident I can continue with what I started and finnish.

Thank You


Ps. Once I add xtra $$ to my account I will add it to yours as I know you only get a portion of this fee for your services..