Coolers lose gas due to leaks. These leaks must be found and sealed prior to any recharge. Recharge is with a set charge of gas as well as a set charge of lubricant into a non leaking system with zero air. It can be complex for a non tech person to do this.

The type gas used and the weight amount used will depend on system size and temperature of operation. To scavenge the air and water they often draw a vaccum and purge a few times with a small amount of gas. In addition a drier capsule is inserted in the circulating line.

Respected Sir,

You are right whatever you have written,it may be difficult for the non tech. person.but my main concern is only how can we recharge the walk in chillers & frezzers of different capacity with types of gases in proper amount.I have the temp.& pressure chart if recharge the gas according to that never goes right.Is that chart for any capacity of chiller & frezzer.Even if you want to have a look i can mail to you for your refrence.Is there an good idea to come to know gas has been recharged in proper amount in HVAC equipment.I know each & every thing about chillers & freezers but when ever i recharge the gas,always recharged gas in either in less or more amount.thanks & regards manish

You should be able to get basic specs from the manufacturer that will differ slightly with each install due to application, size and location. Are you sure that it was installed correctly........ matched sizes and proper metering device? Also chillers and freezers obviously operate at different temperatures so they will also operate at different pressures and the sight glass is for reference only in my book because too many variables effect their accuracy for charging a unit. When you charge it you need to let it stabilize before you start venting or juicing it. Are you putting room temperature product in it? If so you have to factor that into your readings. How hot and/or humid is it in the cooler? How hot is it outside at your condenser? Are you sure your using R-22 on a freezer? Many factors..........Call a professional and ask him many questions while he repairs it so you can have better luck next time.

Respected Sir,

You are right,you should be able to get basic specs.My main concern is only how to fill the gas in chillers & frezzers of different capacity in proper amount.When ever i recharge the gas by seeing the sight glass always fill either less or more.I have temp. & pressure chart too but useless because never goes right according to that.Even if you wanna i can mail to you for your refrence.But if you can advise on the above i woulg be thankful, thanks & regards manish

Charging a system by sight glass is not always good way because if you have non condensibles you will never clear up the sight glass and end up overcharging the system a better method is to charge a unit to a 10 to 15 *F sub cooling

Respected Sir,

I did not under your below mentioned point

1. Better method is to charge a unit to a 10 to 15 *F sub cooling.Please could you expain me this in bit detail because i can recharge each equipment but never get an idea whether its recharged in proper amount or not.Please its my humble request to you.Is this method apply even for small chiller like undercounters,doubledoor etc.thanks & regards Manish