Gas Charging in Split Air Conditioners

Written by:  • Edited by: Lamar Stonecypher
Published Aug 21, 2009

In the previous articles we was the factors affecting the location of indoor and outdoor units of split AC, the installation of the indoor unit, the outdoor unit and the refrigerant tubing. In this article we shall see the final step of installation of split air conditioner, the gas charging.

In the previous articles we was the factors affecting the location of the indoor and outdoor units of split AC, the installation of the indoor unit, the outdoor unit and the refrigerant tubing. In this article we shall see the final step of the installation of split air conditioner, the gas charging.

If the installation of the indoor unit, outdoor unit and the refrigerant tubing is done properly, the process of gas charging in the new split air conditioner is very simple. In fact in the new split air conditioners no process like gas charging is involved. In the new units, the indoor and the outdoor units are prefilled with the gas.

When indoor unit is connected to the outdoor unit via refrigerant tubing, the tip of tubing originally attached to the indoor unit has to be opened, which leads to the leakage of refrigerant that comes with the unit prefilled from the factory. Thus this gas cannot be used in the split air conditioner for the cooling purposes.

Gas Charging from the Outdoor Unit

The outdoor unit is also prefilled with the refrigerant or the gas from the factory. Most of the gas is filled in the condenser coil at very high pressure. Since the gas is filled at high pressure sufficiently large quantity of gas can be filled in the condenser, which is good enough to produce the desired cooling effect in the room.

Since the refrigerant is already present in the air conditioning system, we don’t have charge the extra gas, however, if the distance between the indoor and the outdoor units is large, some external gas charging may be necessary. The gas present within the outdoor unit has to be released to the whole system including the refrigerant tubing and the indoor unit. Thus in the new split unit there is no actual gas charging in real sense, it is only distributing the gas compressed in the outdoor unit to the whole air conditioning system.

There are two valves located at the lower end of the outdoor unit, one for supplying the compressed gas from the outdoor unit to the indoor unit and other one for receiving the return gas from the indoor unit. Initially, both the valves are closed. During gas charging both the valves are opened slowly. With this the refrigerant gets distributed in the whole air conditioning system including the indoor unit, the outdoor unit and the refrigerant tubing.

Checking for the Gas Leakages

The gas charged into the system is like the life blood for the whole unit. Even slight leakages of the gas can hamper the performance of the system and it continuous leakage can render the unit useless. Further, even the cost of the gas is very high, so its leakage will not only lead to the breakdown of the air conditioning system, but also high costs of repairing. Hence it is vital to check right at the installation of the system that there are no leakages of the gas.

The leakages have to be mostly checked at the joints of the refrigerant tubing. There are four joints in the split air conditioner: two at the indoor unit and two at the outdoor unit, connecting the refrigerant tubing and the indoor and the outdoor units. Since the gas is now present in the air conditioning system, it is at high pressure.

To check for the leakages soap solution is applied to the joints. If there are any leakages, you will see the gas leaking in the form of the bubbles and if there are no leakages the soap solution remains stable.

If there is some gas leakage the connections have to be tightened. If the leakage doesn’t stops, the leakage point may have to be dismantled and reinstalled.

Starting the Air Conditioning System

Once the gas has been charged in the air conditioning system and it has been checked for the leakages, the system can now be started. It is assumed here that everything is goes well with the installation. When the system is started you can feel the cool air coming from the indoor unit within a minute or two.

You can adjust the position of the louvers of the indoor unit to evenly distribute the cool air inside the room or you can keep them at fix position to divert the cool air in particular direction. You can also adjust the speed of the fan. If you don’t need the cooling effect, you can keep the AC on fan mode. Most of the settings can be done from the remote control.


Comments

Showing all 25 comments
 
Collind Feb 4, 2012 4:18 PM
RE: Gas Charging in Split Air Conditioners
I have replaced a 1.5tr rotary compressor for my lg split ac, and gas charged it 60psi back pressure, but the unit runs for 10 minutes and the back pressure show vacuum on the gauge. Why its so any solution?
saad alshekhli Aug 21, 2011 8:03 AM
Environmental work Temp.
How much the maximum Environmental work Temp. that outdoor unit will still work efficically
Shek Jun 15, 2011 1:41 AM
Gas charing calculations w.r.t capillary tubes changes
capillary tube of 1.9x3.2x900; Gas charge qty. 1300gms.

What will be the gas charge qty. if we use 2.0x3.2x900 capillary tube provided the same compressor is used??
khalil May 20, 2011 5:54 AM
RE: Gas Charging in Split Air Conditioners
what should b the pressure of the gas (low side, high side) in split AC when t s charged properly.
Mohd Ghalib Jan 19, 2011 3:44 AM
Split A/C
Dear,
How many piping length 2 ton Split A/C
minimum and maximum.
Andrew Jan 11, 2011 1:59 AM
RE-gassing units
Hi i was wondering if you could post info as to process of re gassing / topping up.
abu Dec 31, 2010 9:03 AM
this is my requst
hi
i want know all compressor size how much need pressure of gas ?


Read more: http://www.brighthub.com/engineering/mechanical/articles/46340.aspx#ixzz19hMGaGml
Justin Amirtha Raj Nov 9, 2010 12:11 AM
Gas Refilling
I have LG 1.5 ton split ac, after purchasing 15 days gas leaked, the mechanic came and refill the gas up to the level of 64. My doubt is how much level of gas fill in outdoor unit?
can you please tell me the level of gas i want to fill for correct manner.

Thanks
Justin
faisal sagheer Oct 19, 2010 10:33 AM
gas charging ?
dear sir, my name is faisal sagheer.i want to ask if you dont mind how can i charge the split a/c with rotory compressor?
imran shah Aug 11, 2010 8:39 AM
gas level
hi
i want know all compressor size how much need pressure of gas ?
raj Jul 24, 2010 4:26 AM
vaccum
1.to which extend vaccum is done in split ac?

2. what is the pressure level during charging gas?
phsshiva Jul 1, 2010 11:57 AM
AC not cooling after 30-40 Minutes.
Hi, My name is Shiva. I have a split AC model AS18FJ 1.5T made by Samsung purchased in 2008. When I turn it ON, everything works normal for 30-40 minutes, but; after 30-40 min. the compressor goes to sleep mode and the Fan in the indoor unit keeps running, and this is normal I believe. However, it fails to restart compressor even when the room temperature (Measured with external Digital Thermometer) reaches 28 Degrees. And again suddenly, after 20-30 minutes, the compressor restarts again. This AC was recently recharged with 70 PSI gas, what could be the issue.
Thanks in advance,
Shiva
Shiva Jun 28, 2010 2:48 AM
Compressor Stops after 30 min.
Hi,
My name is Shiva, from Hyderabad. I have a Samsung 1.5 Split AC purchased in 2008. When it's turned ON, it works for 30-40 minutes perfectly fine with 16°C, after that, the compressor goes to sleep mode and again it does not wake-up even when the room temperature reaches to 28°C, however, suddenly after 20-30 minutes of gap, the compressor starts automatically. This AC was recently recharged with 70PSI gas. It's Samsung Bio-sleep AS12FK split 1.5T AC.
Thanks in Advance,
Shiva
raj Jun 21, 2010 3:13 PM
hi pressure
i fixed split unit and charge gas.. compressure pumping work is ok. taking amps is 14amp. but when i charge gas in section line.. pressure is 90psi but not cooling in the evaprator coil. long tim work compressure without cooling high pressure, high tempreture, then automatic off compressure.... from 60psi to 90psi not comming cool..
what i want do..... please give me answer.....
raja ravi Jun 15, 2010 12:28 AM
quantity of Gas in AC compressor
i have 1.5 ton split ac llyods make. i have to fill in gas in the compressor. the mechanic says 60 to 65 is the level of what gas is to be filled. can you please clarify how much is needed. some told me it should be about 75.... please help.
Krishna May 6, 2010 1:20 AM
Gas recharge after every shift of Home?
Hi Haresh,
I am staying in rented home, and currently thinking of installing split AC.
What do you suggest, split or window.?
Secondly, does gas recharge is required in every location shifting of split AC?
Thanks
sudhakar Apr 18, 2010 3:21 AM
RE: Gas Charging in Split Air Conditioners
nice theory, i have got the basic knowledge about split ac's thanks for the author and website for fetchhing usefull data's
Jibin.B.kurian Apr 11, 2010 10:16 PM
charging of gas
Dear sir,
I want to know that what amount of gas is needed to be filled in outdoor unit of spit AC.
DEEPAN Mar 7, 2010 1:02 PM
wishes to the work
I thank to you for giving us more information about the refrigeration and air conditioning. and what about condenser and eveporator.
joji Feb 13, 2010 8:02 AM
gas pipe length
what is the maximum pipe length can provide for conecting the indoor to out door unit of a 5 ton split air conditioner. From my flat there is more than 40 meter distance to out door unit.We are using the 5 ton york air conditioner. is this effect the system performence and is it make any problem to the compressor life?
asath ali Feb 5, 2010 5:37 AM
ac out door unit
how to charge gas to out door unit
Haresh Khemani Feb 3, 2010 12:43 PM
copper tubing
The Indian manufactured copper tubing are of the same quality as the imported ones.

There is no major disadvantage of installing outdoor unit 6 feet below indoor unit.
Haresh Khemani Feb 3, 2010 12:36 PM
Oil Trap
Hi Joji, When the compressed refrigerant leaves the compressor, it carries some oil particles. These particles can choke the capillary tube or the expansion valve thus reducing the efficiency of the refrigeration system and in some cases stop the system. The oil trap removes these oil particles and prevents them from going to the expansion device. The oil trap is a sort of metallic mesh and is usually placed after the condenser.
joji Feb 3, 2010 8:05 AM
oil trap
what is the use of oil traps in referigerent line. and how it works ?where it is using ?
thanks
anoop singh Jan 31, 2010 9:01 AM
copper tubing
(a) is indian manufactured copper tubing inferior to imported copper tubing ?
(b) any major technical disadvantage in installing the outdoor unit 6 feet below the level of the indoor unit ?
 
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