All air conditioners work by evaporating and condensing the refrigerant in its closed loop. Freon gas acts as a refrigerant, which can be of several types: modern ozone-safe R410A, chlorine-containing R22, R407c and R600a, which are rather harmful to the environment, used mainly in mobile all-in-ones and industrial refrigeration systems.
Very many malfunctions in the operation of HVAC equipment are associated with the leakage of working gas through a copper connecting pipe between the split system units or through cracks in the modules themselves. To eliminate the problem of a lack of refrigerant, it is necessary to fill the air conditioner with freon partially or completely, and ways to do it yourself will be discussed further.
Signs of a Freon leak
First of all, the master should know what are the signs of refrigerant leakage. The following features may alert the air conditioner in operation:
- no blowing with cold air;
- emergency shutdown, sometimes going into error code mode;
- freezing of the heat exchanger of the indoor unit;
- freezing of the liquid port (multi-split systems may have several of them);
- “Uneven” compressor operation;
- excessive vibration of the external module.
All these signs may indicate a shortage of working gas and require a call from the service technician.
If someone is interested in refueling a domestic air conditioner with their own hands, then you need to remember the risks of permanently ruining the equipment. To implement this is problematic in terms of the availability of working tools. Moreover, each type of refrigerant has its own characteristics, in connection with which not all charging methods are suitable in one or another case.
How to detect refrigerant leakage
Before refueling, check the device for gas leaks. This is done as follows:
- a pressure gauge is connected to the ports of the outdoor unit;
- a nitrogen cylinder is connected to it through a high pressure reducer;
- pump in 30 atm;
- check for leakage at the joints of both blocks with a special foamy liquid;
- if there are solder connections on the track, then they are also tested.
Next, we move on to the main process, which can be performed using one of the following methods.
Ways to refuel an air conditioner with freon
There are several basic methods of filling refrigeration systems with freon, applied to home air conditioners (splits), multi-splits, mobile and multi-zone systems.
DIY refueling will require the following kit:
- pressure gauge;
- Vacuum pump;
- cylinder with freon;
- construction scales;
- metalwork tools - swedish wrench, hexagons, screwdriver.
Instead of a manometer and a vacuum pump, you can purchase a manometer station.
Weighting
If you need to fill a completely empty air conditioner 22 or 410 with gas, the process proceeds as follows.
Evacuation. They wind the manometer onto the shredders and open the crane on it. Turn on the vacuum pump and stand for 10 minutes. Close the valve on the pressure gauge and turn off the pump.
Connection of a cylinder with freon. The gas container is turned upside down and put on the scales, the indicators of which are previously reset to zero values. Open the valve on the pressure gauge and pour in the required amount of refrigerant by weight.
The norm for each air conditioner and the type of gas to be injected into the compressor are indicated in the technical documentation and on the nameplate.
The crane is closed and the pressure gauge is disconnected, after which the covers on the ports are screwed. Turn on the air conditioner and check its functionality.
This method is considered the most correct, but it is complicated by the need to have expensive scales for weighing freon.
If you want to fill the 410 air conditioner with freon yourself, then first completely bleed off its residues in the manometric station for collection, and then pour in the gas by weight. This is due to the fact that this type of freon consists of a mixture of various gases with varying degrees of volatility. When one of the components leaks in a larger volume, the composition changes, and, therefore, the necessary properties of the refrigerant are lost.
If you need to fill the air conditioner with R22 freon, then they resort to such a method as filling the air conditioner by pressure.
Pressure charge
First you need to connect the pressure gauge to the gas port of the air conditioner working for cooling. The operating pressure of the device should be 3-3.5 atm. If it is below these marks, then refueling is required. To do this, connect the cylinder with freon and in small portions begin to fill it into the system by opening the taps on the manometer for 5-10 seconds.
In order not to burn your hands with gas, it is more convenient to use quick-detachable joints.
This method is convenient just when you need to refuel the air conditioner with your own hands with a small portion of R22 refrigerant. In all other cases, the simplest and most optimal method is to refuel with weights, that is, by weight.
Overheating and Subcooling
A fairly accurate method is to charge the air conditioner for overheating or overcooling. The whole point is to focus on the temperature difference.
In the case of subcooling, we have in mind the ratio of the temperature indices of liquid and condensation at the same pressure. The condensation temperature can be determined as follows: its pressure is measured with a pressure gauge, and then the data are correlated with the values of the gauge manifold scale depending on the refrigerant. To determine the overheating, compare the temperature values of the gas in the normal state and when it boils under the same pressure.
An overheating above and a subcooling below normal indicates the leakage of the refrigerant and the need to refuel it.
These methods are not suitable for refueling home air conditioners, that is, wall split systems. But they are very convenient for semi-industrial installations, as their external unit has the required fittings. In addition to instruments, an infrared thermometer is required.
A layman is unlikely to be able to refuel an air conditioner using these two methods, since they require a sufficient knowledge base in the field of air conditioning systems. Although the ease and accessibility of previous techniques for a simple layman is also a moot point.
Current conditioner refueling
Many masters do not use this method, but its use is justified in cases where it is not possible to use scales for weighing freon. So how to refuel the air conditioner yourself by current?
To determine the operating current of the compressor, special clamp meters are required, which are superimposed on the phase of the power wire of a working external unit. If the obtained values are lower than those indicated in the manual or on the nameplate, and the pipe has frozen, then refuel with freon is performed until the indicators are aligned.
All other stages completely coincide with the stages of filling the air conditioner with freon according to the weights, which can be seen on the video at the end of the article.
This method is applicable in the case of eliminating the consequences of a leak in semi-industrial equipment.
If the length of the freon path of the air conditioner exceeds the length of the line without refueling specified by the manufacturer, but does not exceed the maximum permissible value, then you need to refuel the device at the rate of 30 g (up to 3.5 kW) of gas per meter.
Freon air conditioning charge
There is no dependence of the price of refueling the air conditioner on the method used. The amount is calculated relative to the power of the device.
But how much does freon refueling cost on average? A device with a cooling capacity of 2.5 kW will require about 3,500 rubles to replenish the refrigerant in its entirety. For each subsequent standard size, 500-700 rubles are added. Thus, the price of filling with a freon DAIKIN split system with a capacity of 10 kW will cost its owner 7000-8000 rubles.
For a full understanding of the process, you can watch a video that shows how to fill the air conditioner with freon on the gauge station and weights:
