Top up variants
The statistics asserts that any climatic class product during exploitation loses 8% from the initial charging for a year, therefore it is necessary to charge the split-system with freon once in 2 years. And will you do it yourself or will you invite a specialist. it is a separate question. The air conditioner needs to be charged and if it produces a slightly lower temperature than you set on the display, the pressure must be constant inside the system and the amount of refrigerant plays a major role in this.
Very important! Lack of refrigerant volume does not ensure normal operation of the unit, and excessive pressure is a sure cause of unexpected compressor failure.
There are two basic methods of charging the air conditioner with freon.
- By pressure. In order to define the quantity of volatile gas for charging it is necessary to know the optimal pressure, mentioned in operation manual, compare it with the pressure in air conditioning system, which is shown by connected manifold. As a rule this method of charging air conditioner according to pressure is realized at freon leakage because of long exploitation.
- By weight. The method is applied at full refrigerant replacement. firstly it is pumped out of the system, and then with the help of electronic scales, knowing the weight of gas, pumped into the cylinder, the split-system is charged with freon.
There is a method with the help of measuring glass, but they are used for charging of air conditioner with the refrigerant very seldom, only after realized repair. If air bubbles are detected in the special sight-glass, no freon will be pumped until they are eliminated from the system.
Instructions how to charge a conditioner with freon
Good day to you all! Today in this article we are going to talk about charging of split-system. During its operation or just after the low-quality installation one can discover the lack of coolant (freon) in the system. If the cause of the leak is a factory defect (a leaky radiator of the internal or external unit), it usually manifests itself during the installation of the unit. If a factory-made defect is not detected, then there are only two main reasons of leakage:
- The first reason is a mistake of installation (approximately 80% of cases of leakage). Most often it is connected with low-quality rolling of copper tubes. If this is the case, the cause of the leak must be found and repaired before the air conditioner can be recharged;
- The second reason is a natural leakage (if it is possible to say so). Though, according to theory, freon circuit should be tight. Even with expensive models, minor refrigerant leakage through connections and service valves cannot be ruled out.
The process of charging an air conditioner with refrigerant is not long, but requires care, caution and understanding of the entire process. The slightest mistake when pumping freon can cause serious damage of split-system. And you can suffer yourself. So I STRONGLY DO NOT HELP THAT OPERATION BY YoursELF WITHOUT AN EXPERIMENTAL CONDITIONER’S TRAINING KNOWLEDGE.
Freon for charging the air conditioner
As well as refrigerators, conditioners are charged with freon, but freon in a conditioner is used special, intended only for this kind of equipment. Typically the types of grades used are.
Most often 3 kinds of freon are used for charging an air conditioner:
Weighing in the Correct Amount of Refrigerant in a Mitsubishi Mini Split Unit!
- R-22 is a reliable refrigerant with high coefficient of efficiency of cooling which distinguishes it among other types. When using this type of substance the power consumption increases, but the air conditioner starts working and cooling the room faster. Its substitute, R407c, is also suitable. This type of refrigerant contains chlorine.
- R-134 a. a new type of Freon, which does not harm the environment, does not contain impurities and also is characterized by high efficiency of cooling. However its cost is high, that is why this refrigerant is rarely used. This type of Freon is often used for vehicle refueling.
- R-410A. ozone friendly freon.
- Filling by weight. In this case it is necessary to weigh a container with freon and to calculate a necessary quantity which should be in a system for normal work of the conditioner. But for this purpose it is necessary to use special scales, as well as to carry out vacuumization inside the equipment.
- Charging by pressure. For this purpose it is necessary to have a pressure gauge manifold. In this case it is necessary to know technical specifics that are indicated in equipment certificate, and freon is introduced in small portions in order to control the process of equipment filling.
There is another way. charging through temperature difference, but it can be done only by professionals.
After installing the equipment manufacturers usually charge the unit based on the standard length of the pumping line, the amount of refrigerant needed is usually specified in the technical documentation of each air conditioner. Plate with data can be usually found on the case of external unit or on a protective cover of air conditioner.
It is not necessary to calculate the exact amount of freon, it is enough to know the approximate value. For example the average length of the route is from 3 to 5 m, and when charging the equipment with the power up to 2 kW it will be necessary to use about 90 g of the refrigerant. If the device power is 8-10 kilowatt, you need about 600 g of freon.
If the pumping line is longer then 15 g of the refrigerant should be added for each meter of its length.
Volume of refrigerant (Freon) in air conditioner
On a question, how much freon is in air conditioner (volume of refrigerant), there are two answers.
- The system has been installed for a long time, and the user is interested in the volume of freon in the air conditioner, and whether the quantity of the refrigerant is enough for the good operation of the product. It is almost impossible to check exact freon volume in split-system with the help of specialists or independently, but it is possible to know about freon pressure in a conditioner, all working parameters in order to find out if it is needed to top-up it with the help of special equipment and service master.
- Split-system is installed with prolonged routing of communications or it is needed to recharge it completely. What quantity of the refrigerant is required for normal operation in this case? In order to calculate independently the amount of gas, which should be in the air conditioner, you need specific information. you can find it in the table.
There are labels on remote and internal blocks, where freon brand, its quantity in kg and working pressure are pointed.
Standard quantity of the refrigerant depends on the conditional capacity of the article: “seven” has up to 750 grams, and in the most powerful split-system up to 1,7 kg. If your line is longer than the manufacturer recommends, you have to add 15 to 30 grams of the coolant for every extra meter. Each brand of product, for example LG or Toshiba, has its own limitations on the height between units and the length of the route. It is inadmissible to exceed them. к. it affects the performance of the whole system.
Causes of Freon leakage in a conditioner
For the proper functioning of the product the freon amount in an air-conditioner should be sufficient for constant circulation; unfortunately during the operation the leakage still takes place and the following reasons can be the reason of it.
- Imperfection of the construction. copper pipes that the freon goes through are rolled out in place during the installation, that is why in the process of exploitation the insignificant losses happen. It is necessary to charge the conditioner with freon with the lapse of time.
- During the transportation of previously installed product freon in air conditioner can a little bit reduce in volume, the same nuances can happen during the dismantling and re-installation. Therefore, it is necessary to pump freon into the air conditioner at the new installation site.
When the product is regularly serviced, timely cleaned, there is no excessive evaporation of the refrigerant, the only negative thing is its leakage through the connections.
Many users are sure that it is impossible to top up the air conditioner with your own hands, but such very doubtful rumors are supported by the service specialists, in order not to lose their earnings. Yes, you will need specific equipment, but it is not a problem in our progressive century.
Freon quantity control methods
Finding out how to charge the split system with freon by yourself it is necessary to remember that amount of the refrigerant should be sufficient but not excessive, hence it is necessary to observe the freon amount. If there is too much gas in the circuit, the operation of the unit will be seriously compromised because the refrigerant will simply not have time to evaporate. It can seriously damage the compressor.
Such situation is worse for the unit than if there are a few grams of refrigerant missing in the system. Therefore, during charging, it is necessary to organize control of the quantity of freon entering the system.
- by measuring the change in mass of the cylinder with the refrigerant;
- Considering the pressure in the system that must reach a certain value;
- by evaluating the condition of the circuit through the sight glass;
- considering the variation of temperature of the fan of the indoor unit.
The easiest way to control the amount of freon is to record the change in weight of the cylinder. For this purpose before charging they put a container with the refrigerant on the scales, zero the result and observe the change of indicators while the stopcock of the cylinder is open.
As soon as its weight decreases by the necessary value, filling is stopped at once. Of course, this method is only used for complete filling of the circuit. if it is needed to simply top up the system, it is needed to know beforehand the weight of the refrigerant that is already inside, and it is difficult to do it at home.
There are professional scales designed for this purpose, but many masters make do with inexpensive household models.
The device must meet the following requirements:
It is more convenient to use electronic scales, which are easier to use to track changes in weight of a bottle with refrigerant.
Another available option is to bring the pressure inside the circuit up to the necessary value. In order to do this, you will need a pressure gauge manifold. Using this device, the pressure inside the system is evaluated.
The refrigerant is fed to the circuit in small portions, constantly checking the pressure information against the standard value until a match is reached.
Before charging the system with refrigerant, find out why the system is leaking and repair the problem. Re-check after work is completed
Manifold is rather expensive equipment, which does not make sense to buy to use once in several years. It is useful not only at the stage of pumping freon, but also at dehydration and vacuumization of the system. You can borrow such a device from a craftsman you know or rent one from a specialized shop.
The sight glass method is available for professionals. It consists of observing the state of the refrigerant flow, tracking the moment when the air bubbles disappear from it. In home conditions, the first two methods are often used.
Measuring the temperature is simple, but not very reliable. At the fan when the circuit is filled, the temperature should usually be about eight degrees, although there are models for which this figure is five, a deviation of a couple of degrees is allowed. The refrigerant is introduced in small portions, periodically making measurements.
A classical line for an air conditioner
At installation of split-systems there is such a notion. “installation set”. It is a set of materials, including consumables, components, tools and fixtures, which are used to assemble individual air conditioner units into a single whole.
None of this kit is included as standard with the split system and must be purchased by the user at an additional cost. Quantity of materials depends on place and conditions of installation, that is why the route of air conditioner can differ in cost, but its principle is the same for all split-systems.
The following materials are required for routing the cooling circuit:
- Copper tubes with diameter of 1/4 and 3/8 inches for laying the route. refrigerant supply and return;
- Brass nuts of the same diameter connecting the tubes to the split system units;
- 6×6 and 6×10 mm insulating sleeve to cover copper tubes to prevent loss of energy to the coolant;
- Sealants for processing joints of the air conditioner;
- Pipe benders and pipe cutters;
- Rolling machines or fixtures;
- Tools for drilling and drilling into walls of any kind of material (perforators, cutters, etc.).п.).
Copper tubes account for the bulk of the cost of the installation kit materials. For ozone friendly freons such as R-410A one needs pipes with thicker walls as these refrigerants work under high pressure of 26 atmospheres, as opposed to R-22 with pressure up to 16 atmospheres.
For this reason the cost of copper tubes, and hence of air conditioner’s line is greater. All other materials for the route, taken together, are several times cheaper.
At installation of a line for pumping air conditioner professional tools and devices are required to provide the necessary quality of work.
Factory charge of split-system is designed for 5-7 m length of freon pumping line, but less than 3 m.Even if outdoor and indoor units of a split system will be closer to each other, the length of the pipes can not be less than 3 meters. This is necessary for proper operation of the compressor. In such cases surplus of copper tubes is rolled up into ring and placed near blocks of split-system. If the length of a line is more than 7 meters, the conditioner needs to be topped up with freon at the rate of approximately 16 grams of the refrigerant for each “superfluous” meter of a contour.
While laying the route of conditioner as much as possible one should avoid the height differences and complicated bends because this has an unfavorable influence on efficiency of split-system’s work, i.e. it reduces the efficiency, increases the compressor load that results in reduction of working resource. Thus, the classical route of pumping freon has a length of 3 to 7 meters and the simplest configuration.
In order to fill up independently and without prejudice to the unit, you should follow certain rules.
- One of the simplest and the safest way of refueling is weight method. All the necessary information is indicated on the plate on the unit. New outer blocks do not need refill, if the length of pipelines is not more than specified by the manufacturer.
- It is necessary to charge only 10% of total mass of refrigerant in split-systems that have been operating for a long time and have been dismantled. This information is again indicated on the nameplate.
- Sometimes the amount of refrigerant in the unit can be low if the piping is not properly installed or connected. And to correct the situation, you need to release all the freon in the unit to the outside, trying to keep the oil inside the compressor. For this purpose open a valve through which the charge is made a little. In a few hours all the Freon will be out of the system. If oil starts to flow out with the gas, it is necessary to open the valve even less. When the refrigerant is drained out it can be recharged with the new CFC.
Nowadays there are several types of freon or refrigerant. In the system, this gaseous substance is not only a working element of air conditioning, but also a kind of lubricant for the compressor, which is in any installation.
Any split unit consists of two blocks. One is always installed outside the room and the other is always installed inside the room. From one compartment to the other goes the refrigerant pipeline, through which the freon circulates, as well as the electric cable and draining system. For wiring the freon line, only tubes of small cross section in diameter, made of copper are used.
Freon amount in split system directly depends on the length of the pipe line for that gaseous substance, as well as on the capacity of the compressor. For example, the standard line for the air conditioner is up to 5 meters long. If even you buy a new system, then if you increase the length of freon pipe, you will have to do refill it in the system itself. That’s why there is no unambiguous value for all systems that can be used as a guide when topping up or completely charging them.
Directly at the manufacturer’s plant, the unit itself is usually primed for the available length of the route. It is worth noting that in air-conditioning systems, the length of copper pipelines is less than 3 meters.
Thus it turns out that for each meter of copper line one refills in the system 0,15 kg of the refrigerant. Plus this mass is added to the power indicator of the built-in compressor. If to take parameters in general ratio it turns out that powerful installation has in itself about 0.5 kg of freon.
Of course over the course of time in each installation there is a gradual evaporation of freon. This process speeds up if during the installation of the system mistakes were made and the pipeline joints, or rather their connection was made poorly, and the gas evaporated little by little through the gaps left. Of course in these cases all the faults in the system should be solved before a new filling or refueling.
Galvanic steam and pitting corrosion
Now some words about processes that take place in metals. When some metals come into contact with each other, microcurrents begin to flow in the place of their connection, which cause corrosive processes in a less “aggressive” metal, up to its complete destruction. When copper interacts with steel, the first metal oxidizes and the second one corrodes.
Imagine the situation when a crimp nut (fitting) made of unalloyed steel is attached to a copper pipe in a freon line. Over time the junction point becomes oxidized, resulting in the gradual destruction of steel and breaks the integrity of the oxide film that protects copper from atmospheric influences. Result: Oxidation, corrosion and depressurization of the circuit.
The table shows the galvanic compatibility of the metals. The sign “” marks the materials that do not create galvanic couples:
Situation two: use of incorrect solder and flux for brazing the cooling circuit of the air-conditioning equipment. In fact, the proportion of such errors is 15-20% of the total causes of corrosion. The wrong solder can create galvanic couple mentioned above, and the flux residuals in pipes after soldering inevitably leads to pitting corrosion, which is characterized by rapid flowing and leads to the peo-formation of the pipe section.
The solution of the problem of installation and repair of a refrigeration contour of air-conditioners is seen in the use of proper materials, as well as in the precise observance of the rules of connection and soldering of the copper pipe. Besides, in order to prevent oxidation of copper pipes and depressurization of the contour one can “reconcile” the metals that are not very “friendly” with each other by tinning of the most “aggressive” copper.
How much freon is and how much should be in the air conditioner
At operation of any air conditioner there is a gradual. and in the presence of a malfunction and accelerated leakage of the refrigerant, which means that inevitably there comes a time when this device must be topped up, or even completely refilled. In this case it is necessary to define the volume of recharge, and for this you should know two things: how much freon is in system of air-conditioner and how much freon is in air-conditioner at the given moment.
How much freon is there in a conditioner??
Standard split-system is two modules: outside and inside. Between them there is laid a freon line from copper pipes filled with the refrigerant. Freon volume in air-conditioner depends on compressor capacity and length of a refrigerating line, that is why not any expert can give the exact figure.
In a factory conditions the equipment is charged with the refrigerant on the basis of 3 to 5 meters length, that is why the line should be laid not less than 3 meters, if it is longer than 5, one should charge the unit with more refrigerant. On the average about 15 grams of freon are necessary per one meter of line. The manufacturer lets you know how much freon is in the air conditioner by means of an information table on the cabinet. In the weakest models it can be 90 grams, in powerful split-systems it can be up to 600 grams.
The amount of freon in the air conditioner can decrease as the refrigerant evaporates through the leaky fixings of the line. The line is filled only after assembly and evacuation of the system. This procedure is performed by specialists as it requires special skills and equipment.
Freon volume in window type air conditioners is constant. The line is filled with the refrigerant at the factory and there it is hermetically sealed. Refilling is necessary only after compressor repair.