How to choose an air conditioner vacuum pump - Setafi

Need to bleed air from your air conditioner? Use a vacuum pump. Are you unfamiliar with this topic? Then read on and find out how vacuum pumps work, types of vacuum pumps, recommendations for choosing a vacuum pump.

Vacuum pump, principle of operation, design

Vacuum pumps - devices for pumping vapor / air from various kinds of closed systems. These include air conditioners and split systems. In such systems there is a circuit with a liquid. During the operation of the system, due to various circumstances, these liquids turn into steam. This vapor impairs the operation of the entire device, for example, it prevents the refrigerant in air conditioners from heating / cooling, so liquid is sucked out of the systems and air / vapor is pumped out.

Let's analyze the principle of operation and design of a vacuum pump using the example of plastic-rotary models:

There is a housing with two outlets for tubes - one of them for connecting to the refrigeration circuit, the second for removing steam from the system. An eccentric rotor with working blades is installed inside the housing. The entire internal design of the pump is completely hermetic: the rotor is hermetically connected to the housing, the spring pushes the blades apart from each other, which located between them, there is a non-return valve on the outlet tube, which releases air under pressure from the pump, but does not let it in inside. The vanes are placed to create multiple sealed sections within the pump. Such an arrangement of elements is necessary so that when air is pumped out of the air conditioner, no gases get back.

The motor rotates the rotor with blades, sealed sections are formed. One blade seems to pull air from the system, the second blocks the entrance to the system. Together they move air towards the outlet tube. When the evacuated air reaches the outlet tube, the vanes push against it, increasing the pressure. Due to the pressure, he presses on the check valve and opens it. Air is vented out of the system. Condensation forms with it. It makes no sense to delve into why it is formed. Let's just say it has to do with the difference in pressure. Then the blades return to their original position, and the cycle repeats until the vacuum is established / there is enough motor power.

Types of vacuum pumps

There are 6 types of vacuum pumps. Further, their listing with a brief description, features, advantages, disadvantages:

• Lamellar-rotary. Standard and most popular models. The principle of their work is described above. The advantages of such devices are low noise level during operation, ease of use, clear design, efficiency, price and availability. Of the minuses of the models, only that you constantly need to change consumables, mainly oil.
• Low vacuum with two pumping stages. Not as popular as the previous ones. They are distinguished by high performance due to the presence of two rotors and an increased noise level due to the same two rotors. The disadvantage of such models is the high cost of use.
• Ring-liquid(low vacuum). Another popular model They do not need oil to work, instead they consume water, and in large quantities. They also consume a lot of electricity.
• High vacuum. The main advantage of diffusion vacuum pumps is their high performance - they pump out 4-5 cubic meters of air in less than 30 minutes. Their lack of fragility - with pressure surges, they will quickly fail.
• High vacuum(cryoadsorption). These devices have high rates of efficiency, productivity, while low power consumption. Their work is based on the principle of absorption of gases with decreasing temperature. Such devices are rarely used. This is due to the fact that synthetic oils are used for their operation. Such oils remain on the elements of the refrigeration circuit, pollute the system, therefore, after using these devices, additional cleaning is required.
• High vacuum(heterionic). High performance and high performance models are rare. The main reason why they are rare is the high price.

How to choose a vacuum pump for pumping air from an air conditioner. What to look for when choosing a vacuum pump for pumping air from an air conditioner.

If you choose a vacuum pump for your own use, then first familiarize yourself with their types. Choose the right model for your situation. We recommend using a standard rotary vane vacuum pump. It is suitable for most situations where you need to pump air out of the system.

When choosing a device for an air conditioner, pay attention to:

1. Duration of continuous work. 30-40 minutes will be enough - during this time a vacuum pump of sufficient power and productivity will pump out all the air from the air conditioner route.
2. The maximum and rated power of the device. Power affects the duration of continuous operation of the equipment. A low power vacuum pump will not be able to pump all the air out of a long refrigeration circuit.
3. The length of the refrigeration circuit to be evacuated and the capacity of the pump. They must match, or the performance must be greater, otherwise the pump will also not be able to pump out all the air - it will stop at one mark. We recommend taking pumps with a capacity of 50-150 decimeters per minute. With such a capacity, the pump pumps out 4-5 cubic meters of gas from the circuit in 30-40 minutes.
4. Sealing quality.
5. Can the device be used under different conditions.