Normal aircon gas pressure is 115 to 140 psi on the lower side for R32 refrigerant. The higher side or discharge side has much more gas pressure. The pressure is different for different refrigerants. Maintaining the gas pressure is important for the air conditioner to keep it running efficiently. The refrigerant level of the aircon can drop over time, leading to a performance drop. Knowing the AC gas pressure on the high and low sides is essential for topping them up on time.
Aircon Gas Pressure Chart
Below is the normal AC refrigerant pressure for different types of gases:
| Gas Type | AC Type | AC Capacity (Ton) | Suction Pressure (PSI) | Discharge Pressure (PSI) |
| R22 | Window AC | 1 – 1.5 | 60 – 70 | 250 – 300 |
| R22 | Split AC | 1 – 1.5 | 60 – 70 | 250 – 300 |
| R22 | Commercial AC | 5 – 10 | 65 – 75 | 250 – 300 |
| R410A | Window AC | 1 – 1.5 | 110 – 130 | 400 – 450 |
| R410A | Split AC | 1 – 1.5 | 110 – 130 | 400 – 450 |
| R410A | Inverter Split AC | 2 – 2.5 | 115 – 130 | 400 – 450 |
| R410A | Commercial AC | 5 – 20 | 120 – 140 | 410 – 470 |
| R32 | Split AC | 1 – 1.5 | 115 – 125 | 380 – 420 |
| R32 | Inverter Split AC | 2 – 2.5 | 120 – 135 | 400 – 450 |
| R32 | Commercial AC | 5 – 20 | 125 – 140 | 400 – 470 |
Succession Pressure Vs. Discharge Pressure
To know the aircon gas pressure correctly, you must know the suction and discharge pressure.
Suction pressure is the pressure on the low side of the system. This is usually measured at the evaporator end. This pressure will tell you about the ability of the aircon to absorb heat from the indoor. Low suction pressure is an indication of low refrigerant levels.
Discharge pressure, or the high side pressure, is the pressure of the aircon gas in the condenser. The compressor discharges the gas in the condenser unit with high gas pressure. This pressure is necessary for effective cooling. Abnormal discharge pressure is also not desirable. It can indicate blockage, compressor failure, or low refrigerant level.
During regular maintenance, the technician should measure both gas pressure types to ensure the aircon is running smoothly.
When to Refill Based on Refrigerant Type and Pressure
For R410A systems:
Refill when suction pressure drops below 110 PSI or discharge pressure below 400 PSI.
For R32 systems:
Refill when suction pressure drops below 115 PSI or discharge pressure below 380 PSI.
For R22 systems:
Refill when suction pressure drops below 60 PSI or discharge pressure below 250 PSI.
Additional Considerations
Regular maintenance: You do not ideally need to refill refrigerant frequently. A refill is necessary only if there’s a leak. Therefore, regular aircon maintenance is necessary to avoid major problems.
Leak detection: If your gas level is low, there might be a leakage issue. It is essential to repair the leak before gas filling. Otherwise, the gas will escape, and you must refill consistently.
FAQ
What happens if my AC refrigerant is low?
If your aircon gas level is low, it may result in low AC performance. The cooling will drastically decrease, and energy consumption will increase.
How often should I refill AC gas?
There is no regular aircon gas refilling schedule. You only need gas refilling when there is a leakage. There are many reasons for aircon leakage. To avoid this, maintain the aircon regularly.
What is the difference between suction pressure and discharge pressure?
Suction pressure is the low-side pressure in the system, measured at the evaporator coil, while discharge pressure is the high-side pressure, measured at the condenser. Both indicate the refrigerant’s ability to absorb and release heat.
What refrigerant is best for air conditioners?
R32 is the most advanced aircon refrigerant that is used in almost all modern air conditioning systems. R410A is also a good one. Due to energy efficiency and environmental concerns, R22 gas will be phased out recently.
Can I refill my AC gas myself?
DIY aircon gas refilling is not recommended. It can harm your health and the air conditioning unit as well. You need advanced tools that will cost you more than doing this job with professionals.
How do I know if my AC needs a refill?
Poor aircon performance, warm air, higher energy consumption, and decreased airflow indicate low gas levels. In these conditions, you need to check the gas pressure and determine whether there’s a leakage problem.
What causes a drop in AC refrigerant levels?
Leakage is the major reason for the aircon gas level going down. Over time, aircon connections and the coils can wear down, which may cause the refrigerant to escape. Maintain aircon regularly to prevent these issues.
