Aircon Gas Top Up - R22, R410A & R32 Refrigerant

Why Does Your Aircon Lose Gas?

Refrigerant gas is the lifeblood of your aircon system. It circulates between the indoor evaporator coil and the outdoor condenser, absorbing heat from your room and releasing it outside. Without sufficient gas, this heat exchange process breaks down — and your aircon blows warm or lukewarm air instead of cold.

Here is the important thing to understand: refrigerant operates in a completely sealed loop. Under normal conditions, it does not get “used up” or evaporate. If your gas level is low, it means there is a leak somewhere in the system. The leak could be at a copper piping joint, in the evaporator coil, in the condenser coil, or at a valve connection.

This is why Billy Aircon, trusted for professional aircon servicing across Singapore, always performs leak detection before topping up your gas. Adding refrigerant without fixing the leak is like pouring water into a bucket with a hole — the gas will eventually escape again, and you will be paying for another top-up in a few months.

Signs Your Aircon Needs a Gas Top Up

Not every cooling issue is caused by low gas. But here are the specific signs that point to a refrigerant problem:

Your aircon runs but does not cool the room. The fan blows air, but it feels lukewarm or room temperature. The compressor is running, but there is not enough gas to carry heat away from the evaporator coil.

Ice forms on the copper pipes. When gas pressure drops below normal, the evaporator coil temperature drops below freezing point. Moisture in the air condenses and freezes on the coil and the copper piping. You might see frost or ice on the pipe connecting the indoor and outdoor units.

The compressor runs continuously. Normally, the compressor cycles on and off as the room reaches the set temperature. With low gas, the room never reaches the target, so the compressor keeps running — wasting electricity and accelerating wear.

Your electricity bill increases unexpectedly. A system with low gas works harder to achieve less cooling. The compressor draws more power for longer periods, which shows up on your electricity bill.

If you notice these signs, a standard service may not solve the issue. The problem is not dirt — it is insufficient refrigerant.

Understanding Refrigerant Types

R22 (Freon)

R22 was the standard aircon refrigerant for decades. If your aircon was installed before 2015, it likely uses R22. However, R22 depletes the ozone layer and is being phased out worldwide under the Montreal Protocol. Production has stopped in most countries, making R22 increasingly expensive and harder to source.

Billy Aircon still carries R22 for customers with older systems. However, if your R22 unit develops a significant leak, we may recommend replacing the entire system with a modern R410A or R32 unit. The cost of repeated R22 top-ups on a leaking system quickly exceeds the cost of a new installation.

R410A

R410A is the most widely used refrigerant in Singapore today. It does not deplete the ozone layer and operates at higher pressures than R22, which means better cooling efficiency. Most split systems installed between 2010 and 2022 use R410A.

R410A gas top-ups are straightforward and competitively priced. Our technicians handle R410A top-ups daily — it is by far our most common gas service.

R32

R32 is the latest generation refrigerant, increasingly adopted by manufacturers like Daikin, Mitsubishi, and Panasonic in their newest models. R32 offers 25% better energy efficiency than R410A and has a significantly lower global warming potential.

The catch: R32 is classified as mildly flammable (A2L classification). This means handling and charging R32 requires specific training and certification. Not all aircon companies in Singapore are equipped to work with R32 safely. Billy Aircon’s technicians hold the necessary licences for R32 handling.

The Gas Top-Up Process

When our technician arrives, the first step is connecting a manifold pressure gauge to the service ports on your outdoor condenser unit. This gives us an exact reading of your system’s current gas pressure.

Normal operating pressure varies by refrigerant type and ambient temperature. For R410A, typical suction pressure is around 115-125 psi in Singapore’s climate. For R22, it is around 60-70 psi. Readings significantly below these ranges confirm low gas.

Before adding any gas, we inspect the system for leaks. Common leak points include:

• Flare joints — where copper piping connects to the indoor and outdoor units. Vibration over time can loosen these joints.
• Evaporator coil — corrosion from cleaning chemicals or acidic condensation can create pinhole leaks.
• Condenser coil — exposure to outdoor elements causes corrosion over years.
• Service valves — the Schrader valves on the condenser can deteriorate and leak slowly.

If we find a leak, we recommend repairing it before proceeding with the top-up. For small flare joint leaks, the repair is quick and inexpensive. For coil leaks, the repair may be more involved, and we will provide a clear quote before proceeding.

Once any leaks are addressed, we add the correct refrigerant type in controlled increments while monitoring both high-side and low-side pressures. Overcharging is just as harmful as undercharging — too much gas stresses the compressor and can cause liquid slugging, which leads to expensive compressor damage.

After the top-up, we test the aircon’s cooling output. A properly charged system should produce air at 8-12 degrees Celsius at the indoor unit outlet. We verify this with a thermometer and confirm the compressor is cycling normally.

When a Gas Top Up Is Not Enough

Sometimes, low refrigerant is just one symptom of a larger problem. If your aircon is not cold and the gas level checks out fine, the issue may be a dirty evaporator coil (solvable with a chemical wash), a faulty compressor, a defective PCB board, or a malfunctioning thermistor.

Our technicians assess the full picture before recommending a solution. If a gas top-up alone will not fix your problem, we will tell you upfront rather than charge for a service that will not help.

Book Same-Day Gas Top Up

Billy Aircon offers same-day gas top-up service across Singapore, subject to availability. Our technicians carry R22, R410A, and R32 refrigerant, so there is no need for a second visit. Contact us to schedule your gas top-up and get your aircon blowing cold again.