How To Detect Air Leaks In Air Conditioner Unit?

The sad reality about detecting refrigerant leaks in the air conditioner is that they are more often detected after there has been a loss of cooling due to discomfort, spoilage, or production difficulty. Repairing the leak is not an issue but finding them is.

In this regards it is useful know that there is no foolproof leak detection method that can work for all types of leaks in the refrigerant coils. Here are some of the common leak detection methods available.

Bubble Solutions

This is the oldest known method of leak detection. In this soap solution is applied at the suspected sites of leaks on the coils. This is done with a squeeze bottle, brush or dauber. At the site of leakage the refrigerant that is oozing out will produce bubble when it come into contact with soap. However the size of the leakage should not be very small for this method to work. It may not work in windy situation.

Halide Torches

This is a more effective method than bubble solutions. In this an ignited torch is held at the probable sits of leakage. The flame from the torch will turn green when it comes into contact the refrigerants. This in on account of the chlorine atoms (CFCs and HCFCs) present in the refrigerant. However this will not be successful in all cases as all refrigerant do not contain chlorine atoms.

Electronic Detectors (Sniffers)

In this there are two methods. The first is corona-suppression detector. The process can measure the conductivity of gases passing between two electrodes. It uses an instrument to generate high-voltage spark from one point of the sensor to another point. In case there is drop in the current between these two points, the presence of an insulating gas is detected.

The other technique is called the heated diode technology. In this a ceramic element is used to heat the refrigerant to break up molecules. As this happens, the chlorine or fluorine ions of the refrigerant get positively charged. They are attracted to center collection wire that is negatively charged. The flow of these ions to the centre collection wire creates a small current. This activates an alarm that signals the presence of refrigerant.

Ultrasonic Detectors

When refrigerant leaks from a site it creates an inaudible sound. The ultrasonic detector can detect this sound and notify you about it through an alarm Advances devices can amplify the inaudible sound of a leak into a more natural sound that can be detected.

Fluorescent Leak Detection

In this fluorescent dye is mixed with a lubricant and circulated with the refrigerant throughout the system. At the sites of leakage the dye also comes out with the refrigerant. The system is scanned under an ultraviolet (UV) or blue light lamp. The dye would glow with a bright yellow-green color and pinpoint the location of the leak.

Electrolyte sensor leak detectors

In this electrolyte sensing element is used at the site of probable leakage. When it is exposed to refrigerant, an electrochemical reaction takes place that alter the electrical resistance within the element. This activates an alarm. This sensor is quite sensitive to all HFCs and HCFCs and, therefore chances of false alarms are minimal.


In this a sensor is used, which is an enhanced version of the bulk metal oxide sensors commonly used to detect a wide range of gases and vapours.

Besides this the H2 detectors are also used in certain situations. It uses 95% nitrogen and 5% hydrogen tracer gas mixture. It is able to detect leak rates of less than 5 ppm. Combustible gas detectors are also used to detect refrigerant leaks. They can detect all hydrocarbon and other combustible gases, including propane, methane, butane and industrial solvents. Nitrogen pressurisation method is also used. In this the system’s refrigerant is recovered. It is then pressurised with nitrogen at 150psi. If the system loses pressure within a course of 30 minutes, there is a leak.


Quick & Easy Estimates

Air Condition Repair Near Me - HVACR Systems

Get Service Calls