What is used to pressurize air conditioner systems to find a pin-point leaK?

To pressurize air conditioning systems for leak detection, technicians typically use nitrogen gas. Nitrogen is inert and does not react with the system components, making it safe for pressurization. By introducing nitrogen into the system and monitoring for pressure drops, technicians can identify the location of any leaks effectively. Additionally, a soap solution or electronic leak detectors may be used to visually or audibly confirm the presence of a leak once the system is pressurized.