A refrigerant detection assembly for detecting moderate-to-low GWP value refrigerants, an air conditioning system for incorporating the same, and a method of detecting refrigerant leaks using the refrigerant detection assembly are provided. The refrigerant detection assembly may be disposed proximate to an indoor heat exchanger. The refrigerant detection assembly includes a nondispersive infrared (NDIR) sensor, a fan disposed adjacent to the nondispersive infrared sensor, the fan configured to direct a sample to the nondispersive infrared sensor, and a controller operatively connected to the nondispersive infrared sensor and the fan. The controller is configured to operate the fan in constant operation and trigger a response when the refrigerant detection assembly detects at least 25% lower flammability limit (LWL) in the sample.