Quantum Well Infrared Photodetector (QWIP) usually suffer from a too moderate quantum efficiency and too large dark current which is often announced as crippling for low flux applications. Despite this reputation we demonstrate the ability of QWIP for the low infrared photon flux detection. We present the characterization of a state of the art 14.5 μm QWIP from Alcatel-Thales III–V Lab. We developed a predictive model of the performance of an infrared instrument for a given application. The considered scene is a cryogenic wind tunnel (ETW), where a specific Si:Ga camera is currently used. Using this simulation tool we demonstrate the QWIP ability to image a low temperature scene in this scenario. QWIP detector is able to operate at 30 K with a NETD as low as 130 mK. In comparison to the current detector, the operating temperature is 20 K higher. The use of a QWIP based camera would allow a huge simplification of the optical part.