Greetings everyone,

I have a newly made refrigerating room which is intended to keep the room temperature between 3 and 5 degrees C.
I have a compressor unit UNT 6222GK, Evaporating unit ECO EVS181 ED with 3 fans and an expansion valve Danfoss TES2 for R404a.
The problem is that the room doesnt go bellow 8 degrees C. The room has a triangle shape with dimensions 3/3/2 and a height of 2.5 meters.
The things is that i really dont know what to do to it or what may be the cause. The evaporating unit with fans off reaches -15 degrees in about 3-5minutes but when the fans turn on, even when the room is around 10 degrees, the evaporator get to +10 degrees C in a matter of seconds. Its like its efficiency is too low. The back pressure its 3 Bars.
Can it be the expansion valve faulty? or the refrigerating agent bad? Or condensation temperature too low?

Thanks in advance for any information!