How noisy is an illuminator?
It is very noisy, slightly so or completely silent, depending upon the power source and the construction. There heat dissipation is something which has to be done by one of two means: ventilation or radiation. If radiation is the way chosen then the housing should have the mass and surface to make sure dissipation of the heat. Within ventilated systems, the air is the agent for cooling and should be evacuated and renewed. The problem is as some light sources are so hot which would require an oversized housing to dissipate all the heat build up, evidently not a very practical solution.
Silent illuminators use usually gas discharge lamps or small halogen, devoid of mechanical ventilation and relying upon radiation to cool the housing and dissipate the heat. Usually, works well only when placed outdoors or in a volume where the ambiance temperature is significant lower than that of the housing.
Forced air drought is utilized in most power illuminators and the noise can range 20 or therefore dB to 70 or 80dB. Taking in account that noise in a forced air system is concerned to duct size and air speed, as well to ventilator speed, vibration, mounting and other related aspects is simple to suspect which design can vary the amount of noise as a illuminator produces. It can be brought down to a minimum that can only be further decreased by damping with noise suppression material.