• If the humidity level is 35 % RH or below, the garage air is usually too dry for leather and plastics. This can result in brittle leather, porous seals and cable breaks. Therefore, the pointer is located in the red range in this case. 
• To prevent rust and corrosion from covertly beginning their destructive work and mould growth from going unnoticed behind the dashboard and inside the seats the humidity level should maximally range between 45 and 50 % RH – the green range. 
• At a relative humidity of only about 55 % RH metal begins to corrode, and moisture accumulations can no longer dry out properly. At 70 % RH and above, mould finds an ideal breeding ground after only a few hours – this is why these precarious ranges are also highlighted in red on the colour scale of the BZ15C.

... or keeps moving in the critical range. Then it is definitely time to take appropriate countermeasures such as increased heating and/or ventilation until the two pointers of the BZ15C have returned to "greener pastures". The optimum climate control for your classic car garage can be achieved by relying on professional dehumidifiers from Trotec such as the renowned devices of the DH-VPR+ series with intelligent ThinC! climate technology.