Tfa wireless thermometer hygrometer with sensor tfa 30 3045 it p this wireless thermometer hygrometer from tfa checks room and outdoor climate while giving a recommendation to open or close the window therfore improving indoor climate p p moist room air is not good for health and can cause moisture stains and dangerous mould though neither is indoor air too dry skin mucous membranes and respiratory tract burdened by the dry air also has a negative impact on pets plants wood floors