... .3) Environmental ,Ventilation, Health - Use natural water cooling .4) Waranty 2 years for complete unit ,3yeats ... Fan,Purifier and Humidifier.2. Honeycomb wed pad for optimum performance,which provides the largest contact ... the fresh air as an input and using cooling pad as an air cooler and filtering, therefore ... . It means there are Air Changing, Air Cooling and Oxygen (O2) increasing at the same time ...