Shanghai Thenow Purification Technology Co., Ltd is professional manufacturer of heat recovery ventilator and energy reovery ventilator systems. We are located in Shanghai China. with advanced production machinery, state-of-the-art laboratories and excellent R& D team, Thenow always bring out better and better products. The heat recovery core, energy recovery core and filters inside are all made by ourselfs. You can always expect good quality and good price from us.