Tongdy Control Technology Co. Ltd Founded in 1999, Tongdy Control Technology Co. Ltd specializes in designing and manufacturing HVAC digital thermostats which can monitor and control temperature, humidity and IAQ. We also provide hygrostats, CO2, CO and other gas detectors, monitors and controllers. 20 New Products per Year Our R&D team can provide more than 20 new products each year and custom products according to your requirements. As an ISO 9001:2000-certified manufacturer, all our products carry CE approval. Delivery within Three Weeks Our minimum order is 50 units. To place an order available within three weeks, call us directly or contact our agencies in the UK, Denmark, Sweden, Holland and Canada.