Wireless sensor network (WSN) has been introduced for Heating, Ventilating and Air-conditioning (HVAC) systems since early 2000s. It has attracted much attention from academia and industry because wireless-based system can offer building owners and facility managers more choices and fewer constraints in installation, operation and maintenance of HVAC systems. Test-beds have been constructed in universities and research institutes, initial testing results have been reported, and several companies begin to provide WSN solution for commercial buildings. People realize that WSN will bring opportunities for upgrading HVAC systems and improve services in the near future. This paper provides a survey of the research and development of WSN for HVAC applications in the recent years. The paper will focus on the state-of-the-art techniques of WSN for HVAC applications, including the topology of WSNs, WSN-based monitoring, control and management, and the associated building energy saving potentials. The survey concludes that R&D of WSN for HVAC applications is still in the rudimentary stage, and suggests some future directions.