Low-Cost Networking for Dynamic Window Systems

A low-cost building communications network is needed that would allow individual window and lighting loads to be controlled from an existing enterprise LAN network. This building communications network concept, which we term IBECSTM (Integrated Building Environmental Communications System), would enable both occupant-based and building-wide control of individual window, lighting, and sensor devices. IBECS can reduce the cost of systemic control because it allows a drastic cost reduction in per point networking costs. This kind of effort is needed to encourage the control industry to make the commitment to build this technology and to demonstrate to prospective customers that this breakthrough approach to more comprehensive systemic control will provide them with high-quality, convenient control while saving them money. The development and demonstration of network interfaces to DCand AC-motorized shades and to an electrochromic window are described. The network interfaces enable one to control and monitor the condition of these fenestration appliances from a variety of sources, including a user’s personal computer. By creating a functional specification for an IBECS network interface and testing a prototype, the ability to construct such an interface was demonstrated and the cost-effective price per point better understood. The network interfaces were demonstrated to be reliable in a full-scale test of three DC-motorized Venetian blinds in an open-plan office over two years and in limited bench-scale tests of an electrochromic window.