LOW-COST SENSORS FOR BALANCING INDOOR AIR QUALITY AND ENERGY USAGE

Saving energy and improving Indoor Air Quality (IAQ) and thermal comfort in buildings are traditionally competing goals. Facilities that manage one of these objectives well tend to compromise the other. Building Automation Systems (BAS) have been limited in their ability to sense these characteristics of a building and therefore cannot act on them. A majority of buildings define IAQ in terms of supply air temperature alone and manage energy consumption by scheduling. There is a large potential to improve both IAQ and energy consumption through innovative control strategies. These strategies are independent of developments in the energy conversion equipment itself by enhancing its control. Good control requires good feedback and feedback for IAQ is complicated by a lack of sensors able to be easily integrated into BAS that can record other contributions to IAQ such as CO2 and the presence of trace gases. Since BAS have not traditionally had access to this type of data, there is little experience of how to best apply this new information in a dynamic system to achieve reduced energy consumption while improving IAQ. This paper will discuss development and integration of low-cost microsensor arrays into affordable BAS. Multi-function sensor packages are in development that can measure CO2, temperature, humidity, room occupancy, and potentially other trace gases of interest. The sensor package can communicate with the BAS wirelessly or over existing building power wiring. Communications have been developed for a low-cost implementation with algorithms focused on security and robustness