It is common to control several rooms in a
building with a single sensor in one of the rooms and a
single actuator driving just one control element such
as an air damper. New, low-cost, wireless sensor
technology now offers the opportunity to replace the
single sensor in one room with a network of sensors
having at least one sensor per room. This paper
addresses this multi-sensor, single-actuator control
problem. We used computer simulations and
optimization to study the problem. We designed a
computer simulation of the heat transfer behavior of a
section of a building that accounted for the effects of
weather, building materials, ventilation, and loads
from occupants and equipment. We considered ad hoc
methods (such as averaging) of using information
from multiple sensors. We also developed a new,
model-free method of using information from multiple
sensors that is based on a simple optimization
procedure. The optimization procedure can be
configured to optimize comfort or to optimize energy
under comfort constraints. We compared the
performance of the single-sensor strategy with the ad
hoc strategies and optimized strategies using annual
simulations of a four-room, perimeter section of a
building and weather data from Sacramento,
California. We report heating and cooling energy
performance along with two comfort metrics, the
average number of rooms within the ASHRAE
comfort zone and the Predicted Percentage
Dissatisfied (PDD). The results show that most of the
multi-sensor control strategies do better than the
single-sensor strategy on the basis of both energy
performance and comfort. The energy-optimal
strategy reduces energy consumption by 17% while
reducing PDD from 30% to 24%. The
comfort-optimal strategy reduces energy consumption
by 4% while reducing PPD from 30% to 20%. The
performance improvements occur primarily when the
average load among all rooms is nearly zero, with
some rooms requiring heating while others require
cooling. Under these conditions, the single-sensor
strategy either overcools or overheats, whereas the
multi-sensor strategies use almost no energy