Transition Graph Analysis of the Thermal Performance of Two Similar Architectonic Spaces

Previous study results showed that two classrooms similar in size, geometry, and construction and exposed to similar solar radiation – both share an exterior wall with southern exposure and a horizontal roof – have different thermal performance. When mean temperature time series were analyzed, the small differences found were not statistically significant. However, patterns emerged which could indicate the effect that human activity has on the thermal performance of the spaces studied. In an effort to find an adequate way to visualize thermal performance of the similar spaces, as an alternative to the normal time series, a cybernetic focus was decided upon. If the two classrooms are taken as a system, and the dry bulb temperature inside each of the spaces is taken as an ordered pair represented as a point on a Cartesian plane in which the x axis represents the temperature in one of the spaces and the y axis represents the temperature in the other, then the state of the system can be defined as the ordered pair of temperatures. That state will change in time establishing discrete transitions with a frequency dependent on the periodicity of the observations. If both spaces had equal thermal behavior, then the transition graphic would lie on a 45° straight line. Deviations from that pattern would reveal noise, interference and physical differences that were not identified or not considered but which have an important effect on the state variable being studied. This paper presents some of the kinematic graphs obtained and ventures an interpretation.