EFFECTS OF CEILING FANS ON THE THERMAL COMFORT OF STUDENTS IN LEARNING ENVIRONMENTS OF BAYERO UNIVERSITY, KANO, NIGERIA
DOI:
https://doi.org/10.56892/bima.v6i01.348Keywords:
Ceiling fans, thermal comfort, overheating, Bayero University, KanoAbstract
It is well known that thermal comfort is influenced by major physical parameters; air and radiant
temperatures, humidity, and air speed in combination with personal attributes; clothing insulation
and activity level. Although temperature is conventionally considered in adaptive thermal
comfort model, as the most important physical parameter where cooling is involved, moderate
air speed can enhance thermal comfort during higher temperatures. Through convective and
evaporative cooling, ceiling fans cool people by causing sweat from the occupant’s body to
evaporate. The northern part of Nigeria, being in the tropics, is known for higher temperature
regimes for most part of the year. The use of air conditioning to achieve thermal comfort is not
sustainable, for economic reasons and the lack of stable electrical energy. Therefore, a majority
of naturally ventilated spaces could be kept thermally comfortable with the control of ceiling
fans and operable windows. As part of a research work on learning environments in a Northern
Nigerian university, this study reports on the effects of ceiling fans on the thermal comfort
perception of the students in two lecture theatres. In addition to the measurements of air speed,
air and radiant temperatures, relative humidity, a comfort survey was also undertaken in the
spaces, from which activity levels and clothing insulations were obtained. Adaptive thermal
comfort standards, ASHRAE 55 and EN 15251, state that thermal comfort can be maintained as
air temperature rises with the use of ceiling fans operating at moderate speed. The results from
this study show that reductions of 31% and 22% in overheating from the two lecture theatres
were realised, as a result of ceiling fans usage, measured by the degree hour’s exceedance
indicator. These results were further corroborated by the students’ acceptance of thermal
conditions of the lecture theatres at temperatures above Tmax.
