Analysis of Ambient Dry Bulb Temperature and Relative Humidity Data of Ikeja, Nigeria for Refrigeration and Air-Conditioning

Data of 15 years for dry bulb temperature and relative humidity were available. The data were recorded on hourly basis, using the Greenwich Mean Time (G. M. T) as the standard of time. Hourly averages and standard deviation were computed for all the 24 hours of the day. Average daily range, of dry bulb temperature and relative humidity were computed for all the months in the year. Models were developed for the diurnal variation of dry bulb temperature and relative humidity. Values predicted with these models were compared with values computed from measured hourly data and the agreements are quite good. Olorunmaiye et al (2015) in a recent study confirmed that the agreement between the models developed in the present study and those developed using the data of 1995 to 2008 was very good. Negative values of cross-correlation coefficients were recorded throughout for all the months for the 15-year period. Statistical estimates were made for 5 %, 2.5 % and 1 % design values of dry bulb temperature. Estimates were also made from the actual distribution of ambient dry bulb temperature. Statistical estimates were also made for 5 %, 2.5 % and 1 % design values of ambient relative humidity. From the analysis, it was established that maximum cooling design temperature does not occur in July in Ikeja, which is contrary to Carriers assumption.