Simplified Procedure For Estimating Air- Conditioning Cooling Load In Ghana

Undersized or oversized air conditioning equipment leads to high operational cost, frequent breakdown and accelerated wear of equipment. Wrong sizing of equipment is often the result of inaccurate procedures employed to estimate the cooling load of the air conditioned space. Today, computer programs are available on the market for more accurate estimation of cooling load. All the same, what appears to be the established practice among service providers in the air conditioning industry in Ghana is to size air conditioners for all applications by multiplying the net floor area by cooling load factor to estimate space cooling load. Availability of cooling load factors that take into account the space operating conditions will be a more accurate and user-friendly tool for such service providers. The Transfer Function Method (TFM), a well-known cooling or heating load estimation procedure that has been adopted by ASHRAE, was used in this research to predict the hourly and daily average cooling load due to different types of walls, roofs and fenestration that are typically found in building construction in Ghana. This has been used to develop cooling load factors that simplify load estimation with a worksheet. The outputs of the worksheet were compared with the result of cooling load estimated using a computer program and the results were found to be satisfactory. The present work will help minimize the problems of higher initial investment and larger energy consumption by auxiliaries, due to over-sizing A/C equipment and the general discomfort during the peak hot season in Ghana, due to under-sizing of A/C equipment. Key Terms: Cooling load,worksheet, load factors, design condition. ————————————————————