A DESIGN ANALYSIS PROGRAM FOR SOLAR HEATED AND PASSIVELY COOLED HOMES IN BURUNDI

Abstract

Two design analysis programs that model the performance of solar heated and passively cooled homes in the climate of BURUNDI are presented. The new programs, SOLBUDI and COLBUDI, are based on the design analysis programs SOLASEC and COOLASEC which have been modified to account for skylights, solar heat gains on wall and roof surfaces, as well as nocturnal radiation effects on the roof. Additionally, Bjumbura (∼ 800 meters in altitude) weather data and the thermal properties of building materials commonly used in Burundi are incorporated into the programs. Typical weather data for cities at mid-altitudes (∼ 1500 meters) and high altitudes (>2000 meters) are also presented. Due to the great variation in altitude (700 meters - 2600 meters) and climate in Burundi, both heating and cooling are required, hence the need for both heating (SOLBUDI) and cooling (COLBUDI) design analysis programs. Skylights, east windows, and west windows are the best sources of solar gain in Burundi due to the high solar angles, which are present all seasons. Thus, solar gains through these apertures must be controllable to prevent overheating during the warm season.