Active solar heating was a favorite topic after the first energy crisis. Usage for space heating, however,proved to be completely uneconomic. Domestic hot water systems, instead, retained attention. Theycan be used year-around and have a much larger share in the hot water energy bill than space heatingsystems have in the heating bill. Of course, in the past, energy use for domestic hot water wasonly a fraction of the energy needed for space heating.
This paper presents the energy and economic analysis used to determine cost effective requirementslevels to the thermal standard for buildings in Lebanon. The heating and cooling energy use fordifferent buildings types (18 buildings) according to the variation of envelop parameters was simulatedfor realistic cooling and heating schedules and five Lebanese climatic zones. Parameters investigatedincluded, construction type, insulation levels, window sizes and solar protection. The energysimulation program VISUAL-DOE.3 was used for the energy use simulations.