An investigation of the impact of green building energy efficiency criteria on the heating and cooling loads of an existing building

Abstract

The building sector worldwide consumes almost 45% of the total energy consumption, placing an emphasis on energy efficiency. Studies show that the HVAC system of a building amounts to almost 53% of the building energy consumption. The building envelope is one major component that affects the size of the heating and cooling system. This project studies the effect of the green building energy efficiency criteria on the size of the HVAC system and potential savings and reduction of CO2 emissions. The building selected is a conventional existing educational building located in Lebanon at one of the Higher Education Institutions. The building was modeled using Hourly Analysis Program (HAP). Calculation of heating and cooling loads was done on the existing building. The orientation of the building was checked to be the best orientation. After applying all the modifications to the building using the green building criteria, a reduction of 30% in the total energy consumption and energy cost was found. Additionally, 90,489 kg of CO2 emissions could be reduced per year if these modifications were to be implemented. Further studies could be made on the impact of lighting while optimizing daylight to reach a better lighting efficiency, which will surely affect positively the efficiency of the HVAC system as well. These numbers prove that an investment is worth doing on changing the glazing type, the floor and roof insulation, and applying motion sensors in the building, that leads to {dollar}30,000 savings each year.