Abstract
In European countries, because of low fossil fuel reserves, energy saving is one of the primary research goals in every energy
consumer sector. In the last several years, several directives were elaborated by the European Commission to enhance the energy
efficiency in buildings and increase the use of renewable energy sources. In European countries with temperate climates, in a
residential building with a “traditional” insulation of the envelope, heating represents approximately 65 to 75% of the total
energy consumption. Nevertheless, in educational or office buildings, the energy consumption for ventilation and cooling is
notably high. The energy consumption for cooling is strongly influenced by the cooling degree day, which varies year by year.
This paper presents the analysis of cooling degree day variation in the last five years in Debrecen and the summer overheating in
an educational building before and after refurbishment.