Introduction to the energy use assessment

In each of the 10 participating countries, a national energy expert was appointed to collect data during field visits to the schools and preliminarily review the gathered information. The energy questionnaire was developed through a process of review and discussion among all the participating energy experts and in collaboration with the REC SEARCH II management team and Comfort Consulting Ltd., Hungary. The questionnaire gathered information on:

  • the total heated floor area of the building (m2);
  • the total heated air volume in the building (m3);
  • the surface area (m2) and heat transfer coefficients (U, W/m2K) of the external walls, windows, doors, roof etc.;
  • the heating, domestic hot water (DHW), cooling and air handling systems:
    • type of heating and DHW system;
    • heating medium (water, steam);
    • heating system network (one-pipe or two-pipe system);
    • type of heating appliances;
    • type of cooling equipment (air conditioning);
    • type of air handling units;
  • the control of the heating system;
  • periodical temperature reductions (nights and weekends); and
  • annual heat (gas, district heating, oil) and electricity consumption.

The questionnaires completed by the national energy experts were returned to the REC and Comfort Consulting Ltd. for validation and energy calculation. As a first step, the input data from the questionnaires were analysed and the distributions of the different parameters were examined. In a follow-up step, a common energy calculation method was chosen (the Hungarian TNM Decree 7/2006). The specific heat loss coefficient, total primary energy and annual gas, district heating and oil consumption were then calculated.

The calculation was initially based on the assumption that all the buildings were located in the same place (i.e. Hungary), as the goal was to compare the results from the different schools. Two indexes were created, school by school, in order to compare the buildings from the point of view of thermal characteristics: the building envelope index (qi); and the energy index (ei). In a second calculation, the calculated heat consumption data were corrected with the heating degree day factor and compared with real energy consumption, according to real location. Recommendations were given for the modernisation of the building structures and for heating, ventilation and air conditioning (HVAC) systems, based on the results of the calculations. Finally, the effect that modernisation would have on energy consumption was analysed.

 
Ministero Dell'ambiente Italian Trust Fund