This International Standard gives calculation methods for assessment of the annual energy use for space heating and cooling of a residential or a non-residential building, or a part of it, referred to as “the building”.
This method includes the calculation of:
a) the heat transfer by transmission and ventilation of the building zone when heated or cooled to constant internal temperature;
b) the contribution of internal and solar heat gains to the building heat balance;
c) the annual energy needs for heating and cooling, to maintain the specified set-point temperatures in the building – latent heat not included;
d) the annual energy use for heating and cooling of the building, using input from the relevant system standards referred to in this International Standard and specified in Annex A.
The building can have several zones with different set-point temperatures, and can have intermittent heating and cooling.
The calculation interval is either one month or one hour. For residential buildings, the calculation can also be performed on the basis of the heating and/or cooling season.
This International Standard also gives an alternative simple hourly method, using hourly user schedules (such as temperature set-points, ventilation modes or operation schedules of movable solar shading).