Impact of Indoor Environmental Quality Standards on the Simulated Energy Use of Classrooms

The effect of indoor environment parameters specified in national and international standards on simulated energy use of an educational spaces were assessed. Standards considered included those of EN, ISO, ASHRAE and ISHRAE. Eight different climatic locations were considered. Energy use to maintain IEQ parameters according to the highest category, Cat. I, is two times greater for Category II of the same standard, while the difference is only 15% when category changes from II to III and from III to IV. On the other hand, when the category of a particular standard is shifted one level down, requirements for IEQ parameters are relaxed. If parameters are set to comply with Category II instead of the Category I, operative temperature stays within the range specified for Category I 30% less time, while indoor air quality in terms of the CO2 concentration remains within the Category I requirements 60% less. It is less energy expensive to improve IEQ parameters by moving from setpoints of the Category III to Category II than from Category II to Category I.