Target values for indoor environment in energy-efficient design

Abstract

This chapter summarises the factors which should be considered in the design and operation, focusing mainly on room temperature, indoor air quality, ventilation, moisture and humidity, noise and lighting. The information is mainly based on the European Standard EN 15251:2007, but as this standard does not cover all indoor environmental factors to be considered in low-energy building design also other sources are used. Many certification systems for buildings include in the evaluation criteria both energy use and the quality of the indoor environment. Thus, it is desirable to develop systems and solutions which lead to high-quality indoor environment with low energy use. The designer shall always document design criteria for the indoor environment; these criteria shall be available with the energy use data when renting or selling the building space. It is also recommended that design values for the indoor environment and indicators for the environmental comfort are included in the energy certificate and displayed with actual values for the energy use. This chapter describes also the difference between target values for dimensioning of systems and energy calculations. Different approaches for mechanically cooled buildings and buildings without mechanical cooling are introduced, and precautions are given for the latter if to be applied in low-energy buildings.