Proof of comfort in buildings via thermal building simulation

Today, sustainably designed buildings are in the focus of building planning. To make sustainability measurable, the German Sustainable Building Certificate was created in 2008. This rating system defines standards to be kept for new office and administration buildings in the fields of ecological quality, economical quality, sociocultural and functional quality, technical quality, process quality and site quality.

The sustainability of the project is documented by a certification. Here, depending on the number of points that has been achieved, as to the measured quality of sustainability it is distinguished between three quality classifications (Bronze, Silver, Gold) .

The following validations can be achieved in the latest version of 2009:

• Bronze: at least 50% of the maximum number of points
• Silver: at least 65% of the maximum number of points
• Gold: at least 80% of the maximum number of points

An overview on the DGNB evaluation is given in the following summary:
German Sustainable Building Certificate.pdf

The assessment of sociocultural and functional quality has an impact on sustainability assessment to a percentage of 22.5%. In general, it describes the building physical quality (thermal, visual, acoustic comfort, indoor air quality) and functional quality (lack of barriers, accessibility, reversibility) of the building.

Checking the sociocultural and functional quality, thermal comfort is to be proven throughout the entire year. Doing this task, 80% of the effective area is to be described representatively. The acceptance of indoor climate is decisively determined by air temperature, air movement, air humidity and temperature of the spatial surfaces surrounding the people. In the simplest case, these can be described by specifying the design conditions.

To maximize the assessment of thermal comfort, thermal building simulations have to be applied for the criteria of temperature comfort and radiation asymmetry. With a thermal building simulation these criteria can be evaluated during the course of the year. Thus, on the one hand, as to temperature comfort in summer, the frequency of temperature exceedings is determined, and on the other hand, the frequency of temperature shortfalls is calculated to find out about temperature comfort in winter. For the assessment of the radiation temperature asymmetry, maximum and minimum surface temperatures of large-scale, heated and cooled building surfaces and interior shading devices are calculated.

The consulting engineers b+e offer this service for thermal comfort checks according to criterion 18 and 19. According to the individual task, we use the appropriate thermal simulation programs (IES, TRNSYS, ECOTECT) to check and optimize thermal comfort.