Erik Bjørn

Impact of Open Windows on Room Air Flow and Thermal Comfort

Abstract In the design of natural ventilation systems, there is a wide range of possibilities with regard to the selection of window type and the positioning of windows in the facade. Each window type has unique characteristics, which affect air flow and thermal comfort conditions in the occupied zone. A combination of various window types and façade locations in a room should be capable of improving thermal comfort and minimising draught risk. This paper describes the results of laboratory investigations in a mock-up of an office space with the purpose of investigating the impact of different opening strategies on thermal comfort conditions in the occupied zone. The results show that different window opening strategies result in quite different air flow and thermal comfort conditions. The conditions are a result of a multivariable impact, and thus detailed descriptions of the flows involved are quite complex.

An Iterative Assessment Concept for Building Design Based on the Eco-factor

Abstract Problems in office buildings are often related to the design and control of the indoor environment and of the building as an energy system. The often interconnected nature of the above two issues is important to take into account, since, for instance, internal and external heat loads, temperatures, and air change rates affect both energy use and indoor comfort. Thus, to avoid the indoor climate problems, it is essential that energy optimisation is integrated with assessment of indoor climate. An assessment concept based on the so‐called Eco‐factor has been developed; it can assist building designers in creating solutions of these problems. The assessment concept is meant to be an integral part of new design guidelines for office buildings, which aim to achieve energy efficient buildings with a good indoor comfort and low environmental impact. The building designers have different needs at different stages of the design process. For this reason, the assessment concept makes use of the Eco‐factor t...