REMARK: This Q&A was part of the AIVC special COVID-19 newsletter published in July 2021. To subscribe to the newsletter please click here.

Impact of an occupancy and activity based window use model on the prediction of the residential energy use and thermal comfort

The opening of windows can lead to high energy losses in wintertime, especially in nearly zero-energy buildings. But can reduce overheating significantly in summertime. Therefore, window use models have been created in the past to assess the energy use and thermal comfort in residential buildings. The models are mostly based on weather-variables. However, a recent study (Verbruggen, Janssens, et al. 2018) indicated that these models were not able to accurately predict the window use in wintertime. For that reason, an occupancy and activity based model was developed.

Static pressure and ventilation rates in rooms

The British Standard Code of Practice, and other authoritative guides, recommend minimum rates of ventilation related to the size and use of rooms, and structural means for providing them. But the difficulty of measuring actual ventilation rates suggests that it is seldom done.

Energy saving and thermal comfort in Residential buildings with dynamic insulation windows

To realize the concept of low-energy buildings, an increase in the thermal insulation performance of building parts, especially the openings that show poor insulation performance, is necessary. In addition, an adequate level of thermal comfort is also needed within residential buildings. We have developed window-applied dynamic insulation (DI), and verified thermal insulation performance in chamber and field tests.

Impact of window design variants on lighting and cooling loads: clues for revisiting local building regulations

The study is placed within the context of local building regulations in India. Building regulations, for fenestration in general and window openings in particular, are, to a large extent, ambiguous in nature. In the context of India, observations show that the regulations specify window size for the sole purpose of ventilation whereas windows are major roleplayers in the thermal and daylighting performance of buildings.

Evaluation on energy efficiency of windows in different climate zones of China

In this paper several kinds of window shading are introduced and compared. In addition, the potential of energy efficiency of exterior shading and three representative windows in three typical cities of China are analyzed and compared using eQUEST software. The objective of this paper is to analyze the influence of window shading in different climate zones of China through simulation. The result shows that in freezing climate zone it is appropriate to use the low-e windows with small U-value.

An Experimental Investigation of Natural Ventilators for Improving Indoor Air Quality

Based on the theoretical and experimental studies of natural ventilation, the performance of natural ventilators has been analysed. Four types of natural window ventilators and three types of wall ventilators were studied. Experimental results show that the natural ventilators have a greater ventilation effect whilst meeting national and local standards of ventilation for residential buildings in heating or cooling seasons.  The installation of such devices can be a compromise between ventilation and energy loss.


The SOLVENT window is an innovative glazing system concept that involves the use of a rotating frame, an absorptive glazing and a naturally ventilated vertical channel, in order to improve the balance between the visual comfort and the energy efficiency of windows.

Remodelling how-to's. The ways of weather stripping.


Characterization of the airflow from a bottom hung window under natural ventilation.

For natural ventilation of rooms there is a wide range of possibilities with regard to the selection of window type, size and location. A bottom hung window mounted near the ceiling is often used as it has proved to work well with regard to draught risk and thermal comfort in the room. However, there is a need for more detailed information on the performance of this and other types of windows to make it possible to use improved design methods for natural ventilation systems.