The window as a “solar panel”: light transmittance and solar factor g

With this article, we cover two very important aspects of glazings: light transmission and the solar heat gain coefficient.

These parameters are extremely important for performing buildings and passive houses, however they are often overlooked by both designers and window manufacturers. Read More

The glass edge thermal bridge: the PSIg value

We continue our series of articles on thermal efficiency of windows, describing the glass edge thermal bridge.

As far as thermal bridges go, this one is inevitable, and it represents the weakest point of a well designed thermal envelope. It needs to be analyzed carefully, in order to prevent condensation (or ice) to form on the edge of the glass, discomfort, and an overall drop in the performance of the window/door. Read More

Thermal transmittance U vs th. resistance R

To achieve thermal comfort and energy efficiency in buildings, a primary role is played by the thermal envelope: this is required to thermally decouple the indoor environment from the ever-changing external conditions, both in summer and in winter.

The structures of the thermal envelope need to be able to control the amount of heat migrating through them: the thermal resistance and the thermal transmittance are two ways to describe this phenomenon. Read More

What’s an insulation material?

With more and more people talking about building energy efficiency and passive houses, it has become more and more common to hear about insulation. In this article, we explain what an insulation material is, to try and shed some light on the topic, and bust some myths. The energy efficiency of a building, as well… Read More

Thermal bridges: the temperature factor fRsi

We continue our series of articles on the topic of thermal bridges: this time, we illustrate the fRsi value, which describes the thermal ”strenght” of a node under the point of view of internal surface temperatures.

As we have explained in a previous article, the PSI value describes a higher or lower heat flow caused by a discontinuity in the thermal envelope – a thermal bridge – the fRsi factor is of primary importance for health and comfort considerations. Read More

Thermal bridges: the PSI value

For new builds as well as energy retrofits, worldwide the construction industry is shifting more and more towards zero energy buildings and Passive Houses.

With the thermal envelope becoming more and more advanced, the correct evaluation of thermal bridges becomes critical: with this article, we explain the PSI value. Read More

The compactness ratio of a building

When addressing the energy efficiency of a building, one of the most important players in the game is the compactness of its thermal envelope.

Is there a way to measure the compactness of a building? Yes: it’s the compactness ratio. Read More