A couple of weeks ago, we took part to the 2016 edition of the Passive House Window Talks. This year, the location was Riga, Latvia.
The focus of the event is the importance of windows for comfort and energy efficiency of highly performing buildings such as passive houses.

Following the 2015 edition in Slovakia, the Riga event gathered architects and designers from Sweden, Norway and Romania, besides Latvia.

The tour of several construction sites allowed participants to see first-hand solutions for air tightness and thermal bridges, which are of primary importance for the good quality of a thermal envelope.

One of the sites visited was the renovation of a building listed as historic heritage. In this case, the windows were particularly interesting, as they were developed to meet at the same time architectural heritage requirements and the passive house standard.

The workshop included the development of projects from the participants in PHPP 9, to meet the passive house standard, in different climates.

Benjamin Krick of the Passivhaus Institut presented the principles of an efficient thermal envelope, based on compactness, thermal insulation and absence of thermal bridges.

The presentation also included case studies of energy retrofits with the passive house standard (see EnerPHit), with great potential for reduction of energy demand for winter heating (in some cases, up to 90%).

Using PHPP 9, Franz Freundorfer analyzed the economic balance of several buildings in climate zones around the world: investing in a good quality envelope is the winning strategy, over the life cycle of a building.

The principles of the thermal behavior of windows were presented in detail, with the support of thermal analyses using finite element softwares. In highly performing buildings such as passive houses, windows are the cornerstones of the thermal envelope.
From the point of view of the thermal balance, in winter a performing window has higher solar heat gains than energy losses, basically heating the building for free. With the proper shading, a good quality window also protects the building from overheating in summer.
As far as comfort, a passive house suitable window has internal surface temperatures that are close to the ones in rest of the room, allowing for even comfort conditions (see image below).

The participants had the chance to work on their own projects, with a preliminary calculation first, and with an advanced one later on with PHPP. The goal was to optimize buildings from an architectural and technical point of view, to achieve the passive house standard in a cost-effective way in different climate zones.

Some participants, who did not bring their own project, worked on the design of one of the two passive houses we are currently building in Cavriago, Italy.

For the first time, in an “experimental” way, the Passive House Window Talks were broadcast across the Atlantic, to the USA.

The 2016 edition of the Passive House Window Talks were a success, with a good number of professionals involved from several countries around Latvia.
Windows play a very important role in the thermal envelope of highly efficient buildings, both for comfort purposes and for the energy balance. The goal of this event is to spread the knowledge and appreciation for good quality windows.
The 2017 edition is planned to take place in Ireland.