A return to buildings that interact with their environment
Advanced approaches to controlling buildings enable them to interact with the external environment to minimise the need for active servicing. Adriaan Jongepier explains how.
The comfort of commercial building occupants should be the first objective for everyone involved in building design, as studies show their well-being and productivity is influenced greatly by their comfort levels. In the past, many buildings have been designed as ‘insulated elements’ separate from their environment. As a result, we have been over-designing artificial lighting and HVAC systems to achieve occupant comfort. However, this approach comes with a very high cost to the environment in terms of high and unnecessary carbon emissions.
Today's new build and refurbishment projects have to ensure that buildings are ‘re-integrated’ into their environment so that they can start to benefit from the abundant and cost-free availability of natural light, solar energy and wind. The creation of new building envelopes, or the adaptation of existing building envelopes, must be undertaken in a manner which allows us to manage light, energy and air flows effectively. This approach will also have a strong impact on the reduction of fossil energy consumption expressed as kWh/m2/year.
In addition, the latest Building Regulations Part L revisions demand a continuing reduction in CO2 emissions. Steps have to be taken to reduce solar gain, reduce internal lighting loads, size systems correctly as well as to undertake energy rating and metering that provides real-time feedback on performance of different building services.
To answer these demands, an integrated design of building façades, internal lighting, heating ventilation and air-conditioning will be needed — including the application of more actual physical data provided by sensors outside and inside the building.
Buildings will need to be Energy Performance Certificated during the design stage as a building's functions are not easy to adapt during its lifetime. The best way to achieve success will be when architectural practices start embracing energy-efficient design from the outset and ensure consulting engineers are involved in the early phase of design.
The concept of bioclimatic facades uses the facade or skin of a building to manage/control the effects of outside environmental factors. The approach is all about smart filtering in the building’s envelope and benefiting from the abundant availability of natural light, solar energy and wind. This approach also creates an energy-efficient, comfortable indoor environment which focuses strongly on the demands of the building’s occupants and which also achieves the energy reduction aims of the building's stakeholders.
By managing the facade through automated solar shading, such as roller or Venetian blinds, the indoor environment can be controlled and adjusted as required. In terms of lighting control, the approach is to prioritise the use of natural light and then add on artificial lighting where and when required. Controls, such as presence detectors and timers as well as high-efficiency LED lighting, will allow the lighting levels required by the user to be achieved in a totally energy efficient way.
With HVAC, the main issues within a building are those of solar gain and internal heating loads. By using or blocking the solar energy in the right way through effective facade management, not only can the result be a reduced capital investment in terms of smaller-capacity appliances/boilers, but operational costs will also be reduced.
Using the vast KNX open-standard product portfolio, facade products can be integrated seamlessly with other building services and their performance monitored using smart metering. The information can be diagnosed via the Internet or a LAN to provide a complete real-time picture of energy consumption, and appliances can be adjusted and managed accordingly.
Adriaan Jongepier is with KNX UK and Somfy.
