Motorised blinds: a key part of a dynamic façade
We spend 90% of our time in buildings, which are responsible for 40% of global energy demand. Never has the need been greater for buildings to respond intelligently to both the people inside them and their surrounding environment. Motorised blinds can play an important part in the efficiency of façades, generating potentially huge energy savings for building owners and healthy, productive internal environments for tenants.
No automation, no point
The temptation to save money on up-front costs by swapping to manual blinds is a very expensive move in the long run. The massive benefits of properly engineered solar shading systems can only be harvested correctly if the system is automatically controlled*. A year-long scientific study by ESTIA** concluded human behavior collides with efficiency when blinds were operated manually. It analyzed over 500,000 pictures looking at how blinds are used and concludes that manual blinds are moved less than twice per week!
Automation means that the shading will work properly even when people are absent. Without this automatic reaction to environmental conditions, and coordination with other automatic building services, the corresponding energy savings are lost.
Energy savings for building owners
Motorised shading integrated with precise daylight tracking software and an appropriate BMS can constantly adapt to the external environment and significantly reduce the requirement for mechanical heating, lighting and air conditioning.
Even with the most effective solar control glass, the right kind of blind can save almost half of the energy typically used for air conditioning and lighting (see Chart 1). To put that into a context that we can all understand, a recent PhD study at South Bank University sponsored by the BBSA examined a block of flats in Camden where the internal air temperature in summer reached 45°C, the same as a typical day in Death Valley. The study found that even medium performance blinds could make a difference of as much as 18°C.
Productive, healthy environment for tenants
According to the Harvard Business Review (9/3/18), the number one office perk for employees is natural light and views to the outside. The World Green Building Council adds weight to this argument, proving through its research the dramatic impact that natural daylight and views to the outdoors have on human behavior. A connection to the outdoors makes us healthier, helps us to work better, and makes us happier.
The silver bullet: Early collaboration
Today’s dynamic building envelope must include integration of shading, lighting and HVAC systems that constantly respond to their surroundings. The only way to get it all right is proper collaboration between specifiers, engineers, and product manufacturers early in the design process. In most cases, this is still not happening. Reliance is often placed on building services engineers in the unrealistic expectation that they should somehow know it all.
There are a growing number of more holistic ‘Environmental Design Consultants’ as well as integration and controls experts operating within the larger, multi-disciplinary façade engineering practices who do have the potential to facilitate genuine early collaboration. Those that do this successfully will produce buildings that truly harness the power of light and shade as positive environmental and architectural features, rather than creating problems to be overcome later.
**(Source: ESTIA – GLOBAL LIGHTING PERFORMANCE )