When it comes to clean energy and reductions in global emissions, most eyes turn to the transport industry, with some cities promising combustion engine-free centres within the decade. Cities across the world, however, currently house half the population, with over 4bn people living in urbanised areas, and projections showing that by 2050 there will be another 2.5bn added to that. Climate experts are quick to point out that it is not just how these people get around that needs to be addressed, it is how they live and work.
The demand for cities to act in reducing emissions and energy usage is climbing, with mounting pressure being applied to business owners and architectural engineers to achieve sustainability and net-zero carbon footprint as urbanisation increases. And this pressure not only falls at the door of new buildings. According to the UK Green Building Council (UK GBC) over 80% of the buildings we will be using in 2050 are already standing today. Fortunately, Smart Building technology is advancing, with the majority allowing for retrofitting, which means this mounting pressure should result in decarbonisation of our existing buildings, the impact of which being nothing other than cleaner air and well-being for officegoers and city dwellers.
Here we look at ways in which Smart Buildings are paving the way to cleaner cities by harnessing natural and renewable energy and making their environmental control systems work smarter, not harder.
Temperature Control
Temperature control is by far the element of commercial buildings that consumes the most energy. As soon as moving parts are added to the equation, such as fans, energy usage begins to skyrocket. Add to that power-hungry refrigeration units and air conditioning quickly jumps to the top of the list of concerns for energy-conscious architects and building planners. The fact that the bi-product of an air conditioning unit is heat tells us all we need to know about the energy-efficiency of these systems, but Smart Buildings are set to put some of these shortcomings to use. More on that later.
Automation is the first step in reducing the energy-consumption of a Smart Building’s air conditioning system. Most of us have been in a hotel where the air conditioning unit in your room only works when a key card is present, which means the unit isn’t running when no one is in the room. Smart Buildings take this one step further: no longer can the more astute (or underhanded) clients simply put a business card into the slot to fool the system into keeping the A/C on 24 hours a day — occupancy sensors detect whether nobody is in the room and deactivate the air conditioning after a short period of time.
When it comes to Smart commercial and office buildings, temperature, occupancy, and humidity sensors constantly communicate to the air conditioning system to ensure rooms are not being over-conditioned. Meeting rooms are linked to electronic calendars, with Smart air conditioning systems calculating the amount of time required to cool the room, based on the volume of air to be cooled and current temperature, and then switching on at the precise time needed to achieve the desired temperature.
Heating through ‘solar gain’ (ie sunlight) is both a blessing and a curse. During the warmer months sunlight can heat a room to undesirable levels, meaning air conditioning systems in non-Smart Buildings must be running to keep temperatures to a comfortable level. This battle is amplified by glass (the greenhouse effect in action) and with over 11,000 glass panels London’s Shard is particularly exposed to this issue. To mitigate this effect, the Shard has triple-glazed windows with a special coat of sun-protection between the inner and outer panes. Secondly, the Shard has an intelligent blind control system which automatically closes and opens blinds to maintain an even temperature throughout the building depending on the position and intensity of the sun.
Radiators are still prevalent in most commercial buildings in the UK, and the efficiency of these more antiquated methods of heating are being refined even in 2021. Smart thermostats on the radiators communicate wirelessly with sensors and adjust mechanically where necessary. Also, more attention is being paid to the location of these sensors and the groups of radiators they control, with radiator thermostats leaning more towards controlling single radiators rather than multiple in the same or even different rooms.
Lighting
Smart Lighting has been with us for some time, as have more energy-efficient LEDs that are arguably the standard for modern lighting solutions. But Smart Buildings are looking further than simple motion sensors that govern the on/off status of one or more lightbulbs — when it comes to energy efficiency lighting control is becoming more nuanced.
The typical process of setting up a meeting room most likely includes switching on the lights and setting the air conditioning. It’s unlikely that the person tasked with setting up this room will pay much attention to the weather and brightness levels, with the switching on of the lights falling into the “better have them on just in case” train of thought. Smart Buildings are combatting this by automatically adjusting lighting levels based on environmental factors. For instance, in the scenario where the lights of a meeting room are on, the blinds are almost closed, and it is sunny outside, a Smart Building can automatically open the blinds and lower the electronic lighting to achieve the perfect ambient lighting level, thus saving energy.
Advances in LED lighting technology can already achieve 50% energy savings over legacy technology, and with the advent of these motion and light sensors, and the use of environmental factors to determine required usage, experts suggest the impact could be a further 60% reduction over the savings already provided by simply switching to LED technology. It is this use of existing and renewable energy, whether its heat or light, which is at the forefront of Smart Building technology.
Renewable energy
Renewable energy is perhaps most widely understood concept when it comes to energy efficiency. Solar panels are standard fare for commercial and residential buildings, and wind turbines are now being installed on taller buildings to harvest that free, renewable energy being so readily distributed at higher altitudes. Advances in solar technology is allowing solar film to be applied to windows, and with glass making up almost 99% of the external surface of modern office buildings and skyscrapers this is an exciting innovation that is sure to take renewable energy to the next level.
Batteries can be found in modern Smart Buildings, which store unused energy harvested by renewable energy systems after the energy needs of the building have been met. What is more, Smart Buildings with this kind of energy infrastructure can distribute this unused energy back to the grid, essentially expanding the energy efficiency of the building to the city as a whole.
Although not renewable energy in the strictest sense, the heat output from air conditioning systems, which is essentially a waste product, is being put to use by Smart Buildings. By repurposing this energy to heating water and areas of the building not exposed to solar gain, i.e. basements, Smart Buildings are helping mitigate the massive amount of energy used by these air conditioning systems where natural alternatives are not available.