INDOOR AIR QUALITY


BMS and wellbeing


Ian Ellis considers looking beyond just energy efficiency and discusses how BMS can contribute to improving indoor air quality and wellbeing.


Ian Ellis


Marketing and sales specialist manager Siemens plc


www.siemens.com T


organic compounds) and PM2.5 fine particulate matter, which are microscopic dust particles.


here are many varied definitions of smart buildings, but what they all tend to have in common is the appreciation


that a smart building employs technology, not only to enable an efficient use of resources but also to create a safe and comfortable environment for its occupants. At Siemens we see four main focuses in what people want from their smart buildings: flexible space utilisation, digital transformation, a demand for health and safety, and sustainability. The need for flexible space utilisation has grown since COVID-19 reshaped the work landscape, impacting office environments more than anticipated. Companies have re- evaluated their need for conventional office space, with some relinquishing it and others remodelling their working environments. The IoT continues to grow


exponentially, with a modern BMS usually involving significant amounts of data from potentially thousands of system devices which are constantly sending and receiving information. Health and safety has become


a greater focus too. Ensuring that the working environment is not only safe but is actually conducive to promoting the health and wellbeing of a building’s occupants is now very much the goal. Likewise with sustainability, as buildings are the biggest single source of energy usage. Add to this the pressures on energy prices plus the increased introduction of green regulations and it is easy to appreciate why sustainability is high on the building and construction agenda.


Diff erent levels of automation BMS can help to address all of these issues. The level of automation dictates just how much control is


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available, from basic entry-level systems through which management is based on room demand, right through to systems which effectively automate the whole building operation – heating, lighting, air conditioning, cooling, shade control, and door and window technology. These can all be networked to communicate with each other to enable central control through intelligent BMS. Energy efficiency is a key driver for


BMS. The BACS Energy Performance Classes in EN ISO 52120-1 provide a guideline for the strategies which can be adopted through a demand/ control based system. It ranges from the inefficiencies of Class D through to the highest performance represented by Class A. By raising a building’s performance from Class C to Class A, energy savings of up to 30% can be achieved just by improving the design and implementation of a control system.


One of the major advances made


in improving the energy efficiency of buildings has, however, actually worked against their performance in terms of occupant well being. Older buildings were typically well ventilated whereas new buildings are designed to be practically airtight. While this certainly improves energy optimisation, a consequence is that fresh air is no longer getting into buildings. The air quality in a building can therefore suffer, with more CO₂, higher humidity and an increase in pollutants. Research suggests that the


majority of people spend some 90% of their time indoors so the indoor environment is key to our health, particularly in light of the fact that


Graphics that visualise historical trends can provide meaningful insights


pollution is typically 2-5 times higher in indoor spaces. In fact, poor ventilation may account for more than 50% of all sick leave. For those that are not so adversely affected that they require time off, office work performance can still fall by over 9% as a consequence of poor indoor air quality. We have all been in buildings where poor ventilation has created a stuffy environment which directly impacts on our cognitive performance. It is also not only short-term


consequences for our health that need to be considered. Those constantly exposed to unhealthy environments can suffer a range of longer-term conditions, including high blood pressure, an increased heart rate, and kidney and bone problems. Such issues have raised the profile


of how control systems can be managed, not only to improve energy efficiency but also to deliver better health for those that are using them. There are essentially nine


foundations to a healthy building: ventilation, air quality, thermal comfort, moisture/humidity, dust/ pests, lighting and views, water quality, noise, and safety and security. Returning to indoor conditions,


studies suggest that 40-60% relative humidity is ideal for indoor human health and reducing virus vitality. With each person delivering approximately 8 litres of air per minute through breathing, the released air contains CO₂ plus droplets and aerosols. CO₂ levels should be kept below a certain level to help provide wellbeing for occupants. Attention should also be paid to VOCs (volatile


Monitoring and control Firstly, you need to be able to measure these values and then you need to be able to put controls in place. This is where an effective BMS comes in, central to pursuing a green building certification (examples are Well V1, Reset, LBC, Fitwel and LEED). In its simplest form this can be just ventilation control, monitoring and adjusting temperature for example. The next stage is demand controlled ventilation (CO₂-based), which improves air quality and saves energy. Even more effective is demand controlled ventilation with active filtering which introduces more fresh air by dynamically analysing the outside air conditions, creating accurate air pressure drop control, generating the same amount of air and filtering out PM2.5s but using less energy to do so. Research suggests that keeping


CO₂ levels below 1,000ppm can increase productivity by between 2-18%. As already stated, humidity levels from 40-60% are perceived as ideal, reducing virus transmission by up to 70%. By controlling the level of indoor volatile organic compounds (VOCs), sick building syndrome can be avoided reducing absenteeism and improving productivity.


Connecting the dots With the shift towards a more holistic approach to managing a building in terms of its active contribution to the wellbeing of its users, so the need for connectivity of the sensors and control devices is becoming ever more important. Solutions are now available which allow daily building management tasks to be undertaken from one place via a cloud-based interface with no additional gateway or software. Alarm notifications for potential issues as well as graphics that visualise historical trends can provide meaningful insights into the building performance at any time, supporting the optimisation of building operations. Intuitive online access can be


available via desktop or smartphone, with installation achieved via plug and play, so system integrators, technicians and facility managers do not need engineering skills to set up, configure and operate systems. It is important that such interfaces can support a range of communication protocols to optimise connectivity (wired or wireless) – BACnet, LoRaWan, M-Bus, Modbus and KNX are all protocols used in BMS. ■


EIBI | JUNE 2024


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