This is an introduction to BeMS systems for people who are new to the industry
The importance of buildings in our day to day life can be easily overlooked. Given that we are spending over 90% of our time indoors, we have grown accustomed to our usual surroundings without fully appreciating their impact on our wellbeing, their environmental footprint, and associated costs.
These points barely scratch the surface, many more enter the equation when considering the location, occupant type and operational requirements: getting the right tool (building) for the job is important.
Simultaneously, when considering occupant orientated buildings as opposed to building orientated occupants, we must account for energy consumption, to both save money, and to ensure that our buildings are positively contributing towards the battle against climate change and achieving Net-Zero goals.
Parts of the building function in a similar way to the parts and subsystems of the human body.
The architectural Design represents the skin; structural design the bones, heating, ventilation and air-conditioning (HVAC) the Organs, and the BMS can be considered to be the brain and central nervous system.
Whilst the architectural design (skin) and structural design (skeleton) remain static post-completion, the HVAC (organs) and BMS (brain and central nervous system) operate continuously, where BMS directly monitors and controls HVAC systems, just like our brain controls our organs.
As we utilise our brain more and more to learn new things we consume more data. More information is absorbed and, in return, we can make ‘data-driven decisions’ whether that’s derived from study or experience. Similarly, a BMS system can become more intelligent by capturing more data and provides a better functional built environment.
On a high level, it is relatively simple; all we need is four elements:
A variable that is required to be controlled such as temperature, air quality, humidity
A device that can read the value or magnitude of the parameter.
The controller has identified what is required to be done, i.e. temperature levels within a space are too high, the controller switches on the air conditioning, or to supply cooler outside air into the space, or if the temperature has dropped, the boiler is switched on to supply more heat through radiators.
A device which implements a logic or intelligence and decides if the state of the parameter is correct/incorrect, and what is required to be done.
The common misperception that BMS only controls temperature levels within a building very often overshadows many other major factors which need to be considered when designing, commissioning and operating our buildings, we must thing beyond temperature control.
BMS functionality can be split into 4 major components:
The most obvious one is to monitor, control and optimize energy consumption, decrease carbon footprint and energy cost.
Recognize equipment performance discrepancies, anticipate common faults, hence avoid equipment blackouts or downtime.
Controlling the temperature, air humidity, lighting, air quality, water temperatures.
Environmental control leads us to one of the most important factors to be considered within the built environment, which is wellbeing and Comfort, it’s all about the occupant, the building is designed and operated for human activity, hence the design and control of this space should be oriented around the occupant.
To illustrate the significant importance of control system on our wellbeing and comfort we will use a particular example, such as air quality and its effects on the building’s occupants.
To investigate the effect of air quality, we will look at how the concentration of CO2 affects people. At the levels we are looking at, the unit of concentration used is parts per million, (ppm) i.e. the concentration of CO2 molecules per million of other air molecules.
Insufficient air quality measures such as ventilation can directly lead to an increase in CO2 concentration which has a negative impact on the behaviour of the people in the room, as shown in the figures below, Cognitive performance declines as CO2 increases.
We can conclude therefore that poor air quality can significantly impact occupant wellbeing which in return can have a negative impact on business performance and the bottom line.
Although a Building Management System may be considered the black art of the industry, it is inherently simple. The basic function of such a system is to monitor and control, while providing the best environment for the occupant, decreased energy consumption, either to reduce costs, or out of ecological concerns, and to minimise downtime due to failure of plant or other equipment, such as freezers in a supermarket.
This blog was researched and written by Ivo Krastins.