Frequently you will hear of the term ‘building automation system’ in the function of a commercial office building or retail shopping centre. If you are a commercial property manager you will very likely have come across the terminology; perhaps the building that you manage has a ‘building automation system’ or otherwise called ‘BAS’ installed.
To the uninitiated the ‘BAS’ is the established system that runs a building operationally across many different services and activities. It provides the comfort levels and safety in a building for tenants and customers. If the ‘BAS’ stops working for any reason, then so will the building air conditioning, security, fire safety systems plus a few others.
In a large building there are plenty of things going on at all times. Operationally the building is maintaining safe and comfortable occupancy conditions for tenants and visitors given the pressures of heat, cold, climate, time of day, and costs. The ‘BAS’ allows a closer level of control and monitoring than that which you would get from any manual process or intervention.
Control Systems and Strategies
The ‘BAS’ is essential to building control system given that it is a software system that controls and reports on many switches, valves, cycles, alarms, sensors, and flows across important aspects of property operation. It typically includes (but is not limited to) many if not all of the following:
- Pumps – These items would control flows associated with chiller water, waste water, hot water, sprinkler water, fresh water, and similar important liquid deliveries to essential plant systems.
- Fans – The fans boost air flow into parts of the property subject to the demands of occupancy and temperature. Fans will push air from the main fan units in the air conditioning system, together with outside fresh air when conditions dictate.
- Electrical supply – During the day and into the night there will be variable requirements on power to keep essential plant and equipment systems running efficiently.
- Lighting – This would include common area lighting, tenant lights, emergency lighting systems, and special zones such as car parks, building facades, signage, and stairwells.
- Temperature – The temperature within the building will vary based on outside ambient temperatures, heat loads inside the property, tenant and staff occupancy, time of day, and installed electrical equipment. For that reason there will be multiple temperature sensors in the many zones of the property monitoring temperature fluctuations.
- Car park ventilation – When you have a car park in your property, be it an office tower or retail shopping centre, the toxic fumes from car exhausts have to be detected and evacuated from the car park space. In properties with large car parks or lots of vehicle movement, the matter is real and active. Normally detection systems, alarms and fans will do the job. The automation system in the building car park will monitor and activate the ventilation process.
- Boilers – They supply heat and hot water to the building operational plant. If the boiler in a property fails, then there are immediate consequences for the air conditioning and hot water systems in the building.
- Hot water – This hot water supply would integrate into the plant and equipment in the building plus supply hot water to the tenant washrooms. It is normal to have a large hot water loop installed in a property to circulate hot water to washrooms. The alternative is to have a series of large domestic hot water supply systems placed on floors of the building.
- Chilled water loops – Many tenants in a high rise office property may have supplementary air conditioning systems to provide comfort conditions in their premises and to help with their staff activities and levels. Most separately installed tenant air conditioning systems will require chilled water to function unless some other process locally is deployed. The building could thereby have and provide a ‘chilled water loop’ that allows tenants to tap their air conditioning systems into the building ‘chilled water’ loop. This is a tenant service and should generate a special fee or rental to connect.
- Chillers – As part of the building air conditioning system the chillers supply chilled water to the condenser coils in the plant and machinery in the property.
- Cooling towers – These towers allow the transference of heat from the building air conditioning system before it is resupplied back into the air conditioning system. It is of note that cooling towers and the associated water supply should be treated for the prevention of the build-up of dangerous bacteria and infectious airborne diseases such as legionella.
- Water storage – Buildings store water for all types of reasons. Generally those situations include supply of fresh drinking water, sprinkler water for fire events, stormwater control, and waste water expulsion. Given the height of a high rise building there will be a series of pumps and storage tanks that allow the efficient transference of fluid to and from many parts of the building. The height of the building will dictate the number of staging and storage tanks for efficient supply and control.
- Sewerage and drainage – Some buildings are located in cities where weather events can be significant both in frequency, ferocity, and potential damage. Stormwater from the building and the site will need to be evacuated safely to prevent property and personnel damage.
- Fire safety – In times of building fire emergency, dedicated pumps and sprinkler water systems need to activate to protect occupants and property; that being done given the design aspects of the building, the current building codes, and the tenants in occupancy.
- Smoke evacuation – Typically smoke evacuation will be from all common areas and stairwells in time of fire and emergency. Fans to purge smoke from the stairwells in a building are a critical part of property safety.
- Emergency evacuation systems and alarms – We know all too well today that emergencies happen in high rise buildings and in any property where people work, congregate, or visit. Every property today has systems of evacuation installed to safely remove people safely from any emergency situation. Alarms integrate into that evacuation system. Some tenants attract a greater level of threat and media attention so the emergency evacuation systems in some properties will have to take into account the special nature of specialised occupants and tenants.
- VAV boxes (variable air volume boxes) – These systems allow the control of air supply and hence temperatures in zones and floors across the property.
- Heater banks and condenser coils – These assist in the establishment of comfortable temperatures in parts of a property, a floor, or a tenancy. To to that there will be separate heater banks and condenser units installed in the air supply ducting around VAV boxes to allow the separate control of airflow and temperature in a zone.
- Power sharing or load shedding – At different times of day and night the electricity requirements of the plant and equipment in an office tower or shopping centre can be adjusted for cost and demand efficiency. Power sharing and load shedding allows savings to be made in power usage, cogeneration power, and solar power across the property.
- Electricity demand – Tenants and visitors to a property will place pressure on power use at different times of day. The power supply in any large building should be monitored for peaks in demand and adjustments to supply. Peak power demand at certain times of day will push up the power costs for the building and thereby impact property operational costs. Many larger buildings will shed demand on electricity at peak times to make savings on energy costs. The timing and use of plant and equipment can normally be tracked in the BAS system and thereby adjustments made where possible.
- Emergency power – The supply of power today can be a challenging issue in any office tower or shopping centre. If the power fails then tenants can lose data and or the ability to communicate. The building can also have issues with security and the movement of people in any power failure.
- Security – In modern buildings today it is normal for tenants to integrate their security requirements into the building security system. This then allows the movement of people across common areas and tenant areas to be fully controlled. Proximity sensors and card readers allow tenants to nominate and restrict access parameters of individual staff.
- Lifts – Some buildings have separate lift monitoring systems. The idea here is that the movement of lifts can be tracked for efficiency allowing for the movement of people, power consumption, and time of day.
With some buildings you can add to the list above given that the complexity of building function will add extra services and systems that require monitoring. So the maintenance issues in a high rise office building or shopping centre are complex and specialised.
Given the items in the list and the important role that they play in the function of an office building or shopping centre, you can imagine the problems that evolve when the BAS system stops working properly (and it does happen). Backup strategies are required.
As with all items of software today, updates and patches are normal with building automation systems, and will need to be installed in the main operating system from time to time. It is also fair to say that some building automation systems are not as good as others, and some cycles that are controlled by the BAS are not as reliable as others.
Check Out Available Systems
Having been involved in the selection, installation, and operation of a few significant BAS systems in high rise office towers and shopping centres over the years, I can say from experience that some BAS systems can be very difficult and challenging.
As a general rule I would never recommend that a newly constructed or planned building install an unproven automation system. Check out other properties that may have a preferred installed automation system to see how the software performs.
If you manage a building with an installed BAS system then someone will need to be fully trained on the operation of the software. In any large building it is normal for the building engineer to be responsible for the operation of the BAS; the engineer will normally be employed on the staff of the commercial property management team.