Share this Post
As the experts know for sure, commercial buildings are subject to operational, functional, and occupant changes that put a strain on the mechanical, electrical, and control systems which can eventually lead to a subpar building performance with the passing of time.
Today’s commercial buildings are somewhat complex with intricate designs, sophisticated systems and controls that are dependent on each other for efficient performance. Therefore, even small problems have the potential to set off a chain reaction that ultimately impacts building performance negatively.
The outcome is not only unpleasing but leads to more expenditure in energy bills, utility cost, equipment downtime, and even decreased productivity from occupants. This has led building experts to come up with a process known as Retro-commissioning that can improve the overall performance of a building.
Understanding Retro-commissioning
Retro-commissioning is a systematic process designed to improve the performance of equipment and systems in an existing building. This also might include correcting errors that occurred during the design or construction phase of the building. Other issues retro-commissioning attempts to address include problems related to the address, function, and comfort of the building that might have cropped up as the building and its systems age or these issues might be due to changes in the use of a building. Consider Retro-commissioning as an engine tune-up for buildings.
The process involves measures targeted at correcting operational and control systems; servicing of building equipment; replacements of equipment; retrofitting; and changes in design and installations.
Most commercial buildings will benefit from this process. However factors such as age; overall building condition; unexplained increase in operational cost; subpar equipment performance or sudden breakdown; and occupant comfort are indicators considered before a commercial facility is considered for retro-commissioning.
Retro commissioning benefits everyone in a building thus making it an important decision every commercial building manager or owner should consider at some point in the life-cycle of their property. Such benefits include efficient energy utilization and improved equipment performance, which directly leads to a significant reduction in the overall operating cost thus an increase in net income. For occupants, improved Indoor Air Quality (IAQ) and better space temperature leading to better comfort and performance are some benefits they will enjoy. Fewer complaints and good reputation is something building managers can always do with and this can be made possible thanks to the process of building retro- commissioning.
Optimizing Retro-commissioning with Internet of Things (IOT)
Retro-commissioning is concerned with the identification and correction of problems that hinder building performance. It is therefore correct to infer that any measure that can enhance these processes will ultimately lead to a successful retro-commissioning project. One such way is the use of an advanced technology called the Internet of Things or IoT that helps in identifying problems affecting a building.
According to Wikipedia, IoT is a technological concept that means “the network of physical devices, vehicles, home appliances, and other items embedded with electronics, software, sensors, actuators, and connectivity which enables these things to connect and exchange data, creating opportunities for more direct integration of the physical world into computer-based systems, resulting in efficiency improvements, economic benefits, and reduced human exertions.”
The value here as far as commercial building retro-commissioning is concerned lies in the ability of IoT to automate operations and also supply decision makers with real-time and accurate data that can thus be used to identify issues that are affecting the performance of the building.
Identifying building problems with IoT
The identification process is important and directly related to the eventual success of any retro-commissioning exercise. Fortunately, with IoT, this process can become a breeze leading to cost efficiency and quick project turnaround time.
7 Problems that Retro-commissioning can identify with IOT include:
1. Equipment or lighting control
Energy cost constitutes the greatest percentage of operational cost of most commercial buildings. And the bulk of this cost emanates from equipment and lighting use. Therefore problems affecting these aspects of a building especially those that relates to energy wastage will not only hinder its performance, it will also shorten the equipment lifespan and incur more cost for the managers of the building. And it is for these reasons that retro commissioning might be carried out.
Using IoT, equipment and lighting can be automatically controlled that turns on when they are needed and conversely goes off when not needed. Sensors embedded in the equipment or lighting system will monitor and track the movement and activities of occupants. So you see a situation where HVAC systems will automatically turn off in an empty building without human input.
This enhancement significantly improves building performance since it cuts down on energy wastages leading to reduction in energy costs for building managers. Also, it prolongs the lifespan of these systems because their use is not abused.
2. Problems associated with systems that simultaneously heat and cool
As buildings and their systems age, it is possible for HVAC systems to become out of sync leading to a condition where the system in the building is cooling and heating air at the same time. The scenario can be likened to driving a vehicle with handbrakes. When this happens, energy is wasted, systems breakdown more often due to overuse, and the equipment fails to last its expected lifespan.
If the building is configured to include an IoT protocol, sensors can daily monitor and analyze data gathered from the systems. From the results, the problem can quickly be identified in real-time. Potential issues that can cause simultaneous heating and cooling that can quickly be identified using IoT include problems relating to valves and sensor calibration.
3. Malfunctioning Belts and valves
Belts and valves are integral parts of most appliances such as HVAC systems. They help power other components in the case of belts while valves ensure the integrity of compartments is maintained in addition to ensuring proper direction of air flow. Problems to these items can lead to noise production, rapid wear and tear, and of course poor performance. However with IoT, this problem can be identified right from the source. Power derived from the motor and pressures are some indicators that can be measured to provide useful data that can be used to deduce an ongoing problem with the belt or valves.
4. Thermostats and Sensors calibration issues
The efficiency of cooling or heating is related to the pre-set values of the thermostat and sensors. Unfortunately, over time the calibration can become out of place leading to the HVAC system not yielding the expected results.
Factors that can lead to this condition include dust or debris build up on the thermostat or sensors, wire resistance, over/under voltage, improper thermostat/ sensor location etc. Fortunately, these faults can easily be picked up from IoT supplied data faster without much hassle.
5. Malfunctioning Air balancing systems
Air balancing systems are needed to properly direct airflow within a building. Here airflow rates are measured, tested and adjusted to become “balanced” as cubic feet per minute (CFM) or cubic meters per hour (m3/h).
With older commercial buildings or one with inherent design/ installation flaw it is not uncommon to observe a decline in the efficiency of the facility’s HVAC systems, which can be traced to unbalanced system airflow.
IoT enabled technology can be used to assess factors that can cause unbalanced system airflow. Factors to be considered include design and integrity of the ductwork system, supply and return static pressure, and the output of conditioned air. Additionally, temperature, humidity and heat gains and losses can also be measured using sensors and monitoring devices in an IOT network. Data gathered from this process is then analyzed to determine the extent of the problem and also provide possible recommendations to correct the anomaly.
6. Problems relating to Economizers
Economizers are devices that enable the use of outdoor air for cooling as long as the temperature and the humidity are below a desired pre-set value and percentage respectively. This process of air conditioning is often described as "free cooling" since energy is not needed to operate a compressor.
Sensors are vital in how economizers function. They determine the value of the outdoor temperature, percentage humidity, indoor carbon dioxide levels, return air enthalpy, or outdoor air enthalpy. The data obtained is what is used to determine if an actuator will open a damper in a situation where there is need for cooling.
Faults associated with the dampers, the sensors, and control sequence is some problems that can be identified. Adjustments and corrections can then be made using data supplied from an IoT system.
7. Incorrect controls sequence
Automated systems such as the Building Automated System (BAS) work via a system of iterative command structures. What this means is that actions are controlled or activated as a result of predefined programming and factors. For instance, HVAC systems can be configured to activate ventilation as soon as indoor carbon dioxide levels increase beyond an acceptable set point.
However, in certain conditions especially in older systems or poorly programmed/configured systems, it is possible for the preferred sequence of control to become muddled or haphazard leading to detrimental results. Yet again, IOT technology thanks to sensors, cloud computing and smart devices can quickly discover this malfunction and in certain cases make remediation.
Conclusion
In conclusion, the above problems are some issues that can be identified prior or during a retro commissioning project using IoT. Retro-commissioning using the perks associated with IoT allows commercial property managers to get the most out of their building performance and also improve occupant comfort at a low cost. With IoT, identifying building problems that will be of concern during the retro-commissioning process becomes easy, quick, and cost-efficient.
