Effectively managing all the elements that go into the central energy plant is a big challenge for facility managers, reports Nicholas Heydon.
Central energy plants (chillers and boilers) are critical components of a building’s infrastructure. Not only are they incredibly energy hungry, they also have the biggest impact on internal conditions when things go wrong.
So how can facility managers effectively visualise and manage the central energy plant, internal building conditions and energy efficiency all at the same time?
Inefficiency or failure of major building infrastructure like chillers or boilers can be a significant concern for any building owner:
- They are ‘energy hungry’, so small inefficiencies equal big energy waste and expense.
- Inefficient plant not only results in higher than normal energy expense, but usually goes hand-in-hand with premature wear and higher than expected maintenance costs.
- Failure of these major pieces of plant usually affects all building occupants – be ready for mass complaints from tenants when things go wrong.
- If the building is a data centre,laboratory or houses food stocks – losses into the millions of dollars can be realised in a very short time-frame.
When any of these things goes wrong, the impact for a building owner can be much higher than simply replacing or repairing
the failed piece of plant and facing angry tenants. The owner may also face loss of rent as tenants move out, loss of credibility in the market that leads to long vacancy periods and/or lower asset value or, worst of all, legal action from tenants looking to recover their losses.
Clearly, there is a need for visibility and control of major building systems so that indoor environment conditions can be controlled and tuned, energy efficiency can be managed and early intervention can be made when problems arise affecting tenant conditions.
The simplest way to do this is to implement a Building Automation System,which integrates the central energy plant with
the building’s other major plant and equipment, and takes control of all operation. If this is done well, all building subsystems will work together and provide feedback to the central energy plant to ask for more or less cooling/heating.
As an example, the system should be able to quickly highlight a simple fault such as preventing chiller operation to avoid internal building conditions warming past critical mass. An alarm can be sent to the facility manager via email, SM Soreven push notification to their mobile phone advising them to contact the site contractors immediately. Depending on the skill level of the available contractor, a fault can be fixed promptly and the chiller up and running again before the internal conditions of the building are unbearable for tenants, food stocks are spoilt or data centre downtime is caused.
While the approach outlined is a great move forward, it will only get a building halfway towards being efficient and reliable for owners and tenants. To squeeze out that other 50 percent, an integrated energy management system is required. Integrating the building automation system and the energy management system into one platform is the essence of a smart building and will allow:
- building conditions to be monitored and controlled – providing comfortable indoor conditions for tenants constant and live feedback of energy performance of major plant items constant feedback loop to the user for fine-tuning; results of control strategy changes can be seen live in energy performance feedback
- energy data that can be automatically fed back into control strategies to improve energy performance and reduce plant load – decreasing maintenance, breakdowns and downtime, and
- smart building alarming taking into account building automation and energy data to produce smarter and contextual alarms. Rather than just reporting a problem, smart alarms point the user towards resolution. This results in drastically reduced investigation time with problems fixed and plant returned to normal operation faster. For example, ‘Chilled water pump running at 100 percent, low water flow through chiller vessel with compressor cycling. Possible cause is chilled water bypass valve is stuck in open position. Most likely, faulty chilled water by pass valve actuator. Call technician to investigate.’
Nicholas Heydon is Australasian channel manager for Optergy.