A Change in Management
With HVAC typically accounting for 60-70% of base building energy consumption, there’s no escaping the reality that to maintain a NABERS rating, it’s critical to maintain HVAC at optimal efficiency levels. Reinforcing the critical value of HVAC maintenance, recent IPD data shows a clear difference in annual returns for buildings above and below the 4 star NABERS mark
Energy management software solution [that] predicts and optimises energy usage is producing results of between 10-25% energy reduction in commercial buildings where [BuildingIQ] is installed
In contrast to the Green Star rating, which is awarded once and can be achieved by paying a premium during the design and construction stages, NABERS is a performance based rating scheme based on carbon emissions. Performance of a building can change over time, subject to many variables such as HVAC settings and service, tenant occupancy and behaviours, and weather.
When building energy usage varies upwards significantly, even for just one month, it can affect the cumulative consumption across a year and result in a lower NABERS rating. This can often take up to 12 months to get back up again, resulting in lower annual returns for the building. It’s becoming more apparent that a ‘set and forget’ approach now carries the potential for a significant financial penalty.
Aligning expectation with reality
Because NABERS ratings are based on performance, it’s critical when commissioning a HVAC retrofit or building refurbishment to model expectation as closely as possible to how a system will perform in the real world. Expectations are informed by an understanding of how the building operates using energy consumptions modelling, historical data and also assumption, such as future vacancy rates. Whereas reality is driven by other factors, such as the behaviour of occupants, the weather, the efficiency of equipment and many other variables – even where the building contractor places the thermostat.
At AE Smith, we’ve developed a new approach in order to identify the risks that exist to more closely align expectation and reality. These include modern risk assessment, automated BMS, automated energy alarming, and alternative maintenance practices that leverage online technologies for ongoing system monitoring and system optimisation.
Modern risk assessment
Building Information Modelling (BIM) software such as Dynamic Thermal Modelling can be used to create accurate simulations of energy use. By incorporating past energy bills and weather data, models are calibrated to closely match actual consumption, including any inefficiencies in an existing system. Through this process the accurate baseline that is obtained can be used to confidently simulate virtually any upgrade imaginable.
BMS and energy alarming
Through coupling building management and energy reporting systems the data obtained through building sensors is used in real time to optimise the Building Management System (BMS) operation. Adding forecasted weather data to this information/feedback loop further fine tunes building operations and minimises energy consumption.
Adaptive temperature control algorithms, based on seasonal ambient temperatures trigger gradual changes in building temperature set points over the course of the year. This keeps tenants comfortable and reduces the risk of individual tenants adjusting HVAC settings, or compensating with additional equipment.
Automated alarms are integrated into the system to alert the Facility Manager and off-site service team of any unusual variations in building, equipment or energy supply behaviours.
Implementing these new age energy management practices is becoming increasingly easy to achieve. BuildingIQ, a leading energy management software solution predicts and optimises energy usage with all data variables compiled in a cloud based dynamic model. The BuildingIQ system is producing results of between 10-25% energy reduction in commercial buildings where it is installed.
The barrier to entry to install a solution like BuildingIQ has been removed with no mechanical infrastructure upgrades or upfront capital expenditure required. Smart customers use a portion of the savings generated through reduced energy use to pay for the BuildingIQ software subscription.
Condition Based Maintenance – a revolution in building management
Planned preventative maintenance has been around since the beginning of the industrial revolution. As with many industries, technology has enabled a better way.
In response to the greater amounts of data and more powerful reporting and management tools now available, we now react to the building information itself to inform servicing and adjustments to the system. This is called Condition Based Maintenance.
This includes remote monitoring of system performance and even rectification of some issues from off-site. Accurate and immediate identification of mechanical faults informs immediate dispatch of the right technicians with the right information and the right spare parts. On some occasions, the off-site service team has become aware of an issue before the Facility Manager has.
Well measured equals well managed
The old adage, what you can measure, you can manage is entirely valid when retrofitting buildings. With all this data informing modelling, as well as alarms and the integration of BMS and energy systems, it’s absolutely possible to stay on top of a building’s performance in real-time. With a secure NABERS rating, a building owner can now ensure ongoing returns.
For more information please contact David Odd on 1300 313 313.
[This article first appeared in Retrofit Australia magazine, Vol 3 No 1, 2014, titled, “The biggest change in building management since the industrial revolution.”]