The Bureau of Meteorology’s monthly reports for July 2017 show that most of Australia posted significantly above average or record warm daytime temperatures last month.
Mean temperatures – averaging out day and night time temperatures, and even in light of widespread frosts – came in as the third highest for July in records dating back to the early 1900’s. Sydney had its second-warmest July for maximums, with an average daytime top of 19.1 degrees, or 2.7 degrees above the long term average. In the city, 10 days exceeded 20 degrees during the month, or more than triple the long-term average of such days.
Significant and continuing changes to seasonal norms and patterns pose challenges for building operators, who typically manage building conditions (heating and cooling) based on static, season-specific settings on building management systems.Typical zone temperature set points for many commercial buildings in Australia is 22–22.5°C all year round, typically with narrow control bands. Such tight control potentially wastes energy because of a lack of the allowable variance in temperature that is tolerated by most occupants, especially with adaptation to increasingly off-trend winter and summer conditions. Similarly deadbands, where neither heating nor cooling operate, may be able to be widened or shifted from their traditional settings.
Buildings Alive is working with a number of commercial office building portfolio owners and operators to identify, in light of prevailing conditions, opportunities to not only save energy consumption and costs, but to ensure tenant comfort even when there are less predictable seasonal changes. Our experience suggests that not only are static, season-specific BMS and HVAC settings (such as setpoints and deadbands) increasingly problematic in ensuring tenant comfort when prevailing conditions do not align well to longer term averages, but also that the concept of optimal building energy performance needs to be revisited.
Rather than accept static settings, we are finding and realizing many opportunities with our facility manager clients and their supporting BMS and controls technicians through constant daily feedback and energy performance analysis which takes account of prevailing conditions rather than relying on operating rules of thumb or ageing historical models. In many cases, these changes have negligible effect on occupant comfort, or paradoxically allow for energy consumption to be decreased and thermal comfort to be increased at the same time. We’ve also shown with the implementation of our unique, empirically-driven building energy performance targets that a more dynamic approach is critical to understanding a building’s performance under similar weather conditions, regardless of whether they are in season or not, or whether historical patterns remain valid.
As seasonal patterns become less predictable, and temperatures fluctuate with less tendency to follow historical norms, we suggest that it is important that building owners and operators reconsider whether traditional building infrastructure operating models are really fit-for-purpose in an age where new insights can be gained on an hourly or daily basis, and energy savings made without compromising tenant comfort.