As we’ve written about before, buildings can be fickle things when it comes to managing their energy performance. The average commercial property has a large number of systems consuming power, and these can and do misbehave, sometimes through gradual degradation of the systems themselves, and sometimes, such as in today’s tale, through human intervention. As a wise facility manager once said, his building would perform beautifully…if only it were empty. He could be on to something.
The story begins with a Greensense client who has been using our software to monitor energy performance across their Australian portfolio. Here’s how things unfolded:
- On Friday October 7th a Minimum Daily Demand (MDD) alert was triggered in the Greensense software and sent to the client’s energy manager based at head office. The energy manager had configured an alert to track MDD (or baseload, if you prefer), with the alert set to fire if MDD exceeded the minimum demand from the previous month. MDD had increased to 50kW from the normal baseline of around 20kW, as you can see in the screenshot below.
- After discussion with the site manager, it wasn’t immediately obvious that anything had changed at the property, so the client arranged for one of our energy engineers to make a visit.
- On Thursday October 13th our engineer visited site. Given the major electrical loads in the building were HVAC and lighting, he started his investigations with HVAC first and immediately discovered part of the HVAC system running in test mode i.e. running continuously, 24/7. On further investigation, it turned out that the HVAC maintenance contractor had serviced the unit on October 6th and accidentally left it in test mode after completing the service. Our engineer corrected the problem, and energy consumption at the site immediately returned to normal levels.
The chart above shows how the problem played out in the data. Click the image to zoom.
Over the 7 days of the event, from the time the HVAC contractor left the unit in test mode to the time it was remedied, an additional 6,100 kWh of energy was consumed, equating to an average daily increase of around 38%. Had this issue gone undetected, which, with the absence of suitable tools to monitor site performance it may well have, this would have added an extra $1,250 per month (or around 12%), to the energy bill for the site.
Issues like the one described in this post occur in buildings every day, but mostly go undetected. Without some technology smarts to spot issues as they crop up, often the only opportunity organisations have to pick up these problems will be when they pay the bill at the end of the month. It takes a very switched-on accounts team to notice relatively subtle changes in energy spend, particularly across a portfolio of sites, and then to notify the relevant people.
It is also a reminder that there are things happening in buildings all the time that can materially impact building energy performance – in this example the regular maintenance check of the HVAC plant. It’s important to understand what changes are taking place and when, even if it’s not immediately obvious that they may effect energy use. Building managers (and their CFOs) run the risk of being unpleasantly surprised if they don’t.