Most people will be familiar with the old adage: “If you can’t measure it, you can’t manage it.”
This is very true, of course. Measurement gives understanding of current performance and facilitates benchmarking against other facilities and best practice. Continuous monitoring highlights where improvement opportunities are likely to exist and provides a means to evaluate efficiency measures undertaken.
In light of this, Buildings Alive has started automatically capturing, modelling and predicting gas consumption for many of our clients’ buildings. Importantly, we relate it back to electricity use. This means building operators can target the efficiency of the whole system rather than individual parts. Already the new insights are delivering some dramatic savings, like this example recorded in Melbourne last week.
Case study – Melbourne CBD office building
Facilities managers will often schedule plant to start early during winter in an attempt to achieve comfortable conditions by the time tenants start arriving. The effect of this is illustrated in the following graphs which show a vigilantly run building where the building management system was calling on both the air handling units (AHU) (for air distribution) and the boiler plant (for heating the cold air) at around 6 am. Unfortunately, when the AHUs started up, cold air from the outside would also be distributed throughout the building – cooling it down even further.
So the boilers had to work hard to heat up the building as well as the cold air being sucked in from outside. This was driving both the electricity and gas consumption higher – but nobody really understood by how much. On the occasion illustrated below, electricity demand reached as high as 900kW and the demand for gas energy reached 6000MJ for one 15 minute interval.
Date: Wednesday 22nd July 2015
Buildings Alive’s REF highlighted the effect that simulataneous start times were having on electricity and gas demand, which encouraged the building’s managers to trial changes to the schedules, keeping in mind that they would see the effect directly in the next day’s message. So they decided to start the boilers slightly earlier (around 5am) and keep the air distribution to the building shut off until the boilers heated up. Then the AHUs were started around 6am to distribute only the heated air throughout the building.
The immediate effect was a drop in peak gas usage from 6000MJ to 4,500MJ and a reduction of 50kW in electricity demand, even despite the morning being considerably colder than the previous day. The next day’s message presented the positive effect of the change in operation.
Date: Thursday 23rd July 2015
A clever initiative rewarded with a great result for the occupants, the environment and the building owner’s bottom line!