It’s rare to find an occupied commercial building that costs what it should to run. In fact, Energy Solution Providers’ (ESP) team of experts has found only one in the 14 years since the company was founded.

Excessive energy consumption is generally the result of a disconnect between those who occupy the building and are responsible for paying the energy bills, those who manage the day-to-day running of the building and those who built it.

This disconnect is around the accountability, usage and maintenance of the building management systems (BMS). A high percentage of commercial properties use these to control the delivery of desired internal conditions, via heating, ventilation and air-conditioning (HVAC) systems.

Even when running at peak efficiency, HVAC systems are often the largest source of energy consumption for any building – when not fully optimised they can contribute to nearly 60 per cent of a building’s total energy waste. This can hit hard in terms of unnecessary energy costs, as well as creating sub-standard working conditions.

The HVAC system in one large Auckland office is starting at 2 am, although no one arrives before 7:30 am. This is due to a single incorrect setting which could be rectified in minutes.

Where it starts

The problem often starts with incomplete commissioning. It is then exacerbated by a lack of on-going maintenance and the rolling out of “quick fixes”.

 It may be safe to assume that a newly commissioned HVAC upgrade or newly completed building or refurbishment would be running optimally. However, in ESP’s experience this is often not the case. ESP has found only one building, new or otherwise, that was running optimally. Credit where it is due, that was the Department of Conservation building in Manners Street in Wellington.

There are various ways in which BMS systems contribute to higher levels of energy consumption, including:

• Heating and cooling systems fighting one another

• Plant left running when not required - due to poorly programmed automatic timers, or otherwise

• Controls which do not monitor/control what they are meant to

• Sensors either not installed or placed in the wrong position

• Maintenance of equipment and controls.

ESP has found that, on average, nearly 65 per cent of the energy consumed in schools takes place after hours, when the premises are empty and closed.

In one case, a recently opened 5 Green Star rated school was using about 130 kWh per square-metre, when energy use at a school should be closer to 50 kWh.

Billing

Further compounding the problem is the insufficient detail available as part of tenants’ monthly energy bills – particularly regarding time of use, provision of estimated or inaccurate readings, or data that only pertains to a central meter.

Billing information has improved in recent years and can be useful for tariff negotiations and bill verification.

But it still offers little of value for pinpointing areas of excess consumption. Reducing overall usage is where potential for major energy savings lies; not in reducing the price you pay for what you consume.

Without access to this level of detailed information, it is impossible to know how to best go about reducing energy expenditure or even understanding that there is the potential to do so.

For businesses in this position, the first step towards taking back control of their energy spend is to conduct a comprehensive energy audit.

The energy auditing process should enable the identification of:

• Hot spots of energy consumption, including a full comparison of energy usage during/after-hours, and of key systems generating the highest usage

• A series of recommendations for implementation, contributing to a significant reduction in the organisation’s overall energy spend.

The availability of accurate and timely energy usage data – depicting how much energy is being used, where, when and by which systems – is vital to an effective energy audit.

Armed with the insights and recommendations from this process, tenants and/or building managers can evaluate or business case potential changes or initiatives, which will positively impact their energy expenditure. This is an easy step to get organisations on the road to achieving their sustainability goals and a healthier bottom line.

Jeremy Allen is ESP's sales engineer and founder.