by John A. Herbert, REA
The Hong Kong Government mandates that commercial buildings owners shall engage a Registered Energy Assessor (REA) to conduct an energy audit and display the resulting EUI every ten years. Whilst many organisations are scrambling to fathom the impact of their published EUI (Mj/sqm/pa) being exposed in the public domain , others have been pleasantly shocked by the range of energy saving options, and more importantly the cost savings.
There are countless success stories, for example, the REA energy audit of a commercial building in Tsim Sha Tsui Hong Kong found HKD 75,000 per year cost saving, the implementation cost zero! On the other side of the coin, it means the building owner and tenants had wasted/overpaid HKD 825,000 and without the Government mandated audit they would probably still wasting money.
Another glorious find! Part of the tenant lighting installation on every floor of a office building was actually connected to landlord’s electricity meter, and to make matters worse the time control operated all the light fittings overnight, another easy cost saving for the landlord. Although explaining to tenant their lighting cost will increase is different issue. It must said, this is a classic commissioning failure, had the building had been properly commissioned at day one, this type of problem should have been rectified before occupancy.
Another common issue is poor maintenance, often wrapped in softer terms, for example deferred maintenance, is another easy win. A shopping centre with central chilled water installation suffered with low delta problems, that means the temperature difference between the chilled water flow and return temperature is inadequate and since energy Q = M.C.deltaT, the system fails to perform effectively.
In this case our investigation found that the AHU cooling coils were damaged and plugged with dirt, with available area for heat exchange compromised the air velocity increased and the chilled water was returned to the chiller, still cold without cooling the air. Simple, low cost coil cleaning rectified the problem, ensuring maintenance is conducted regularly is key.
Our REA provides you with an extra set of eyes and ears, on ground, reporting any deficiencies that impact energy consumption.
Will an energy audit solve every problem? No, energy audit merely identifies the problems, it is only the first step, the most important step, yes more important than the audit, is committing to the design and remedial work to optimise your energy consumption because next years utility charges will be higher than the last, and where your EUI is in the public domain, your investors, buyers, prospective tenants, and competitors already know the score.