Energy efficient design opportunities lost
Often you don’t even need to go inside a building to see opportunities for energy conservation in Hong Kong. Sadly this opportunity (refer photograph) was many lost years ago at design stage when the lighting control strategy was planned and conceived.
Perhaps it is not clear from the photograph, I took this photo on a glorious sunny morning yet the unneeded halogen incandescent fittings burned bright, serving no useful purpose except burn extra carbon.
And that is the reason why independent third party energy consultants review projects, to highlight these opportunities before the die is cast.
Kelcroft E&M Limited
helping lower the cost and impact of doing business in Asia
1.00 pm, Sunday, 18 January 2008, Kowloon Bay, Hong Kong
It is a beautiful bright sunny Sunday afternoon, the store is obviously closed, and the shutters are down. Yet all seven (7) exterior lamps are burning brightly, here is a photograph captured with my camera phone.
Did the owner forget? or believe it would not make a big difference? Did someone consider the extra coal that would be burnt at the power station and its resultant pollution to keep those lights on?
This raises the thorny issue, the true cost of power, can we continue to overlook the generation externalities? The social cost of pollution created by power generation in Hong Kong is presently estimated to be in the order of HK$ 6 billon (US$ 740 million) per year, but that cost is not priced into the consumers energy charge, its paid by the tax payers. The Hong Kong Government verbally advocates a polluters pay policy, however the reality is very different, often relying on the tax payer to foot the bill.
Continuing the lighting audit theme for another post – A simple but often overlooked option for controlling energy costs is thoughtful design of the lighting circuitry and control system for lighting, particularly exterior lighting.
Exterior lighting control is hardly rocket science, low cost circuitry with a contactor and photocell is a preventative measure, keeping the the external lighting from operating during bright day time hours saving countless kilowatts, and the maintenance cost for re-lamping.
Unfortunately, as the exterior area of the car park as the photograph indicates, poor design coupled with lowest first cost mentality means building owners often end up with only one control circuit operating both indoor and outdoor fittings simultaneously. Of course, this causes waste due to the unnecessary operation of lights during the day light hours.
It is easy to zone other areas too, in the car park example, covered parking having a perimeter with abundant natural light don’t need electric lamps burning during daytime hours.
If you opt for photocell control, do ensure the photocell location is accessible for easy cleaning.
It is not just about the recording lighting level (known as LUX)
Lighting efficacy – Energy audits for buildings, typically include a lighting audit. But just recording the lighting level (known as the lux level) in the various rooms is not enough. We need to assess the effectiveness of the installation.
During a recent energy audit several lighting fittings (as shown in the photograph) were discovered. Perhaps discovered is the wrong word, the high intensity fittings were plainly obvious.
Pairs of uplighting fittings were installed close to each other, and very close to the ceiling.
These fittings didn’t add any value to the illumination of the space, as you can clearly see these intended uplighters only created an intense, localised pool of light (and heat).
Based on operating 3,600 hours per year, each fitting wastes HK$ 660 per year in electricity. Just measuring the lighting level is not sufficient for an energy audit, in this case immediate removal was recommended saving electricity.
Also remember that in air conditioned rooms removing lighting fittings not only lowers the electricity consumption for lighting, it also lowers the heat gain which in turn reduces the load on the air conditioning system. As a rule of thumb, eliminting 1 Kw of lighting lowers the total electricity consumption by 1.3 kw.