- Broker Directory
- My Tools
- News & Advice
- Market Trends
- Other GN Sites
Can you simply walk into a building and know whether it is energy-inefficient? Even better — can you figure out the same just by looking at its outside? This question applies to any kind of building, be it commercial, residential, mixed-use, or even a villa, hospital, airport or school. And if we do realise that a building is energy-inefficient, is it possible to know its degree of inefficiency?
The answer to all the questions is yes. When stepping inside a building, one can watch out for telltale signs of inefficiency. Looking at things from the outside, one can actually find, as my MBA friends love to say, data-based objective evidence of not only inefficiency but also the extent of it.
In order to find the fundamental sources and causes of energy inefficiencies, one must understand that energy inefficiency or wastage is often due to one or more of several specific factors. These include over-sized electro-mechanical equipment, an absence of sufficient controls, inappropriate usage, application of outdated technology and, most importantly, human carelessness. Energy inefficiency in buildings can be easily found using these indicators.
What to look for
The first, foremost and most common sign happens to be the easiest to spot. How many times have we walked into a building during peak summer and instantaneously felt that we will freeze or catch a cold?
An old joke is that in the UAE one wears a jacket more often indoors than outdoors. Carrying sweaters to the office and hoodies to school, even during summer, has become an accepted norm. Facilities in such buildings have been over-designed and heating, ventilation and air conditioning (HVAC) equipment are operating without adequate controls which results in over-cooling. This consumes excessive energies as well as make the indoor environments uncomfortable.
How do we judge the degree of inefficiency? From the experience of implementing energy conservation programmes in more than 200 buildings, I can say that most use at least 15–30 per cent more than the required energy for operating their facilities in an energy-efficient manner.
And how about diagnosing a building from looking at its outside? Transport in the UAE is largely car-based, with most people driving back from work to home in the evenings. It is an old habit of mine that every time I am stuck in traffic, I tend to stare at the beautiful high-rises all around me. I have often wondered why practically all the lights in an office building are burning bright in the late evenings, even past 8 or 9pm. This is apparently necessary because a few cleaners are at work in these offices.
That almost all lights are left on across many floors for several hours after work, just for the requirement of a few cleaners evidences several kinds of inefficiency. These range from a lack of adequate controls that could enable only the necessary lighting to be used for the cleaners, to carelessness that necessitates all lights to be kept on even when the cleaners aren’t working on a floor.
Next time you take a dhow cruise at the Dubai Creek, look out for the towers at Deira. You will find only one building with almost all its lights switched off in the evening. This is the Dubai Chamber office, which is the first in the Arab world to achieve Leed (Leadership in Energy and Environmental Design) status. Hundreds of lighting fixtures can be found glowing in the car parks of major shopping malls through the day, when they should be left off.
How about residential facilities? Although the visible signs are not as remarkable in villas, one would still come across some that have lights on their boundary walls switched on even during the day.
Some other obvious signs are inability to control temperatures inside offices due to a lack of sufficient and rightly located thermostats, an inadequate number of light switches in open-plan offices, windows that are left open in peak summer to counter the over-cooling of AC systems, escalators operating when there is no one to use them, car park fans running 24x7 and innumerable light fixtures on the ceiling where just one-tenth would have sufficed.
While these telltale signs are generally the best indicators of energy-inefficient facilities, these are no more detailed than the equivalent of a pulse rate or BP check on the human body. Both are preliminary indicators that do not detail the full extent of the problem, unless one is an energy efficiency specialist. Some of the best ways to check the potential level of inefficiencies can be applied universally in the UAE to all types of facilities, ranging from high-rises to villas. The exercises below can engage adults and children alike and help instill awareness of energy efficiency.
Add up the total wattage of all the indoor lighting fixtures at the place in question and divide by the total built-up area in square feet. If you get a figure of less than 0.90 watts per square foot at your office, it has been well designed for energy efficiency. For villas or apartments, this number should be below 0.61 in order for it to be energy-efficient and for schools or universities it should be below 0.99.
Typically, facilities in the UAE are several times overdesigned and without an adequate number of controls. Of course, energy-efficient design does not always translate into energy-efficient management and vice versa.
A similar exercise can be applied to the HVAC system. Sum up the total tonnage of all the installed systems. Divide the built-up area by the total tonnage and if you arrive at a figure of 400 square feet per tonnage of AC or more, your facility is extremely well designed for energy efficiency.
While the above-mentioned lighting power densities are derived from the energy efficiency standards of the American Society of Heating Refrigeration and Air-Conditioning Engineers, the HVAC benchmark is derived from my personal experience of working on buildings in the UAE to reduce their energy consumptions.
Last but not least, perhaps the best method to measure a facility’s energy efficiency is to measure its energy consumption in kWh (kilo Watt hours) on a hourly basis across all seven days of a week. For offices, the energy consumption over weekends and nights should not exceed more than 20–30 per cent of that during working hours on weekdays.
For residential units, it would be the other way around. The larger the variation between the energy consumption of unoccupied hours as compared to occupied hours, the more actively the facility is being managed for energy efficiency. This is an easy exercise in villas, where one can read the energy meter located outside and plot some interesting graphics.
While this article is by no means a comprehensive guide to detecting energy inefficiencies, which is the first step in the journey towards reducing utility consumptions, it should provide you with some high-level guidelines towards getting a pulse of your facility, whatever its nature of use. And watch out for children in hoodies streaming out of a school on a September afternoon. The school is almost certainly energy-inefficient.
Source: Sougata Nandi, Special to Property Weekly
Over 17 years, his work has helped reduce carbon emissions in excess of more than 200,000 tonnes. He was instrumental in accelerating an ICT-based energy efficiency programme in 2011 that continues to reduce carbon emissions by more than 5,000 tonnes a month across nearly 100 buildings. An alumnus of the Indian Institute of Technology, he has developed and implemented the region’s first Sustainable Development Policy for a diversified free zone operator in Dubai. He has implemented numerous energy and water conservation projects across the UAE and his work has won him and his organisations several awards in recent years, including the prestigious Emirates Energy Award multiple times
Al Nisr Publishing accepts no liability for the views or opinions expressed in this column, or for the consequences of any actions taken on the basis of the information provided.