Text by Kyle Gray
Source: This article was taken from the May 2011 issue of Real Estate Investor
Sustainable solutions for the future
Depending on the environment, a man can survive between two to seven days maximum without water, he can survive more than a month without food. Water is our most precious resource, a blue gold, often taken for granted in certain parts of the world and prayed for in others. Not only are we facing an energy crisis, but a water crisis as well. According to the World Water Councils latest survey, 1.1 billion people are currently living without clean drinking water, while another 2.6 billion lack adequate sanitation.
By the year 2050, some 4 billion people (that’s over half of the entire world’s population) will be facing severe water shortages. Some speculate that the next war shall be fought over water, as wars in the past have been fought over land, resources and now oil.
This is not a far-fetched scenario from a science fiction movie. Instead, this information comes from NASA, the World Health Organization (WHO) and other agencies worldwide. When you consider the facts, it’s not hard to understand why there is a problem.
As we can see there is a lot of work to be done, but firstly there needs to be a change in perception and the creation of awareness. Internationally there have been strategic measures implemented to rectify this process. Locally our government in partnership with Eskom has started implementing measures that can steer us in the right direction.
Hot water management
Commercial properties with facilities that have major hot water demands, such as kitchens, multiple ablutions, laundries etc. Can save as much as 40 – 60% of their energy costs by adopting more efficient water heating processes, and by reducing their consumption of hot water. Solar water heaters and heat pumps are both recommended by Eskom, as energy-efficient alternatives to water heating using a conventional electric geyser.
Eskom has launched a Solar Water Heating Rebate Program to encourage the public to participate in the use of renewable energy. Eskom’s objective with this program is to decrease the demand on the already overloaded electrical grid. They have set qualifying criteria for installers, suppliers and products.
What are the solutions?
The idea is to try and implement solutions that will be both cost effective in the long run, but can also save on the use of electricity, save and recycle water (know as grey water recycling) or hopefully both. Water and wastewater facilities can upgrade their heating, cooling, and ventilation systems to improve energy efficiency and save money while keeping the work environment comfortable.
Heat pumps
Currently, most commercial enterprises, particularly those with major hot water demands for kitchens, laundries, restaurants, ablution facilities and industrial processes heat their water with geysers and steam cylinders called calorifiers. An important technology that is simple and effective in lowering electricity usage is the deployment of heat pumps. Heat pumps offer major consumers of electricity a significant opportunity to reduce costs related to water heating.
A heat pump can save up to 66% of energy consumption and, in some circumstances, even more than that. In effect, heat pumps transfer heat from a source such as air or water, to the water that is to be heated. Heat pumps use the reverse cycle of a refrigeration utility to heat water. A heat pump can be up to three to four times more efficient than a hot water system, which is powered by a normal resistance element. For every kW of electricity supplied to the heat pump, more than three kW of thermal energy in the form of hot water is produced. A thermostat keeps the hot water at a constant temperature between 55 and 65 degC, with 60 degC being the most commonly used setting.
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The facts
- The world’s population tripled in the 20th century, and is expected to increase by another 40%-50% percent in the next 50 years
- The use of renewable water resources has grown six-fold
- There is no more fresh water in the world today than there was 1 million years ago
- Water cannot be replaced such as alternative fuel sources can replace petroleum
- It is almost guaranteed that, once water supplies become even scarcer, conflict will break out across the globe
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Built-environment professionals have an obligation to design towards sustainability
An additional benefit, which is often used to increase the economic benefits of a heat pump, is that of the cooling cycle, which can be utilised to simultaneously cool a portion of or an entire building. This is especially useful in the hospitality industry where cool air can be channelled into lobby areas, thus saving on the cost of a separate stand-alone air conditioning system. Heat pumps are typically mounted on the outside walls of buildings under the eaves or at ground level depending on the configuration of the system.
Grey water recycling
“Modern technologies today allow us to break new ground in environmental protection. The future lies in finding a sensible combination of technological solutions to environmental problems,” explains Michael Hasenbeck, Managing Director of Pontos GmbH. The company was founded in 2001 and specialises in the reuse of valuable resources such as water and energy from the wastewater off baths and showers. It all began with the question of why precious drinking water, of all things, should be used for flushing toilets, for cleaning and for watering green spaces. Grey water composes 50-80% of residential wastewater generated from all of the house’s sanitation equipment (except toilets). The solution is water recycling – after showering or bathing, the cleaned and reprocessed water is then used for flushing toilets, cleaning or watering gardens and green spaces.
A heat pump can save up to 66% of energy consumption and, in some circumstances, even more than that
Shower heads and water flow regulators
Many large buildings include ablution facilities for workers where multiple showers consume large volumes of hot water on a daily basis. Together with solar water heating or heat pumps, one very effective way to reduce this drain on resources is to fit energy and water saving shower heads or water flow regulators. Facility managers should use the services of an accredited plumber when retrofitting showers, because factors such as water pressure will influence what products are most suitable.
Making a difference
The ecological design, efficient performance, and minimisation of the overall life cycle impact of buildings in southern Africa are critically important to the sustainable development of the region. Cooling buildings requires several times more energy than heating and in spite of relatively high rainfall; water remains a scarce resource in South Africa. Built-environment professionals have an obligation to design towards sustainability and building owners and operators are commercially motivated to learn about and strive towards high levels of performance in their buildings.
RESOURCES
Eskom
www.eskom.co.za
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