Friday, February 20, 2015

how families waste electricity, recycling of used water

Do you know that much of the electricity used in homes is wasted because of faulty practices and our choice of gadgets? Award-winning energy consultant and expert on water efficiency and green business U. V. Krishna Mohan Rao says it’s possible to drastically reduce our electricity consumption by adopting a few simple measures. Rao’s family of six living in Viswa Syamalam, spread over 2,000 sq.ft., consumes only 100 units of electricity a month. His firm, U. V. Krishna Mohan Rao Associates, charges customers a fee based on the energy savings they achieve. Excerpts from an interview:
What are the common mistakes we make that lead to electricity wastage?
One of the common mistakes is turning off appliances using the remote, which leads to significant loss of ‘stand-by’ power. 1-5 per cent of the electricity consumed by the appliance when in use, continues to get consumed by it even when it is turned off using the remote. Placing warm/hot food in the refrigerator is another mistake. We should pump water into the overhead tank during non-peak hours (6 to 10 p.m. in many states), which ensures better efficiency as the quality of power received then is better.
Do electrical appliances that are plugged in even after turning off the power source lead to power wastage?
No, this does not cause any electricity drainage. It’s a myth that appliances that are plugged in to the power source cause wastage.
How can we minimise electricity consumption when using air-conditioners?
Use air-conditioners in combination with a ceiling/wall/pedestal fan and set the AC temperature at 27 degrees. This will give you the same cooling comfort as you would get when you set the temperature between 18 and 22 degrees. Opt for moderate cooling as air-conditioners are not meant to chill the room and necessitate the use of blankets. Remove redundant material/furniture from the room as electricity gets spent on cooling it.
What lighting fixtures can we use that will help conserve energy?
The entire home can be made to receive ample natural light throughout the day by channelling in sunlight through large windows, light pipes, extra windows at higher levels, etc. For the night, use LED lights that consume just a fraction of electricity as compared to CFLs/fluorescent tube lights. Painting walls in white or pastel shades enhances lighting and minimises heat absorption from sunlight.
Does minimising electricity consumption necessarily involve high initial costs?
If done during the construction stage, it may cost less. Redundant investments on voltage stabilisers, unnecessary wiring, etc, can be avoided. Retrofitting can be done at a later date, considering the recurring operating expenditure.
What should we keep in mind while buying gadgets?
Use only star-rated and super-efficient appliances. Ask about ‘stand-by’ power consumption details. Choose appliances that can run on wide voltage variations (160 V to 240 V) without the need for external stabilisers as stabilisers consume between 1 and 5 per cent of the electricity they draw in. If you have to use a stabiliser, locate it outside the air-conditioned room, as stabilisers generate heat. For hot water, use solar-thermal heaters, not electric geysers. For daily washing purposes, do not turn on the heater in the washing machine.
Use a three-compartment overhead tank to treat greywater. Indukanth Ragade tells us how
In the earlier article, we discussed how water used for bathing and washing clothes can be treated by water-loving plants and allowed to percolate into the soil to augment the shallow water table. This concept can be used in individual houses. In apartment complexes, a large volume of greywater is generated and can be recovered for flushing, gardening and the excess water can be sent back into the soil. For this, a bathtub-like cemented structure has to be built with a sloping bottom with an outlet at the lowest point. A layer of blue metal is laid at the bottom with a small layer of sand over it, followed by another layer of garden soil. The Canna indica (Indian shot) is planted on the soil and a small inspection tank is provided alongside. The blue metal layer enables the treated water to freely flow out of the tank. The sandy layer prevents the soil from clogging the blue metal, while the soil layer cleans the water. The bottom can either be cemented or covered with a double layer of empty cement bags.
To utilise this water, we have to provide a three-compartment overhead tank (OHT). Builders generally provide a two-compartment OHT, one to hold potable water and the other to hold water for non-potable purposes. However, the potable water accounts for only 10-15 per cent of our total water usage and providing 50 per cent capacity for it is not necessary. Instead, a three-compartment OHT can be built in the same space that stores water for flushing, drinking and other purposes. By simply closing the two valves interconnecting the three compartments, we will be able to store three different qualities of water and use them for specific purposes.
In such an OHT, the treated greywater can be safely stored and used exclusively for flushing. Alternately, by closing one of the two interconnecting valves, two kinds of water can be stored and used appropriately. In such complexes, advance planning for recycling can be done by providing additional gullies for diversion of the greywater to the soil bed and connecting them with the normal gully through elbows and pipe pieces without applying any gum so that they can be disconnected whenever necessary and the greywater can be allowed to go into the regular internal sewage line.
This recycling method can be fully or partially decentralised wherein some of the greywater is cleaned and allowed to seep down to charge the shallow water table and the rest is treated and used for flushing and gardening.
Chennai-ites do not realise that in most parts of the city, the soil is suitable for traditional shallow dug wells. If such wells are provided, people will be able to enjoy greater water security as shallow wells generally yield good quality water, can be easily charged with terrace rain water and the excess water, not needed for flushing, can be treated and routed back to the soil.
This is the final of a three-part series on greywater recycling. For details, mail isragade@yahoo.com             http://www.thehindu.com/features/homes-and-gardens/green-living/grey-to-gold/article6916432.ece

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