Saturday, July 21, 2012

The Air Con

In the United States, consumption of energy for air-conditioning homes and vehicles has more than doubled just since the mid-1990s. In India, total consumption for air-conditioning is projected to climb as much as ten-fold over the coming decade; air-conditioners already reportedly account for a staggering 40 per cent of all electricity consumption in the city of Mumbai. In Brazil, air-conditioning demand has more than tripled in just five years, contributing to a surge in electricity consumption. Unusually steep increases in electricity demand in southern European countries are being blamed on the proliferation of air-conditioning. The greatest irony, of course, is that by chilling the indoor environment today, we are helping ensure that future summers will be even hotter. Turning buildings into refrigerators burns fossil fuels, which emits greenhouse gases, which raises global temperatures, which creates a need for -- you guessed it -- more air-conditioning. Air-conditioning's massive energy demand is overwhelming efforts to reduce greenhouse gas emissions. This isn't smart.

Take the output from all of the United States’ renewable electricity sources combined, multiply it by five, and it still could not satisfy current air-conditioning demand - let alone serve other uses. The US department of energy projects that wind, solar, geothermal, and biomass electricity generation will indeed expand almost fivefold, but not until 2030. By that year, if the department's predictions hold, total electrical generation from all renewable sources will be sufficient to satisfy only 75 per cent of air-conditioning demand. For everything else, there will be no green alternative.

 Energy consumption is not the only issue. The cool, still, dry atmosphere of the standard home or office has a variety of other unpleasant and sometimes hazardous side effects. Obviously, air-conditioning can play an important role during killer heat waves. But keeping vulnerable members of our communities alive during heat emergencies is one thing; using that as an excuse for neglecting horrible urban living conditions while at the same time tolerating the routine, lavish deployment of chilled air throughout much of the rest of society is another. Well-insulated buildings often suffer from so-called sick building syndrome. Depending on the extent of outside ventilation, toxins and irritants can be ten to 100 times as concentrated in indoor air as they are outdoors. Researchers in Brazil, the United States, and Europe have found that people who are employed in air-conditioned workplaces visit doctors and hospitals more frequently and generally have a higher risk of poor health than do those who work without air-conditioning. Under natural ventilation, people have been found to experience fewer problems with headaches, colds, other respiratory ailments, circulation problems, eye dryness, allergies, and chest tightness. There is lower absenteeism when employees work near windows and can open them. 

In a world without air con and capitalism, a more flexible, more relaxed workplace helps make summer a more pleasant time, offices close, working hours are reduced. Daily afternoon siestas. Yet for capitalists all the see is slower workdays mean less productivity, shorter hours and closed offices mean lost profits for employers. Socialists envisage more people spending more time outdoors -- particularly in the late afternoon and evening, when temperatures fall more quickly outside than they do inside -- neighborhoods see a boom in spontaneous summertime socializing. Rather than cowering alone in chilly home-entertainment rooms, neighbors get to know one another.

 New construction style such as high ceilings, better cross-ventilation, whole-house fans, screened porches, basements and white "cool roofs" to reflect solar rays.  "Green roofs" of grass, ivy and even food crops sprout on the flat tops of government and commercial buildings around the city, including the White House. These layers of soil and vegetation (on top of a crucially leak-proof surface) insulate interiors from the pounding sun, while water from the plants' leaves provides evaporative cooling. More trees than ever appear in both private and public spaces.

1 comment:

ARS (Architectural Refinishing Services) said...

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