Tag Archives: emission

Hong Kong’s air quality getting worse

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Air pollution levels in Hong Kong were the worst ever last year, the South China Morning Post reported on January 10, a finding that may further undermine the city’s role as an Asian financial center as business executives relocate because of health concerns.

Worsening air quality in Hong Kong caused by vehicle emissions and industrial pollution from the neighboring Pearl River Delta is already forcing many in the financial community to move to Singapore.

Readings at three roadside monitoring stations in Hong Kong’s Central, Causeway Bay and Mong Kok commercial districts showed that pollution levels were above the 100 mark more than 20 per cent of the time, the newspaper said, citing the city’s Environmental Protection Department.

This was 10 times worse than in 2005, when very high readings were recorded only two per cent of the time, it said. The station in Central business district, home to the Asia head- quarters of global banks such as HSBC Holdings Plc and Goldman Sachs Group Inc, showed the worst figures, with excessive readings a quarter of the time, the report said. Hourly readings are taken at the roadside stations throughout the year on major pollutants such as respirable suspended particles and nitrogen oxides. A reading above 100 means at least one pollutant fails air quality objectives.        hongkong-air-pollution

Environmentalists renewed their calls for the immediate introduction of new air quality objectives, claiming that the government had deliberately delayed their introduction to ease the way for major infrastructure projects, the newspaper said.

The department blamed the figures on unfavorable weather conditions, worsening background, pollution and the number of aging vehicles on streets. The newspaper quoted the government as saying a number of measures were being considered to help improve air quality, and new air quality objectives would be discussed by Hong Kong’s legislature soon.

Straw as Building Material for Future

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A modern take on straw-bale construction may well be the grand design of the future if results coming out of the University of Bath are accepted by the construction industry. Think of a straw-bale house and you might imagine a tumbledown shack that leaks, creaks, slumps and smells somewhat of the farmyard. But step into Bale-Haus, a startlingly contemporary looking prototype home that has been built on the Bath Campus and there’s nary a wisp of straw to be seen. Instead, you are in a hallway of an upside down house with two bedrooms and a bathroom on the ground floor and an airy open plan living area upstairs. It feels like a little piece of Scandinavia has just arrived in Somerset, southwest England. The straw bales are all packed tightly inside a series of prefabricated rectangular wooden wall frames, which are then lime rendered, dried and finally slotted together like giant Lego pieces called ModCell panels.

People perceive straw houses as being a bit hippy and not particularly durable. Add to that the problems of getting mortgage – very few lenders will consider straw-bale construction. The benefits of straw, points out Professor Peter Walker, director of the University of Bath’s BRE Centre for Innovative Construction Materials, are that “it’s cheap, widely available and a good insulator. It’s been used in buildings houses for hundreds of years”.

The stack that remains after grain has been harvested – straw also helpfully soaks up carbon from the atmosphere and locks it in, so long as it is not allowed to decompose. For the building industry, which currently depends on materials with very high embedded energy costs -  concrete and brick are expensive in carbon terms both to make and to transport – straw could therefore offer a welcome solution to housing’s greenhouse gas emission.

The straw-bale house won’t get sopping wet in a thunderstorm or go up in a whoosh of flames if you knock over a candle. The results now being published by Walker and his research partner, Dr Katharine Beadle, who have spent the past 18 months testing the BaleHaus against an exhaustive list of risk factors that could rot it, burn it or blow it down, so far seem to be reassuring.

Beadle with his team took a ModCell unit to a test laboratory and tried to reduce it to ashes by strapping it to a fiery furnace and raising the temperature to over 1,000 degree Celsius. “It’s standard test to replicate a fire in a building.” explains Walker. “It means you know that a house will at least retain its structural integrity for half an hour, which gives people a chance to get out”. “It took an hour and a half of being in direct contact with the flames”, says Beadle, before the lime render began to drop off, “and then the straw did start to burn back, but because it’s so compacted it suffered more charring then actual disintegration.”

When it come to blowing the house down – hydraulic jacks were placed against the walls to replicate wind forces pushing against the bales – the ModCell panels moved a few millimeters, but stayed within the tolerances allowed for by the computer modeling carried out prior to its construction. That says Walker, could be very good news for the price of the eventual ModCell building system. “It means the house is stiffer than it needs to be.” The approximate cost of the current modular building system for this design is £132,000 from above the concrete slab. “Cost is a challenge to the introduction of this technology but as a prototype house I think it stacks up well,” said Walker. “The aspiration is that it should be cost competitive with more savings coming through reduced heating bills.”

To replicate the heat given off by humans and appliances arrays of incandescent light bulbs on timers blaze in every room at pre-programmed times of day “to see how much heat escapes, and what level of heating would be needed at different times of the year,” explains Beadle.

“That environmental modeling will give us all the numbers about the energy the house is predicted to use. And if we are predicting how it will operate in given climate change, we can then put in those variables.”

Sensors embedded within each wall panel constantly monitor the degree of moisture absorbed and then released back through the breathable lime render into the sir outside by the panels. And on the air tightness test that was carried out, BaleHaus came in way under the building regulations threshold, and did considerably better than the far lowest “best practice” standard.

- The Guardian