Tag: 杭州龙凤夜生活

Resilient Design: Natural Cooling

first_imgAlex is founder of BuildingGreen, Inc. and executive editor of Environmental Building News. To keep up with his latest articles and musings, you can sign up for his Twitter feed. Over the past month and a half, my blogs been focusing on resilient design — which will become all the more important in this age of climate change. Achieving resilience in homes not only involves keeping them comfortable in the winter months through lots of insulation and some passive solar gain (which I’ve covered in the previous two blogs), it also involves keeping them from getting too hot in the summer months if we lose power and our air conditioning systems stop working. This week, despite the freezing weather, we’ll look at cooling-load-avoidance strategies and natural ventilation.Orientation and building geometryWith new houses, we can relatively easily control orientation and geometrical form to minimize unwanted solar gain.The optimal orientation for a house is with the long axis running east-west, so that the longer walls face south and north. This allows the house to benefit from the sun when we want that heat, but keep it out when we don’t want it.The sun always rises in the east and sets in the west, but in the summer it rises much higher in the sky. By having more windows facing south, most of the sunlight will glance off that glass during the summer when the sun high overhead, while in the winter, with the lower-angle sunlight, most of that sunlight shines through those windows — providing passive solar heating (see last week’s blog).At the same time, having fewer windows on the east and west makes sense relative to summertime overheating. Significantly more sunlight shines through a square foot of east- or west-facing window during the course of a day in the summer than through a square foot of south- or north-facing window, so limiting east and west windows helps to prevent overheating.Window selectionThe type of glazing in our windows has a major impact on how much sunlight is transmitted through them. This is why it almost always makes sense in well-insulated buildings to “tune” the windows by orientation. By this, I mean using glass (glazing) on the south that transmits a high percentage of the sunlight striking it and glass on the east and west that transmits less sunlight. We refer to this property as the solar heat gain coefficient (SHGC); it is the fraction of total solar energy transmitted through the glass (assuming the sunlight strikes the glass at a normal (perpendicular) angle.A good rule of thumb is to select south-facing windows that have SHGC values of 0.6 or higher (0.5 or higher with triple-glazed windows), and east- and west-facing windows with SHGC values of 0.3 or lower.Windows with SHGC values of 0.6 will transmit twice as much solar energy as windows with SHGC values of 0.3. The beauty of recent advances in glazings it that we can now have fairly large window areas (to provide views and natural lighting) without nearly the energy penalty (both from heat loss and unwanted solar gain) we had two or three decades ago.Shading windows from direct sunOn the south, we can also use simple overhangs or awnings to block virtually all of the direct sun. On the east and west, different shading strategies are better, because the sun is lower in the sky. For these windows, exterior shade screens or roller blinds can be very effective. So can plantings of tall annuals like hollyhocks or vines like clematis, morning glory, and grape.Designers and builders in the south learned the principles of shading windows long ago. Traditional architecture in hot climates often included wrap-around porches that kept direct sun out of the house, while providing pleasant outdoor living space. (Part of resilient design is looking at how our grandparents or great grandparents built — and returning to some of this vernacular architecture that is so well-adapted to the local climate.)Reflective roofs and wallsLight-colored roofs and walls reflect, rather than absorb, most of the sunlight striking them. By not heating up as much, less heat is transmitted through to the interior. With high insulation levels in roofs and walls (see below), the need for reflective exterior surfaces is less important, but this strategy can still make a difference.High insulation levels and tight constructionJust as an energy-efficient building envelope reduces heat loss in the winter, it also reduces unwanted heat gain during the summer — thus helping to control cooling loads and maintain comfort.If we follow the sort of recommendations for insulation levels for resilient homes that were outlined a couple weeks ago, unwanted heat gain will be very effectively controlled in the summer — as long as windows are closed during the hottest days.Natural ventilationFinally, we can achieve resilient homes that won’t get too hot if power is lost and air conditioning doesn’t work through natural ventilation. This strategy is particularly effective at night, when it’s cooler outside than in.Simple operable windows with screens offer the primary strategy here, but we can go further. In hot, sunny climates, such as the Southwest, one can build solar chimneys that use the natural buoyancy of warm, rising air to pull in cooler outside air — sometimes through inlet tubes buried in the ground (earth tubes). Operable windows high on a wall or skylights can also serve as solar chimneys.All of these natural cooling strategies can keep a house safe and reasonably comfortable in the summer during power outages. During normal times, such measures will significantly reduce the amount of time an air conditioner has to operate, while keeping the house more comfortable.last_img read more

No takers for Tunday’s kebabs without beef

first_imgFor more than a century, Tunday Kababi, Lucknow’s iconic kebab shop, has satisfied connoisseurs with its delicious galawati kebabs made from buffalo meat. On any given day, the restaurant in the heart of old Lucknow’s Chowk locality bustles with customers, who do not mind waiting in long queues for a bite of their favourite kebabs.But all that had changed on Thursday with only a couple of tables occupied and most waiters sitting idle. There was an unusual calm at the place, a far cry from its daily business.“Aap khud hi dekh sakte hai, kaisa sannata hai. Aaram se baithe hai hum, aam dino mein baithne ki fursat nahi hoti. (You can see for yourself how deserted the place is. Under normal conditions, we would not have a moment to rest),” says Tunday’s caretaker Mohammad Farooq.The iconic restaurant has been hit hard by a shortage of buffalo meat following the State government’s crackdown on illegal slaughterhouses. As buffalo meat is no longer available, Tunday Kababi’s Chowk outlet was forced to shut down on Wednesday. It reopened on Thursday but with the USP of its menu missing. For the first time since its inception, the restaurant served mutton and chicken kebabs, instead of its mainstay, beef. Stickers pasted on the walls of the outlet informed customers of the change.“This is for the first time in my 62 years of life that this joint is selling chicken kebabs. We have always sold beef. The customers come here especially for bade ka kabab (beef kebabs) and do not care much about other meat,” says Mr. Farooq.Customers unhappyAs their favourite items go missing from the menu, the flow of customers has also dipped. Mohammad Tauqeer, a retired government official, arrived at the outlet to purchase his favourite beef kebabs and paranthe but was disappointed. Would he try the chicken or mutton kebabs? “I am not interested [in mutton and chicken]. I just don’t get the same taste,” Mr. Tauqeer said, as he walked off empty-handed.Abbas (29), arrived to encounter the same dilemma. He, was, however, ready to give the new items a try. “I am a foodie. It is difficult to replace the taste [of beef kebabs]. It is not the same,” he said.In its election manifesto, the BJP promised to shut down all mechanised abattoirs and illegal slaughterhouses in U.P. Within a couple of days after coming to power, the Adityanath government swung into action, sealing slaughterhouses allegedly running without licence. “We welcome the move to shut illegal slaughterhouses. We request the government to ensure that those slaughterhouses with licence be allowed to run,” said Mr. Farooq.last_img read more

Five policemen suspended for violence in Puri

first_imgFive police personnel were placed under suspension for alleged dereliction of duty during vandalising of public property in Puri on October 3.Five police personnel, including four constables and one havildar, reportedly failed to control a group of people that attacked the house of Revenue and Disaster Management Minister Maheswar Mohanty, who is the local MLA.Violence had erupted in the coastal town during the bandh called by Jagannath Sena protesting against the ‘dhadi darshan’ (queue system for entering the temple) introduced by the Shree Jagannath Temple administration on the recommendation of the Supreme Court-appointed amicus curiae Gopal Subramanium.Protesters had also attacked the house of Puri Superintendent of Police Sarthak Sarangi.The police arrested 15 more protesters on Sunday taking the total number of arrests to 38. The district police had rounded up a total of 47 protesters who, as per CCTV footage, were reportedly found participating in violence The Supreme Court is monitoring reforms being undertaken in the 12th-century temple where devotees have long been alleging ill-treatment in the hand of servitors.last_img read more