Thursday, February 26, 2009

10 tips to save fuel cars

By Aaron Gold,

Whether you drive a two-seat hybrid or a three-ton SUV, chances are you can squeeze a bit more distance out of each gallon of fuel -- and at today's gas prices, an improvement of just one or two miles per gallon (MPG) can really add up. These ten fuel saving tips have served me well over the years, and they can help you improve your car's fuel economy and take some of the sting out of high fuel prices. Most of these tips will give you a very slight increase in MPG -- but use several together and the gas mileage improvements will really add up.

1. Slow down

One of the best ways to save gas is to simply reduce your speed. As speed increases, fuel economy decreases exponentially. If you one of the "ten-over on the freeway" set, try driving the speed limit for a few days. You'll save a lot of fuel and your journey won't take much longer. (Just be sure you keep to the right, so you won't impede the less-enlightened.)

2. Check your tire pressure

Under-inflated tires are one of the most commonly ignored causes of crummy MPG. Tires lose air due to time (about 1 psi per month) and temperature (1 psi for every 10 degree drop); under-inflated tires have more rolling resistance, which means you need to burn more gas to keep your car moving. Buy a reliable tire gauge and check your tires at least once a month. Be sure to check them when they are cold, since driving the car warms up the tires along with the air inside them, which increases pressure and gives a falsely high reading. Use the inflation pressures shown in the owner's manual or on the data plate in the driver's door jamb.

3. Check your air filter

A dirty air filter restricts the flow of air into the engine, which harms performance and economy. Air filters are easy to check and change; remove the filter and hold it up to the sun. If you can't see light coming through it, you need a new one. Consider a K&N or similar "permanent" filter which is cleaned rather than changed; they are much less restrictive than throw-away paper filters, plus they're better for the environment.

4. Accelerate with care

Jack-rabbit starts are an obvious fuel-waster -- but that doesn't mean you should crawl away from every light. If you drive an automatic, accelerate moderately so the transmission can shift up into the higher gears. Stick-shifters should shift early to keep the revs down, but don't lug the engine -- downshift if you need to accelerate. Keep an eye well down the road for potential slowdowns. If you accelerate to speed then have to brake right away, that's wasted fuel.

5. Hang with the trucks

Ever notice how, in bad traffic jams, cars seem to constantly speed up and slow down, while trucks tend to roll along at the same leisurely pace? A constant speed keeps shifting to a minimum -- important to those who have to wrangle with those ten-speed truck transmissions -- but it also aids economy, as it takes much more fuel to get a vehicle moving than it does to keep it moving. Rolling with the big rigs saves fuel (and aggravation).

6. Get back to nature

Consider shutting off the air conditioner, opening the windows and enjoying the breeze. It may be a tad warmer, but at lower speeds you'll save fuel. That said, at higher speeds the A/C may be more efficient than the wind resistance from open windows and sunroof. If I'm going someplace where arriving sweaty and smelly could be a problem, I bring an extra shirt and leave early so I'll have time for a quick change.

7. Back off the bling

New wheels and tires may look cool, and they can certainly improve handling. But if they are wider than the stock tires, chances are they'll create more rolling resistance and decrease fuel economy. If you upgrade your wheels and tires, keep the old ones. I have fancy sport rims and aggressive tires on my own car, but I keep the stock wheels with a good narrower-tread performance tire in the garage. For long road trips, the stock wheels give a smoother ride and better economy.

8. Clean out your car

If you're the type who takes a leisurely attitude towards car cleanliness -- and I definitely fall into that category -- periodically go through your car and see what can be tossed out or brought into the house. It doesn't take much to acquire an extra 40 or 50 lbs. of stuff, and the more weight your car has to lug around, the more fuel it burns.

9. Downsize

If you're shopping for a new car, it's time to re-evaluate how much car you really need. Smaller cars are inherently more fuel-efficient, and today's small cars are roomier than ever -- one of my favorite subcompacts, the Nissan Versa, has so much interior room that the EPA classifies it as a mid-size. Worried about crash protection? The automakers are designing their small cars to survive crashes with bigger vehicles, and safety features like side-curtain airbags and electronic stability control are becoming commonplace in smaller cars.

10. Don't drive

Not a popular thing to say on a car site, I know, but the fact is that if you can avoid driving, you'll save gas. Take the train, carpool, and consolidate your shopping trips. Walking or biking is good for your wallet and your health. And before you get in your car, always ask yourself: "Is this trip really necessary?"
source from:


Friday, February 20, 2009

Global Warming Effect

Ice Under Fire: Antarctica

Disintegrating face of the MÕller Ice Shelf

The disintegrating face of the Müller Ice Shelf, Lallemand Fjord, Antarctic Peninsula, 67° South, April 2, 1999. This small shelf, fed by glaciers from the Loubet Coast, has been receding recently after growing over a 400-year cooling period. Like other receding ice shelves such as the larger Larsen, it may be a sensitive monitor of rising regional temperatures. The Larsen Ice Shelf lost a 1200 square mile section early in 2002. Earlier in the 1990's other huge sections of this shelf disintegrated. In 2003 Argentine glaciologists reported that the land-based glaciers exposed by the removal of those sections had surged rapidly into the ocean. Thus, although ice shelves are floating and do not add to sea level when they melt or break up, land based glaciers released by such events definitely will add to sea level.

Muller Ice Shelf calving rapidly

Satelitte photo from NSIDC.orgAnother view of the Müller Ice Shelf calving rapidly (right). Across the Peninsula, seven monitored ice shelves have declined by a total of about 13,500 km2 since 1974, according to the National Snow and Ice Data Center. This is nearly the area of Connectcut. On the Larsen shelf (satellite view left), about 3,250 km2 of shelf in area B disintegrated in a 35-day period beginning on 31 January 2002. Eugene Domack, Hamilton College geologist, and others believe this portion of the shelf may have been stable for about 12,000 years before this year's collapse.

Technicians prepare a kasten core device.Technicians for the National Science Foundation on the rear deck of the research vessel, Nathaniel B. Palmer, prepare a kasten core device to lower into sediment near the Müller Ice Shelf. This is during a study by Dr. Eugene Domack, funded by the National Science Foundation, on the history of climate in peninsular Antarctica. All ice shelves in the area have been receding, but because they were already floating they do not raise sea level. The concern is that landed glaciers behind the shelves may be next to begin rapid retreat, which would raise ocean levels.

Marr Ice PiedmontThis mile-long ice cliff of Marr Ice Piedmont, Anvers Island, has receded about 500 meters since the mid 1960s. The cliff's previous position was to the left of the line of ice floating in the harbor and extended to the headland at the extreme upper left. The regional temperature has increased 5° C in winter over the past 50 years. This reduces seasonal icepack, disrupts growth of krill and changes conditions on penguin rookeries.

For more on glacier recession and around the world, please see Ice Under Fire, the Mountain Glacier section.

Pushing the Boundaries of Life: Antarctica

A colony of Adelies on Humble Island

A colony of Adelies on Humble Island, one of eight islets off Anvers Island where thousands of Adelies have nested for some 600 years. Over the last 25 years these Adelie colonies have declined sharply. Chinstrap penguins are moving rapidly into Adelie territory. Archaeological digs in penguin colonies indicate there probably were no chinstraps in this area until about 50 years ago, when average temperatures began to rise.

Bill Fraser at former Adelie colongy on Torgersen Island

Ornithologist Bill Fraser stands on the smooth pebbly surface of a former large colony of Adelie penguins on Torgersen Island. Unlike the colony in the photo above, this nesting site has been used by fewer and fewer penguins over recent years. Analyzing climate data, island topography, and breeding statistics, Fraser believes climate change caused the loss of half of its 16,000 nesting Adelies. Warming temperatures and more open water make for greater snowfall and more difficult hunting for krill, affecting nesting success. These changes are seen in other Adelie colonies on the Antarctic peninsula, but elsewhere in Antarctica, climate change either is favorable to the birds or is not affecting them.

A male Adelie disgorges krill for its chickA male Adelie penguin, back from a long feeding trip, disgorges krill for its chick. Krill develop best under seasonal ice, so thinner, less extensive winter ice can reduce the size of the shrimp-like Antarctic staple. The tiny radio transmitter on this bird's back allows Dr. Fraser to monitor how far and for how long penguins hunt for food. For some colonies, hunting times are becoming longer and longer as diminished seasonal sea ice extends the distance from rookery to feeding ground.

Although the Adelie penguin is not threatened as a species by global warming or man-caused problem so far, many species of this bird are. In a landmark decision that nevertheless fell short of conservationists' proposals, the US Fish and Wildlife Service proposed seven penguin species as candidates for 'threatened" status under the Endangered Species Act.

Included in the December 2008 document are the African penguin, yellow-eyed penguin, white-flippered penguin, Fiordland crested penguin, Humboldt penguin, and erect-crested penguin and a portion of the range of the southern rockhopper penguin. However, the ruling denied listing for the majority of the range of the southern rockhopper penguin, as well as for the northern rockhopper penguin, macaroni penguin, and emperor penguin.

The emperors, the ones in the film "March of the Penguin" are among species which are losing numbers apparently due to warming seas, reduced summer sea ice, and lack of their prime food, krill. If the candidate species are found by additional study and public comment to be worthy of being listed, they will receive protection under the Endangered Species Act sometime in 2009.


Thursday, February 19, 2009

Global Warming

Global Warming

Upsetting a delicate balance In the past the Earth's climate has changed as a result of natural causes in our atmosphere.

The changes we are witnessing and those that are predicted are largely due to human behaviour: we are burning fossil fuels, and heating up the planet at the same time. We blow exponential amounts of carbon dioxide (CO2) into the atmosphere every year – 29 billion tonnes of it (2004) and rising – and this warms the globe.

Since the Industrial Revolution, humans have been burning fossil fuels on a massive scale. We use this energy, almost without care for the consequences, to run vehicles, heat homes, conduct business, and power factories.

Burning fossil fuels releases carbon dioxide stored millions of years ago as oil, coal or natural gas. In the last 200 years we have burned a large part of these stores, resulting in an increase in CO2 in our atmosphere. Deforestation also releases CO2 stored in trees and in the soil.

The increase of CO2 in the atmosphere thickens the 'greenhouse blanket', with the result that too much heat is trapped into the Earth's atmosphere. This causes global warming: global temperatures rise and cause climate change.

Note: CO2 is the most important gas causing global warming. Others include methane (CH4), nitrous dioxide (NO2), and several artificial gases (Hydrofluorocarbons (HFCs), Perfluorocarbons (PFCs); and Sulphur hexafluoride (SF6). These 6 groups are accounted for under the Kyoto Protocol.

Sea Ice Extent Comparison at the North Pole - mimumum ice reach comparison between 1979 and 2005. © NASA

Current statistics

Data from the World Resources Institute show that humans have added 2.3 trillion tonnes of CO2 to the atmosphere in the last 200 years. Half of this amount was added in the last 30 years. The largest absolute increase in CO2 emissions occurred in 2004, when burning fossil fuels alone added more than 28 billion tonnes to the atmosphere.
Source: WRI, Navigating the numbers, based on data from IEA, EIA, Marland et al, and BP.

Overall, the concentration of CO2 in the atmosphere has increased by 31% since 1750, i.e. since the Industrial Revolution. CO2 emissions are now around 12 times higher than in 1900 as the world burns more and more coal, oil and gas for energy. A 1999 study by Mann et al. shows the dramatic increase in temperature in the Northern Hemisphere in the last 50 years. This well-known hockey stick curve has been validated by numerous other scientists.

The (not too distant) future

We simply cannot continue pumping CO2 into the atmosphere without curbs and controls. Even with the best case scenario for the increase in CO2 emissions it is predicted that the concentration of CO2 in the atmosphere will reach double the level of before the Industrial Revolution by 2100. The worst case scenario brings this doubling forward to 2045 – less than 40 years from now! The Third Assessment Report of the UN's Intergovernmental Panel on Climate Change (IPCC) predicts global temperature rises by the end of the century of between 1.4°C and 5.8°C.

The Earth’s climate is driven by a continuous flow of energy from the sun. Heat energy from the sun passes through the Earth’s atmosphere and warms the Earth’s surface.

The fragile atmosphere protects us from the universe.
As the temperature increases, the Earth sends heat energy (infrared radiation) back into the atmosphere. Some of this heat is absorbed by gases in the atmosphere, such as carbon dioxide (CO2) , water vapour, methane, nitrous oxide, ozone and helacarbons.

The greenhouse effect

These gases, which are all naturally occurring, act as a blanket, trapping in the heat and preventing it from being reflected too far from the Earth. They keep the Earth's average temperature at about 15°C: warm enough to sustain life for humans, plants and animals. Without these gases, the average temperature would be about minus 18°C - too cold for higher life. This natural warming effect is also sometimes called the greenhouse effect.

Carbon dioxide (CO2)

CO2 is the most significant of the gases in our atmosphere which keep the Earth warm. Four billion years ago its concentration in the atmosphere was much higher than today (80% compared to today's 0.03%), but most of it was removed through photosynthesis over time. All this carbon dioxide became locked in organisms and then minerals such as oil, coal and petroleum inside the Earth's crust.

The natural carbon dioxide cycle

A natural carbon dioxide cycle keeps the amount of CO2 in our atmosphere in balance. Decaying plants, volcanic eruptions and the respiration of animals release natural CO2 into the atmosphere, where it stays for about 100 years. It is removed again from the atmosphere by photosynthesis in plants and by dissolution in water (for instance in the oceans).

The amount of naturally produced CO2 is almost perfectly balanced by the amount naturally removed. Even small changes caused by human activities can upset this equilibrium.

The world is warming faster than at any time in the last 12,000 years. The 1990s was the hottest decade in the past millennium.

As global warming tightens its grip, the effects are being felt from the highest mountain peaks to the depths of the oceans. In just the last few years there are numerous examples of how this is affecting people and nature all over the world.
  • Global warming is melting glaciers in every region of the world, putting millions of people at risk from floods, droughts and lack of drinking water.

  • March 2006 showed the smallest Arctic sea ice cover ever measured. In the space of one year an area about the size of Italy was lost. The National Snow and Ice Data Center in the United States found that sea ice extent had reduced by 300,000 square km in comparison to March 2005, itself already a record low year.

  • 2003, Scotland's hottest year on record, saw hundreds of adult salmon die in Scotland’s famous fisheries, as rivers became too warm for salmon to be able to extract enough oxygen from the water.

  • Coral reefs around the world have been severely damaged by unusually warm ocean temperatures. The Caribbean saw its warmest ever ocean temperatures in 2005, combined with the worst coral bleaching ever. At the current rate of degradation, the entire Great Barrier Reef could be dead within a human lifetime.

  • Cities like Athens, Chicago, Milan, New Delhi and Paris have sweltered under heatwaves. The 2003 summer heatwave in Europe killed 14,800 people in France alone, according to official figures released in September 2003. The French National Institute for Health and Medical Research said that the death rate was on average 60% higher than usual.

  • Summer temperatures in European capitals have increased by up to 2°C over the last 30 years, a WWF report showed.

  • Rising sea levels threaten entire nations on low-lying islands in the Pacific and Indian Oceans. Read how WWF South Pacific tries to help concerned villagers.

  • A report released by WWF and leading meteorologists shows that human-induced global warming was a key factor in the severity of the 2002 drought in Australia, generally regarded as the worst ever.


Wednesday, February 18, 2009

What is Climate Change ?

Earth’s climate is changing. Greenhouse gases are accumulating. Human activities are the cause.

Further Resources

The Intergovernmental Panel on Climate Change (IPCC)


The build-up of greenhouse gases (GHGs) threatens to set the Earth inexorably on the path to a unpredictably different climate. The Intergovernmental Panel on Climate Change (IPCC) says many parts of the planet will be warmer. Droughts, floods and other forms of extreme weather will become more frequent, threatening food supplies. Plants and animals which cannot adjust will die out. Sea levels are rising and will continue to do so, forcing hundreds of thousands of people in coastal zones to migrate.

One of the main GHGs which humans are adding to the atmosphere, carbon dioxide (CO2), is increasing rapidly. Around 1750, about the start of the Industrial Revolution in Europe, there were 280 parts per million (ppm) of CO2 in the atmosphere. Today the overall amount of GHGs has topped 390 ppm CO2e (parts per million of carbon dioxide equivalent – all GHGs expressed as a common metric in relation to their warming potential) and the figure is rising by 1.5–2 ppm annually. Reputable scientists believe the Earth’s average temperature should not rise by more than 2°C over pre-industrial levels. Among others, the European Union indicated that this is essential to minimize the risk of what the UN Framework Convention on Climate Change (UNFCCC) calls dangerous climate change and keep the costs of adapting to a warmer world bearable. Scientists say there is a 50 per cent chance of keeping to 2°C if the total GHG concentration remains below 450 ppm.


Climate change is here to stay. But it is still in our power – as individuals, businesses, cities and governments – to influence just how serious the problem will become.

Further Resources

Climate Neutral Network Website

» Twelve Steps to Help You Kick the CO2 Habit
» Climate Change Adaptation and Mitigation in the Tourism Sector

Whether you are an individual, an organization, a business or a government, there are a number of steps you can take to reduce your carbon emissions, the total of which is described as your carbon footprint. You may think you don’t know where to begin, but by reading this, you have already begun.

Indeed, some quite simple ‘no regrets’ measures can more than halve the daily emissions of an individual, with even bigger cuts possible if sectors like power suppliers and automobile makers as well as aviation and appliance manufacturers contributed more to the greening of global lifestyles.

Individuals who reduce their energy consumption and thus their climate impact also save money. On a more macro-economic level, economic opportunities arise from measures taken to reduce GHGs: insulating buildings for example will not only save energy costs, but also give the building sector an enormous boost and create employment. While some sectors might suffer increased costs, many will seize the opportunity to innovate and get a step ahead of their competitors in adapting to changed market conditions.

Many companies, cities, organizations and indeed whole countries are embarking on strategies to achieve even zero emission businesses, communities and economies. A great deal of this transition to a green economy is being federated and empowered under the banner of UNEP's Climate Neutral Network (CN Net) which was launched in February 2008.

Some low-carbon lifestyle choices at home, in the office and when traveling include:

  • Waking up with a traditional wind-up alarm clock rather than the beep of an electronic one - this can save someone almost 48 grams (g) of CO2 each day;
  • Choosing to dry clothes on a washing line versus a tumble dryer - a daily carbon diet of 2.3 Kg of CO2;
  • Replacing a 45-minute workout on a treadmill with a jog in a nearby park. This saves nearly 1 Kg of the main greenhouse gas;
  • Opting for non-electric toothbrush will avoid nearly 48g of CO2 emissions;
  • Heating bread rolls in a toaster versus an oven for 15 minutes saves nearly 170g of CO2;
  • Switching from regular 60-Watt light bulbs to energy-saving ones will produce four times less greenhouse gas emissions;
  • Taking the train rather than the car for a daily office commute of as little as 8 km will save a big 1.7 Kg of CO2;
  • Shutting down your computer and flat screen both during lunch break and after working hours will cut CO2 emissions generated by these appliances by one-third;
  • Investing in a water-saving shower head will not only save 10 liters of water per minute, but will also slash CO2 emissions resulting from a three-minute hot shower by half;
  • Reducing the weight of goods and items carried onboard by airline passengers to below 20Kg could cut global GHG emissions by two million tonnes of CO2 a year.


Wednesday, February 11, 2009

AC Control

Tips & Tricks

The ultimate objective of any serious energy conservation program for a sizeable facility is a central, computer automated electronic controls system. This integrated system of remote sensors and control devices permits the optimum use of energy in all areas while simultaneously providing the best environment for building occupants.

  • Optimized start/stop of air handling units
    This is a more sophisticated use of the on/off controls of all the air handling units in a building. Instead of a complete cut off of power to a unit the thermostat setting is setback at night and on weekends. The advantage over full on/off controls is that when units are turned off all night they must work extra hard to return the space to the comfort zone in the morning. This is especially important during the heating season, when the peak load often occurs shortly after the office opens in the morning.

    Operation of the equipment to maintain a nominal space temperature all night reduces the energy needed to start up, so the equipment can be sized to satisfy a smaller peak load. This, in turn, translates into less expensive air handlers and ones that operate nearer their most efficient, full load condition.

    Another common use of the central control of air handlers is to turn the equipment off, or initiate the night setback sequence, an hour or two before the end of the day. The thermal momentum of the building mass and the volume of air already conditioned will maintain space temperatures within the comfort zone for the balance of the day. This affect is especially useful when the supply and return air fans continue to circulate air after the heating or cooling system is disabled, thereby extracting any residual heat from the circulating fluids or the building mass. The continued movement of air, even as the temperature floats away from the setpoint, will make the space more comfortable to the occupants.

  • Demand limiting
    The demand limiting philosophy is to begin turning off pieces of equipment as the electrical use approaches the peak. The software, already programmed with a prioritized list of items to be turned off, simply follows the list until the energy use curve is leveled off and the peak load passes. Clever programmers will make use of the building mass to provide some thermal momentum during these periods, extracting or rejecting heat to the building while the HVAC is turned off to always maintain a comfortable environment.

  • Peak load shifting
    Some systems accomplish demand limiting by shifting the building load to off peak hours. One way to do this is to run the chillers during the night to chill water that is stored in large tanks on the premises. Then during the peak building load the following day the chillers are turned off and the ready-made chilled water is circulated to the building loop. Other systems make ice in the night and melt it later to chill the loop water.

    This same sort of technique can be used on a smaller scale, using simple controls. There are several thermal masses that can be used to store energy during off-peak hours: the building mass, the volume of fluid in the chilled water loop, the volume of cooled air within the building and the humidity of the cooled air in the building. An hour or two before the peak load is expected (based on an average of previous days, or other criteria) the building and its systems are allowed to float below the set point, storing energy that is released for the next few hours until the peak is passed.

    The immediate demand on the system is met by the existing air volume, then by the chilled water resident in the closed loop. The air humidity then drifts upward as the warmer air is able to absorb thermal energy from the building environment. Finally, the building mass contributes to the system.

    Keep in mind that the peak load that the system is designed to handle typically lasts only a couple of hours. Use of the aforementioned dynamic elements, eg letting the temperature and humidity drift upward in the process, will greatly reduce the daily peak load. Also, since this load is usually at the end of the work day the entire system will be shut down soon and no additional energy will have to be input to make up for the excesses permitted, since the building will equalize with its environment through the night, possibly aided by artificial circulation of outside air.

  • Load leveling
    A plot of a typical day will indicate several peaks and spikes. A peak will show a gradual increase to maximum of, for example, the HVAC system as the building approaches the maximum load. Spikes may indicate the operation of the laundry or kitchen for an hour of intense activity, when copious quantities of hot water are used and generated rapidly, and electric equipment operates at high loading conditions.

    The use of energy to complete the necessary daily functions at the facility cannot be avoided. However, the timing is often flexible. Instead of operating the laundry in the middle of the afternoon, for example, when the HVAC is approaching its peak, the laundry can be done earlier in the day. This will not affect the actual energy used, but it will reduce the peak load because the baseline is lower. The lower daily peak, in turn, will reduce the demand fee charged by the utility.

    The ability to apply this principle of load leveling depends on a thorough understanding of the energy using equipment at a facility, plus knowledge of the daily routines that happen in every department. The best way for the engineering staff to attain this level of competence is to first document information on each major item of equipment, then follow an explicit maintenance program. Once a strong technical understanding is accomplished, then the facility management can be approached with the load leveling concept. If sufficient support is presented no doubt the decision will be made to reschedule certain activities to reduce the peak usage by shifting a part of the load to off peak hours.

  • Two stage controls
    There are numerous applications for two levels of controls. One example is a large room served by two air handlers. Instead of having both controlled by a single thermostat (which will resort to short cycling and excess energy use) or controlled by separate thermostats, a single controller will activate one unit, then both, as the space load demands. Many manufacturers have programmable thermostats with this function built in, for control of two stage compressors.

    Another common application for this simple device is to control a two speed motor of an air handler. The controlling function can be static pressure in the discharge duct to a variable air volume system. This is an inexpensive option to inlet vanes or a variable speed drive, and is a good compromise for system retrofits when the VFD is too costly. If the new two speed motor is a high efficiency model, there may be nearly as much savings as from installation of a VFD anyway, depending on the number of exterior and interior zones served by the air handler.

    If an air handler serves only a few zones, then the two speed motor can be interlocked with a space temperature sensor; that is, if the air distribution is not overly affected at the new air flow rate for a constant volume system. An ideal application of this method is a system serving, for example, two operating rooms in a hospital or two classrooms in an academic building. If only one of the spaces is in use the air ducted to the other can be dampered off, the motor put on low speed and the system operates at half capacity to adequately condition the one room.
© Copyright 2000.


Save Water

Save water

Did you know that water companies have to use energy to supply mains water to our homes? We then use more energy heating it up for baths, showers and washing up. Using energy means that carbon dioxide emissions will be generated, which contributes to climate change. The Energy Saving Trust is concerned about water waste and as an energy saver we think you should be too.

Each person in the UK currently uses about 150 litres of water every day, which has been rising by 1% a year since 1930 and much of this is wasted, disappearing down the plughole as we brush our teeth or being flushed down the toilet. For example, a dripping tap can waste as much as 5,500 litres of water a year, which is enough to fill a paddling pool every week for the whole summer. This consumption level is not sustainable in the long-term. If we do not take action now, climate change, population growth and increasing water demand mean the UK could face increased water stress in the future.

If we all made some simple and quick changes in our homes, we could save loads of water. Waterwise, the leading authority on water efficiency in the UK, has a list of top tips to help you start saving today.

Find out about water saving tips inside the home

Find out about water saving tips outside the home


Wednesday, February 4, 2009

The Water System

Tips & Tricks

The Water System
The water distribution system in a building is usually ignored as a potential energy conservation resource. It is a deceptively simple system, though, with many practical ways to optimize. These techniques can be divided into two general categories: reducing the use of water and reducing the heat lost from hot water piping.

  • Inspect for leaks
    A simple way to reduce water usage is to be alert for leaks in pipes, fittings, pumps and gauges in mechanical rooms and at headers throughout the building. Faucets and other restroom fittings are also important locations to inspect for fluid loss. Swift repair of these water leaks will prevent collateral damage to wood surfaces and furnishings, ceiling tiles and electrical equipment. The savings will occur in the water bill and in a lower sewage disposal fee as well.

    Leaks that occur in closed systems can be even more expensive. Water circulating in the chilled water loop, the condenser water loop and the steam loop is usually chemically treated for corrosion and high hardness. Water lost from these systems loses valuable chemicals as well, which increases the treatment costs. In addition, the energy needed to heat or cool the circulating fluid will rise since a portion of the energy spent is lost with the leakage of hot or cold water.

  • Reduce hot water storage temperature
    Whenever the water temperature at the point of use is too hot, copious quantities of cold water are needed to cool it to a satisfactory temperature. A slight reduction in hot water temperature will ensure it is delivered at the best temperature. Lowering the tank thermostat setting will also reduce the cost of keeping the water heated. A variation on this theme, called hot water reset, is practiced by large institutional users. A remote outside thermometer automatically increases the hot water supply temperature when the weather is warm. This can also be done by manually changing the setting at the beginning of the cooling season, then increasing it when the heating season begins.

  • More efficient operation of cleaning equipment
    A good portion of the hot water used at an institutional building is devoted to washing dishes in the kitchen and washing clothes in the laundry. If the equipment used for these tasks does not have settings for different size loads then it is most efficient to operate them only when full. Use of an economizer cycle, if available, is another energy saver; for example, drip drying dishes naturally instead of with forced heat. Adjusting the settings to wash and rinse with the coldest practical water temperature will also save energy without sacrificing quality.

  • Reduce volume of waste disposal methods
    Many commodes are now made with a smaller toilet flush tank to reduce the volume of water used with each cycle. The same principles have been applied in other appliances, for considerable savings. Such large users of water as clothes washers and dish washers benefit from water conserving practices, especially if the quantity of cleansers used are reduced so that less water is used in the rinse cycle.

  • Inspect and repair damaged insulation systems
    Sagging or missing sections of insulation should be promptly attended, as they are not only an energy loser but may also indicate a leaking pipe in need of repair. If the insulation is worn because it covers a pipeline in a heavy use area the insulation should be replaced, then covered with a sheet metal sleeve to prevent future damage.

  • Install time clocks on water heaters
    Most business offices are open during the daylight hours, Monday through Friday. Allowing for cleaning crews after hours, the time during which hot water is needed is perhaps sixty hours a week. The typical hot water heater is on all the time, 168 hours each week. A timer will greatly reduce this wasted energy. It can be set to turn on an hour of so before the beginning of the business day and still provide the same consistent service as though it were on constantly. Also, with extra down time, the heater will have a much longer useful life.

  • Insulate hot water heater(s) and storage tank(s)
    Many utilities will provide water heater "blankets" at no cost. Others offer rebates to businesses and individuals who purchase high efficiency hot water heaters that have adequate insulation built into the unit. If the heater is located within the conditioned space, heat emanating from the unit will add to the load on the air conditioning equipment. If it is located outside - and is poorly insulated - much heat will be lost in the winter to the environs. In either case it is important to maximize insulation.

  • Install flow restrictors at hot water faucets and shower heads
    This is another effective way to reduce water usage, while sacrificing little to convenience or necessity. To compliment such measures it is helpful to promulgate a general philosophy of water conservation, especially in the kitchen. People tend to think of water as an inexhaustible resource, not realizing the energy is saved by not wasting hot water.

  • Consider increasing pipe insulation thickness
    Many older buildings were built at a time when energy was inexpensive. The hot water piping may not have been insulated at all, or it could be wrapped with a minimal thickness. A high quality product is available that is more efficient and durable. Pipe routed through unconditioned spaces such as the pipe basement or attic should not be without insulation.

  • Consider instantaneous heaters at remote locations
    Several manufacturers offer small point of use instantaneous water heaters. If there are only a few locations in a building that require hotter water than the rest of the facility, these devices can help save energy - if the volume is low - by allowing the main hot water temperature to be reduced. This will reduce the thermal losses from the storage tank as well as from the loop piping.

  • Install a separate water heater for the kitchen or laundry
    A sophisticated hot water system, in a hospital for example, will be designed to supply 180 degree F water to the kitchen and laundry and 120 degree F water everywhere else. Many buildings will simply supply the hotter water everywhere, at great waste - and sometimes great danger, from the scalding hot water.
© Copyright 2000.


Sunday, February 1, 2009

Saving Energy in the Lighting

Tips & Tricks

Saving Energy in the Lighting
A fourth of all electricity sold in the United States is used for lighting. Most of this lighting is used in stores, offices, warehouses and factories. It is strange, then, that conserving energy with lighting projects is not a high priority for most businesses. They assume lighting is a fixed overhead item that cannot be substantially reduced as an expense.

One mistake businesses make is to concentrate on first cost and purchase the cheapest lamps. They do not bother to consider the life cycle cost of these lamps. This can be a big mistake, given the 20,000 hour life of a typical fluorescent lamp. Installation of more efficient lamps can pay for their modest extra cost many times over. Industries that ignore this reduce their own competitiveness by operating under an escalating overhead, increasing with the electric rate.

Any modifications to the original lighting design at a facility should be done so that the quality of the lighting environment is not diminished. Exact illumination levels have been established to be maintained for specific tasks in the workplace. A number of inexpensive projects can be done, however, that do not significantly affect the light levels. They can be implemented by the maintenance staff, often without engineering design or approval required.

  • Use fluorescent lamps for interior lighting
    Fluorescent lamps are much more efficient than incandescent lamps and should be used where possible, including task lighting and down lights. Compact fluorescent lamps are available that can be screwed directly into incandescent sockets. Thus they provide inexpensive lighting without sacrificing the convenience of incandescent lamps.

    High intensity discharge (HID) lamps are more efficient than incandescent flood lights and should be used in their stead. HID lamps are best suited for large interior spaces with a high ceiling such as lobbies and atriums. They are also ideal for locations that are hard to access, such as mechanical rooms or auditorium with high ceilings. HID lamps have a longer lifetime than either fluorescent or incandescent bulbs and do not have to be changed as often. Incandescent light sources are still best for some applications, such as pipe basements, housekeeping closets and other areas with special requirements such as darkrooms, photo labs and studios. Limited use of incandescent lamps in conference rooms and dining areas that need lamps to be dimmed is common, although fluorescent dimming systems are becoming more competitive and commonplace.

  • Arrange fixtures to suit furniture arrangements
    A general guideline for locating fixtures in a room that does not have fixed task locations is to position fixtures within 2 or 3 feet of walls. Then arrange fixtures in a regular pattern to provide a minimum light level, using task lighting at individual work stations.

    If the work spaces are well defined or the location of furniture known a general lighting layout is not necessary. Instead, lights can be positioned directly above the work surface and located in non-task areas to provide a lower ambient light level. The latter include aisle space and such traffic locations as doorways. Lights should not be placed in the arc of a door swing as area lighting in the rest of the room will generally provide adequate illumination there.

    These modifications to traditional lighting schemes are possible because the IES stipulates an ambient or average light level at the work surface. The zonal cavity calculation method generates this value in a space and when lighting designers specify fixtures according to these figures, the results can be deceptive. As an example, consider a common lighting design situation.

    Two three lamp fixtures in a small office may produce a calculated light level of 60 footcandles, while the light measured directly beneath either fixture may be 120 or more at the desk top level. One of the fixtures can be eliminated entirely. There will still be good light at the work surface and adequate light in the rest of the space, where only 20 or 30 footcandles are needed. The only contingency to this scheme is to insure that the contrast is not excessive between the work surface and its environs. In small office with light colored walls this should not be a problem.

    As another example consider a laboratory or shop with built in work tables and work benches. Adequate light can be provided by a row of fluorescent fixtures. They should be centered over the front edge of wall mounted tables and perpendicular to double sided tables in the middle of the room. Since fluorescent fixtures emit more light parallel to the axis of the lamps than crosswise so a solid row of lamps may not be necessary. Lights over open floor areas can be omitted altogether or reduced to provide a minimum level of light for contrast.

    A final case is a large storage room. If the shelve locations are fixed then fixtures located lengthwise over the aisles will make the most efficient use of lighting. If the shelve locations are not well known then a good alternative is to run fixture rows at 45 degrees to the room dimensions.

    In all of these cases a degree of flexibility can be built into the design, especially if a large floor space is to be illuminated. Each fixture can be wired with a few extra feet of flexible cable to permit shifting it in a variety of positions in the ceiling grid. They can even be wired with a quick disconnect cable so that fixtures can be moved from one space to another as the floor plan changes or lighting needs vary. This will cost a little extra up front. However, if the space usage is expected to change frequently this flexibility can save the cost of a complete rewiring job with each remodeling.

  • Limit decorative lighting
    Lighting in special areas such as conference rooms, lobbies, auditoriums and waiting rooms should be kept simple and functional. Special treatment for architectural purposes should use efficient fluorescent or HID lamps and should, where possible, double as general illumination. Decorative lighting of the building exterior should only be done if it is incidental to a functional lighting system.

  • Control exterior and parking area lighting
    Exterior lighting of walkways and building entrances can remain on during daylight hours or at other unnecessary times. If these lights are on a dedicated circuit they can be turned on and off independently by an electromechanical timeclock. Work hours do not always coincide with the hours of darkness. Often the exterior lights will burn when in is light out either before or after business hours. The time clock will automate this function and save the staff the trouble. It will have to be reset periodically, though, as the seasons pass. A photocell connected in series with the time will resolve this problem and further reduce the time the lights are in use.

    Lighting for parking lots and parking garages will benefit from these controls as well, to insure the lights operate only when needed. Further savings are possible from circuiting the luminaires in logical groups that can be cycled on and off during the night. For example, a multi-level parking garage can leave only one level on during the off hours. This will work especially well for buildings with an integral garage. Such facilities often have only a single access door after close of business, so most parking will be near this entrance anyway. Parking lots can follow the same method, security needs notwithstanding.

  • Use separate work station switching
    Large work spaces with individual work stations separated by partitions are common in laboratories and business offices. When a single person works late the entire space must be lit. An energy efficient alternative is to switch the lights so that one level will provide area lighting, then other switches at each logical work area will activate overhead lighting specific to that area.

  • Maximizing Use of Daylighting
    Any room with outside windows has daylighting available to supplement the artificial luminaires. There are three types of daylight that can enter a conditioned space: direct, indirect and reflected. Direct light is the least desirable because it can cause problems from glare and it also has the highest contribution to the cooling load for a space. Reflected light can have similar consequences unless it is carefully controlled.

    Some architectural features can be enhanced to increase the natural lighting available to a space. Reflective sills and properly angled venetian blinds can be used to amplify the flow of light through windows or opaque openings such as glass brick walls. Even directing the light straight up to a light colored ceiling will help, as the reflected light from this ceiling will reach deep into the room.

    Landscape features are also helpful to direct more natural light through windows. A reflective area on the ground beneath a ground level window - of gravel, a light colored wood or concrete - will direct more diffuse light through nearby wall openings. Carefully trimming shrubs, trees and ground covering around windows will also help. These plantings may be desirable around windows facing south or west in the summer, however, to prevent direct light from heating up the building excessively in the late afternoon. Many people will trim the plants anyway and use blinds or shutters when direct lighting is a detriment.

    The incentive for increasing natural lighting is that it is the best for color discrimination and detailed work such as drawing, painting or drafting. artificial lighting can be designed to approach the natural ideal, but no further. Consequently any method that can increase the natural light in a space will enhance the lighting environment, thereby improving the productivity and attitude of the people within.

    Another factor of daylighting to consider is that windows with closed blinds or curtains have a higher insulation value. This is offset by the fact that the lights in a room also generate a portion of heat that must be removed by the air conditioning. This may be as much as ten percent of the total load. With the exception of direct lighting, though, it is generally an energy saver to take advantage of the daylight and pay the small penalty in higher air conditioning cost.

    The electricity savings made possible by increased use of daylighting can take several forms. In a space that can turn off all lights when outside conditions are favorable, the total lighting cost can be considered the net savings. Even though the available natural light varies through the day and from season to season, the annual electricity savings could be as much as 60% of the lighting bill.

    A final alternative is to put the lights in a daylit space on a multi-level switching system. If the space has three-lamp fluorescent fixtures, for example, the ballasts can be modified to permit one, two or three lamp operation of the lights for three separate ambient light levels. This provides the flexibility of supplementing the daylighting the minimum necessary to provide the proper total footcandle levels.

    Each of these systems will permit immediate savings, depending on the type of controls used and the extent to which the present switching must be modified. The cost and payback calculations can be complex, and will be detailed in the forthcoming section on controls.

  • Reducing Illumination Levels
    Use of task lighting can reduce the footcandle levels in a space and reduce the electrical energy demand by 20% - 50%. Good areas to consider for this M & O are large open office areas where each workstation has a desk lamp, such as an engineering office that provides each drafting table with a lamp. In such instances the overhead lighting is no longer used to provide a task-specific illuminance, but serves only to supplement local light sources at each desk.

    Light levels can also be safely reduced in non-critical areas such as hallways, lobbies, waiting rooms, storerooms, mechanical rooms and restrooms. There are a number of ways to reduce the illumination levels. The best method to use depends on the type of lamps to be modified, incandescent or fluorescent. The energy saved will be in direct proportion to the reduction in wattage.

  • Project Strategy
    It is important before beginning a major lighting retrofit project to first become familiar with the lighting environment of your business. Doing one or two of the M & O's is a good way to understand lighting and to become familiar with the equipment and technology.

    A strong incentive, other than simple energy savings, concerns the effect of lighting on performance, accuracy, visual comfort and sometimes even morale and attitude. If your project is planned carefully and implemented properly not only will there result a savings in energy usage, but the working environment will be improved.

© Copyright 2000.



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