Thursday, April 10, 2008

NATURAL RESOURCES

Home cooling

When the outside temperature soars your normally cool, comfortable home can become the last place you want to be. Thankfully, there are a range of options available to help you control indoor temperatures.The main ways that heat enters the home in summer are through:

Heat transfer from the external surfaces of the house that are warmed by the external air temperature and the sun

The sun shining through windows directly heating the home interior

Hot air infiltration through open windows, doors, air vents and gaps around doors and windows .

EVAPORATIVE COOLERS
Evaporative coolers range from small mobile units which cool one room up to large units that can cool a whole house. They consist of a fan or blower that draws in outside air and passes it through a wet filter. As hot dry air moves through the filter, water evaporates, cooling and humidifying the air. The cool air is then blown through the room or house.Evaporative systems cool best when the air is drawn slowly over the wet filter pad, which allows maximum evaporation to occur. Systems with larger total filter areas will provide better cooling because the air can flow more slowly over the filter pads. Care should be taken when purchasing evaporative systems to ensure that the unit is adequately sized for your particular requirements.

. Most roof-mounted systems are quite large and some can be noisy outside so you should consider the visual and noise aspects when choosing placement.Operating tipsWhen operating an evaporative cooler, always ensure that some doors or windows are slightly open so that the fresh, cool air produced by the air conditioner can easily flush out the hot air inside your home. Some ducted coolers have self-closing ceiling vents which allow the air to be exhausted into the roof space.

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Advantages of solar energy
Solar energy is a renewable resource that is environmentally friendly. Unlike fossil fuels, solar energy is available just about everywhere on earth. And this source of energy is free, immune to rising energy prices. Solar energy can be used in many ways - to provide heat, lighting, mechanical power and electricity.

Passive solar energy
Passive solar heating and cooling represents an important strategy for displacing traditional energy sources in buildings. Anyone who has sat by a sunny, south-facing window on a winter day has felt the effects of passive solar energy. Passive solar techniques make use of the steady supply of solar energy by means of building designs that carefully balance their energy requirements with the building's site and window orientation. The term "passive" indicates that no additional mechanical equipment is used, other than the normal building elements. All solar gains are brought in through windows and minimum use is made of pumps or fans to distribute heat or effect cooling.


Another solar concept is daylighting design, which optimises the use of natural daylight and contributes greatly to energy efficiency. The benefits of using passive solar techniques include simplicity, price and the design elegance of fulfilling one's needs with materials at hand.

Passive solar heating
Passive solar heating of buildings occurs when sunlight passes through a window, hits an object, is absorbed and converted to heat. The most efficient window orientation for heat gain is due south, but any orientation within 30 degrees of due south is acceptable. Once the heat has entered the building, various techniques come into play to keep and distribute it. Even in the Canadian climate, the prevention of overheating in the sun space presents one of the biggest challenges.


High efficiency windows, together with R-2000 levels of insulation and air-tight construction allow passive solar heating to cover a large proportion of heating needs in many locations. With the heat contained, often a simple ceiling fan or a forced air furnace fan (furnace burner off, of course) is all that is required for heat distribution. Using building envelope upgrades alone, up to 25 per cent of a building's heating requirement can be gained with passive solar techniques.



. Renewables are Not New
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It wasn't until the latter stages of the Industrial Revolution, the mid-1850s, and following the widespread incorporation of the steam-engine into factories, that fossil fuel use, mainly coal and oil, became commonplace. By incorporating fossil fuels into the manufacturing process instead of using water, industrialists were not limited to locations by rivers or streams. Plants could be located closer to sources of raw materials, markets or major shipping ports.

Wind Energy
The energy from the wind can be harnessed by wind turbines and windmills to generate electricity and also to pump water.
References

Advantages of solar energy
Solar energy is a renewable resource that is environmentally friendly. Unlike fossil fuels, solar energy is available just about everywhere on earth. And this source of energy is free, immune to rising energy prices. Solar energy can be used in many ways - to provide heat, lighting, mechanical power and electricity.

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