Saturday 25 June 2011

Low Powered Personal Air Conditioning

Conventional air conditioning requires an entire room or at least a cabin to be cooled by a 0.75 ton and above air conditioning unit. As the size of the room increases the power requirements of the AC increase too. Even if the number of people in the room are few or even one, the AC has to cool the entire room. For the common man, this luxury is in-affordable. The overall heat generation of these ACs in the environment and the subsequent increase in surrounding temperatures is another factor to be kept in mind.

Most people generally have a refrigerator in their homes, even if it is a small one like a 165 Litre model. It consumes about 400 to 500 Watts of power and its monthly bills are affordable. Now if we take a refrigerator like that and reshape it in the form of a custom bubble over an office chair, a relaxing sofa or a bed, then it becomes a personal AC that provides just the right cooling to the individual without the need to cool the entire room. The power bills will be very low just like having another refrigerator. Large rooms will not have to be cooled, instead just the individual seating or sleeping area is cooled. Receptionists, security personnel, sitting in large halls need not suffer in the heat. They can be provided with this system for of personal cooling. You come home tired due to the heat and daily grind and simply relax in your AC enabled sofa without worry. When you sleep in the night you don't worry about your power bills for the full night's room cooling. Just sleep cool in your personal AC bubble bed. For commercial organisations, it will have an added advantage of the employees not wanting to leave their personal AC chairs to kill time elsewhere. Heat generation of these devices will also be low just like a small refrigerator. Power to these devices is switched on only when the person is using it.

Materials used in these AC chairs, sofas and beds should be the type that are best suited for efficient and quick cooling. Some amount of outside air should also be mixed with the air inside to keep the air healthy.

Low Cost Room Cooling

All over the world, cities are becoming more and more congested with people living out of rectangular boxes that are called flats. There is no proper ventilation and the only cooling option available is installing an air conditioner. However air conditioners consume huge amounts of power making it in-affordable to the masses. A bigger problem with ACs is that they generate huge amounts of heat that is dissipated outside the buildings or rooms into the surrounding atmosphere causing an increase in the overall temperature in the vicinity. Ceiling fans provide air circulation but they circulate the same hot air over and over again. As hot air rises towards the ceiling, it is pushed down by the fan and the cycle gets repeated.

Now if the cycle of air circulation was reversed and the top half of the room was designed to cool the air, then hot air from the room gets pushed upwards, gets cooled and cold air falls to the ground, creating a cooling air current. To achieve this, the top half of the room's walls as well as the ceiling can be covered with a special material that is porous and lined with capillaries. Water is supplied into this material in a regulated manner to let it remain constantly moist. The ceiling fan's blades are designed to push the air up instead of down. The hot air from the room is now pushed upwards into the moist ceiling and wall panels and this causes a cooling effect due to evaporation. The cooler heavier air now moves downwards from the sides and provides an overall cooling comfort to the people in the room. For a better heat transfer, the cooling panels can be designed to have three dimensional extrusions to add more moist surface area and provide some resistance to trap the air as it flows over those surfaces. By covering the top half walls and ceiling with moist panels, we get a fairly large surface area for heat exchange. The water supply to the panels can be from the regular domestic pipes with special regulators to provide only a trickle flow that is just enough to keep the panels moist. Water from the wash basins and baths that generally flows down the drains, can also be filtered, cleaned and recycled to be used in these panels.

Similar moist panels placed on the outer walls of a building or bungalow and on the roof, can also help in reducing the overall temperature of the building. Automobiles fitted with these panels on the outside over the existing body will also run cooler than those with conventional metal surfaces that fully absorb the sun's heat.

Rolling Over Water At High Speeds

At present all water transport vessels glide over the surface of water. The surface of water offers friction and drag. The focus of designing water crafts is to reduce friction as much as possible and attain more speeds with stability. However instead of trying to reduce this friction, why not use it at high speeds. At speeds of over 100 mph, when a water skier releases himself from his rope, he does not sink in the water but keeps rolling over it till his speed drops low enough for him to stop. At high speeds the water's surface is so hard that objects can roll over it.

Suppose we have a craft that has 4 balloon type wheels appropriately shaped at it's side, just like a racing car. From zero to 80 mph, it uses conventional propulsion techniques as in speed boats. As it starts to gain more speed, its wheels are slowly lowered into the water and power is simultaneously transferred into them to rotate at exactly the same speed as the craft over the water. Once they are able to roll properly and in proportion with the friction of the water, power from the propellers is disengaged and full power is given to the wheels. The wheels are now riding over the hardened surface of water just like a car or a bus rides on a road. This technology will usher in a new era of high speed commuter water transport in the form of coastal water buses and water transport trucks.