Solar ventilation systems, for both cooling and heating applications, are used mainly for Indian rural market.
Solar cooling or heating for poultry farm in rural India
The temperature in Indian rural areas varies from 6 to 520C throughout the year depending on the seasons. Maintaining 25 to 300C temperature during night-time in winter-season, when the ambient temperature is to the tune of 60C _ and maintaining the same temperature range during daytime in summer-season, when the ambient temp. is ~ 48 to 500C _ is a challenging but essential task.
In addition to this, availability of continuous and steady conventional electric-supply is an impossible and distant dream. Fortunately, we are rich in natural solar energy incident on our rural places. If it is properly collected and utilised with the help of the latest available technology, it can definitely improve the scenario prevailing in rural India.
Technology involved: A high-efficiency solarpanel mounted on poultry roof-top converts solar energy into electrical energy. The electrical energy thus generated drives the solar equipments in poultry including the cooling or heating fans during daytime directly online – and the balance energy is stored in the battery-bank, which is used for lighting, cooling and heating applications.
The technology is foolproof as the solar-panels used have a proven-life of 25 years and more. The solar-powered farm or poultry equipments are BLDC-based, hence they have a very long-life span of minimum 15 years. The Solar Torr Tubular batteries used have an average life span of 10 years or more. Hence, the overall system efficiency becomes good with excellent reliability. This is the future for healthy rural economy. This shall definitely help in cutting down the suicide rate in rural India.
Solar-cooling for rural milk centre
Refrigeration of milk-centres in rural India is very difficult as the rural part of the country is always power-starved. Majority of our agricultural products, which are perishable, are lost mainly because of poor power-supply. Rural agricultural products are lost either due to natural irregularities or non-availability of proper refrigeration facilities.
100% solar powered cold storage
Cold storage is vital for preserving perishable products like grapes, milk etc., and consumes lot of power. However, continuous failure-free electric power supply is very crucial throughout the year, especially during summer. Model COLDSOLAR/100 is a typical model from Solar Electronics, India, which is 100% powered by solar input of 100 sq.ft. area. The model consists cold storage roof top of solar panel, cold storage walls made up of sandwiched panels and solar powered compressor systems. The model varies from 100 to 1000 sq.ft. with cascading effect.
New evaporative solar cooling system
Introduction: There’s a world of difference between old-style swamp coolers and modern evaporative cooling systems. The latter can provide years of trouble-free service and cool, clean, comfortable, fresh air at a lower energy cost than conventional air conditioners _ and initial costs are competitive as well. In addition, the latest evaporative cooler designs are a lot easier. In addition to improved performance, modern evaporative coolers include options for thermostatic control and automated flushing of reservoir water to reduce buildup of impurities. Accordingly, wide-spread use of evaporative coolers can help delay in adding expensive new power plants to the electric grid _ and the controversial transmission lines that often accompany them. That’s the reason a number of utility companies in areas with hot, dry summers and substantial population growth have programmes to promote efficient evaporative coolers.
Evaporative cooling function
When air blows through a wet medium _ a tee shirt, aspen fibers (excelsior), or treated cellulose, fiberglass, or plastic _ some of the water is transferred to the air and its dry bulb temperature is lowered. The cooling effect depends on the temperature difference between dry and wet bulb temperatures, the pathway and velocity of the air, and the quality and condition of the medium.
Solar powered evaporative cooler
‘Direct’ evaporative coolers use a fan to pull outside air through media (pads) that are kept thoroughly wet by water that is sprayed or dripped on them (Figures 2 and 3). This filters the air and cools it. The water is typically delivered via tubes from a small pump, which draws from a reservoir below. The reservoir is replenished with tap water whose level is controlled by a float valve. The resulting fresh, cool, humidified air is blown into buildings _ where the pattern of flow (and cool air delivered) is determined by the location and extent of openings in the conditioned envelope _ such as windows or special dedicated ducts.
A typical Solar-Powered Evaporative Cooler From Solar Electronics, India, uses 100W/12V Solar-Panel & 12V/60AH battery (Model-SolaCool-SLR60). The total power – consumption of solar fan & water-pump is less than 60W. During daytime the cooler is directly powered online and during night powered by battery-bank. Additional LED bulb (12V DC/5W) also can be used on the same battery for minimum eight hours’ backup.
Modern evaporative coolers couple high performance media with low-velocity air flow. They maximise moisture transfer as the air traverses the media to enhance ‘direct saturation effectiveness,’ which is analogous to cooling efficiency. Direct evaporative cooler performance is measured relative to the wet bulb ‘depression.’ Well-designed systems with thick (10 to 12 inches or more) media operating properly can achieve 93% effectiveness.
