The recent concern about the state of the ozone layer and the raised concern on the effects of energy fuels on the environment have led to the use of non renewable sources of energy. Renewable sources of energy have a guarantee of continual provision of services as the energy can not be exhausted. The renewable sources of energy usually have no effects whatsoever on the environment. One major source of renewable energy is solar air. Solar air can be argued to be the cheapest source of energy as sunshine is freely available to mankind. Solar air systems can be classified in to unglazed air collectors and glazed air systems.
Unglazed air collectors
This refers to a solar system that is not laced with any glass at their tops. The metal absorbers of this type of solar air heating system are usually not covered with glazing over tops. The main type of the unglazed air collectors are the transpired air collectors. The system is mainly used in industrial and large business structures where the ventilation needs are high. The transpired solar air collectors are widely used due to their large solar conversion leading to large energy productions and are usually cheap to acquire.
Method of operation
The transpired solar air collector operates by using the air outside to provide heating needs of the house. The exterior region of the air collector is marked with perforations that create a negative pressure gradient in the interior of the house. The lower pressure gradient inside the house allows the solar air collector to draw in the air from outside a reasonable amount of pressure that heats the air. The resultant air inside the house is therefore relatively warmer providing a conducive interior temperature especially during the winter. The performance of the system can be noted precisely by the use of RET screen. You should however ensure that you have the most recent version of the RET screen as it is constantly updated to increase its accuracy depending on the condition.
Variations of transpired solar collectors
Unglazed solar air systems can be installed on top of roofs in cases where there are no suitable south facing walls. The heat obtained is directed from the roof through ducts or pipes to air controlling systems. The solar system can also be combined with photo voltaic pipes to result in a more effective solar air system. The combination of a photo voltaic panel with transpired solar air collector leads to the system operating at its stated efficiency of 250 ensuring an efficient heating process in the building.
Glazed air systems
This type of air system focuses on using re circulated air in a building to produce heat through the use of thermal and solar air collectors. The collectors trap the radiations from the sun and transfer them through ducts or pipes to the thermal air collectors in the interior of the house. The solar air collectors will transfer the heat from the ducts to the interior re circulated air through conduction. The heated air in the ducts is sourced from the exterior solar air absorbers. Collector types The varying air heating needs necessitates the existence of different types of air collectors for efficient functioning. These types of air collectors include through pass air collectors, front and combination air collectors
Through pass air collector back,
This type of glazed air system depends majorly on the conductive properties of the perforated materials in the duct of the air collector. The air inside the ducts is heated by the conductive nature of these materials. The air also receives supplementary heating from the convection heat that is brought about by the moving air. However extreme care should be taken in the management of this type of collector as they are usually exposed to deterioration leading to a compromise in the quality of services offered.
Back, front and combination passage air collector
This involves the passage of air through the front, the back or through the front and back of the ducts of the air collector. A combination of air passage through the back and front increases the surface area for heat absorption by the air in the ducts. However this type of solar air collector type requires keen maintenance practices as passage of air through the front of the duct can lead to a clog in the system. The system is therefore blocked from accessing the rays of the sun which are instrumental in its functioning.
Air heat applications
There are various applications of solar air heat devices. The devices can be used in space heat applications and a variety of other heating applications. This includes their use in green house gases to optimize the temperature conditions of the green house to favor the crops grown. The solar air heating systems are also combined with photo voltaic panels to improve their efficiency by ensuring that the panels do not heat up during their use.
Space heat application
This involves the use of the solar air heating devices to modify the interior temperature conditions to attain desired warm conditions. The solar air heating devices in this case are used especially during the cold period. The devices use the air from the interior of the building or air sourced from the ambient to provide the required heating for the house. The sourced air is then heated by either conduction from the material of the ducts or convection from the surrounding air. Usually these solar air devices are placed in south facing walls to enhance their efficiency in heating service provision.
A benefit of using these solar air heating devices is that they are usually environment friendly in nature. The functioning of the solar air collectors does not entail the emission of any harmful chemicals in the environment. Furthermore the systems provide a sure way of continuous provision of heating to the house as it uses a non exhaustible source of energy, the sun. This also makes the use of these devices relatively cheap as there are no utility bills that are associated with the use of solar heat energy. A building is therefore assured of an efficient interior heat provision at a relatively low price.