Solar collectors Water and Air “Solar Farms”
There are many types of solar collectors and many forms of divisions and categories
- parabolic – focusing
- rotary – tracking the sun
The technology of manufacture and the type of the collector have an impact on the efficiency and performance , insulating medium , deviation of the heat transfer element to the entire surface of the collector .
We’ll take care division at medium receiving heat from the collector :
- solar collectors for water ( fluid flowing through the collector is antifreeze fluid )
- air solar collectors ( collector cooling agent is atmospheric air )
Solar collectors are a free source of heating energy , However, quite a lot of cost . When planning investment of solar collectors should take into account at least 10 – 15 years .
When designing the placement of the collectors should be considered as natural shading trees (which are growing), buildings on adjacent plots and possible convenience for service and installation.
It should take into account the fact that in the summer the sun shines into much greater account in relation to the earth’s surface in the winter so the same obstacle can thwart the use of collectors casts a shadow . In the case of large plots of land , eg . agricultural , You can install solar panels on the ground – on the north side of the plot , because we manage the layout of buildings and trees on home soil . Installing collectors on earth takes place , however:
- allows their easy service (periodic cleaning)
- adjusting vertical inclination in relation to the season
- obscure if we do not have an alternative cooling circuit in the summer when we go on vacation
- energy losses proportional to the distance from the heated space
Deciding on the collectors on the roof need to be taken into account when planning the building structure , shape of the roof , so that the slope for the installation of collectors was on the south side , we can derive from it the greatest profits .
When mounting the collectors on the roofs must take into account the need for maintenance and cleaning , especially when we burn solid fuels in the house (boilers , fireplaces) and to the collectors can accumulate a lot of soot.
Especially in the case of old farms , with large parcels recommend that you install the collectors on the ground.
If we can not or do not want to install the collectors directly on the ground , You can think about the execution of shelters or the woodshed for the installation of solar panels on their roof . When designing these factors should be taken into account .
Solar collectors Air
In these collectors Solar heat receiving medium is ordinary atmospheric air or other gas closed loop . They have a much lower yield with respect to the water because of the 20 times lower rate of heat transfer through the air towards water , causing the energy source is a low-temperature heating . Not suitable for heating water .
They are ideal for heating foundations , empty air space (eg between polystyrene and heat-insulating building outside , the gypsum – cardboard inside the building) . Despite the low temperature air (20 – 40C ) have a number of advantages with optimal use of the available space heating :
- draining the walls of the building , mineral wool with dew and water vapor – the polystyrene , Plasterboard – cardboard and roof , reducing the heat exchange coefficient of construction materials and reducing the heat loss through thermal bridges
- counteract the walls acting to freeze their pre-heating from the outside
- significantly limit the escape of energy from the building through free heating is the biggest loss -generating elements such as roofs , bevels , wall
- are simple and cheap to execute and obtain such . downloading the hot air from the metal roofing – tiles on the roof of the world , Garage , buildings and fans crowding them into the heated space
- allow free heating or pre-heating your basement rooms , garage , greenhouse , etc. . while ensuring their proper ventilation by forcing air circulation
A very simple example of a cheap and effective ” air collector ” made yourself:
Founding roof made of metal roofing – tiles placed on the formwork full . Roof with minimal sun shining through the clouds even heats up , heating the space between the metal roofing – tiles and full roof truss formwork . Even in the case of the February frosts of up to minus 20 degrees ( winter frosts (daily ) are in full sun and lack of cloud cover ) . On cloudy days the clouds prevent freeze form ” goose-down comforter ” over the area, so there is a relatively high temperature .
In winter, on sunny days , despite the cold weather outside , roof heats up to 40 – 50 degrees . Heat is normally escapes irretrievably up through the roof ridge . To use this heat must be reversed gravitational pull of air between the metal roofing – tiles and boarding sucking the air with the help of miniature fans such as computer to 12V .
In the attic of a full boarding the ridge cut at 2m hole with a diameter of about 10cm or less at 1mb .
distribute ventilation pipes in the insulation between these holes and the places that we want to heat (it can be , for example, the northern wall of the building – the space between the polystyrene and the wall ) at the bottom of the wall at the same distance installing extractor fans miniature cooled down by cold air outside wall . In this system, we use the free energy heating up the roof to heat the northern part of the building , which is the coldest . In addition, it is drained dry and warm air . We use here every year thousands of kilowatts of heat energy , which escapes irretrievably into the ether , and it can work for us for free .
Of course, such a system has only a sense of ensuring control Fan independently measuring the temperature directly in the heated intake air .
It is necessary to use this roomManager , which allows you to heating control for 7 independent heating zones as programmed . The controller automatically turns on when you set up each fan , independently by measuring with an associated temperature sensor , pulling cold air from outside the building (or unheated garage) , thereby sucking warm from the heated metal roofing – tiles . After cooling air under the metal roofing – tile fan is automatically switched off by the microprocessor controller . The fan will only when heated in air under metal roofing – tile
This driver is part of the Smart Home , intelligent Building eHouse .
Temperature threshold on and off the fan is set individually for each measurement input .
the work of this ” air collector ” also has a sense of summer , drying the walls and energy accumulating in the walls of a building which in regard to the annual demand for energy will contribute to significant savings in periods of transition and during the heating season . Drying buildings reduces heat loss (decreases the permeability of heat ) , prevents the formation of fungi , mold , musty smell, allergens which makes the building less healthy and require frequent repairs .
In aqueous medium solar collectors heat sink ( the energy produced by the sun’s rays ) is a non-freezing liquid . This may be a mixture of water with antifreeze concentrate ( eg radiator fluid ) based on glycol or other chemical . They have a much higher efficiency of air collectors and can give much higher temperatures . During the transitional periods ( spring , fall) and summer depending on weather conditions , can fully meet the demand for home heating and water heating , the relatively small area of less than 10m2 for a single family house with an area of 200m2 . To use efficiently the energy from the collectors of water is necessary to its storage in buffers of hot water with a capacity dependent on the active surface of the collector . In addition, due to the high efficiency , it is necessary to protect the collector from overheating when no receipt of hot water ( e.g., the leaves , summer trips , power failure , etc. . ) .
In these situations it is necessary to ensure the collection ( pump emergency power supply UPS to ensure continuous operation ) and alternative coolant circuit to dissipate unused solar heat collector . For this purpose, it is useful to make a heat exchanger ( tube for floor heating ) providing heat removal , in situations where a long time has no energy or hot water heater . Some installations in such a case will automatically open the solenoid spilling hot water into drains , However, there are several hundred kilowatts , which could be used in a more useful way .
Surplus energy from the solar water can be used for thermal energy storage material with high thermal inertia such as concrete , whether the land directly under the foundation .
Heating tens of cubic meters of concrete block building with a few degrees will reduce spending on heating at a later date . In the case of heating of the baseplate or the ground directly under the floor due to the very high thermal inertia , allows the use of this energy in a few weeks , reducing the aggregate annual energy consumption of heating and the subsequent escape of heat into the ground , due to thermal bridging or foundation slab foundation .
To make the most of this energy can also heat the concrete elements of the house as stairs , ceilings , poured concrete walls , basement floor , garage . In order to use this energy is required during the construction phase distribution of water coils (pipes for floor heating ) in areas where we intend to store the energy . Before moving on to the next stages of construction it is necessary to check their tightness . In case of damage or loss of containment this coil when building a house , or a time , Unfortunately, it is not for use and must be switched off so as not to flood the house or foundation .
The use of energy storage within the building should also be carried out with the head providing them with Automatic control and distribution in the place where the lowest temperature .
It is necessary to use this driver to peace , which allows you to heating control for 7 independent heating zones as programmed . Driver when configured automatically open each solenoid coil for a given segment , independently by measuring with an associated temperature sensor ( floor or concrete ) , and heating it to the desired temperature .
When heated to a preset temperature controller closes the solenoid valve that section ” underfloor heating ” directing the fluid from the collectors to the other heating section . After cooling, the block of concrete to set temperature lower microprocessor controller re- open the solenoid valve allowing further heating and energy storage . These operations are performed automatically and independently for each segment of the heating control .
When using a large number of solar collectors of this type of control and favorable climatic conditions and weather can get coverage of the order of 60% – 70% demand for home heating and hot water throughout the year .
This term conceals objects containing a large amount (area) of any type of solar collectors . These could be farms or other outbuildings , where a large percentage of the demand for heating is from solar collectors . In some cases, the efficiency of the collector is not critical and may be much more advantageous to apply a little more efficient collectors of the active area but much cheaper . Such applications may include reheating and heating the greenhouse , conservatories , economic facilities , Grocery stores where we do not have to maintain room temperature , and only the positive temperature while ensuring good ventilation .
The effective area farms solar collectors is calculated redundantly to ensure a high percentage of cover demand at 85%-90% year-round energy . During the over- heating energy is dissipated or stored in large tanks , pools , ponds , or soil in greenhouses, partly by reducing the need for additional heating in winter . For the storage of solar energy ( heat ) is used for some time to gel-filled buffer , which can store about 16 times more energy in relation to water , for the same unit volume . The farms of solar collectors in the months of the overproduction of energy can be obscured manually
automatically controlled or by the system control blinds , awnings , blinds or put neighboring farms or objects . home automation and building eHouse