FIELD OF INVENTION
The present invention relates to a system of passive cooling and heating for building integrated photovoltaic (BIPV) building. More particularly, the invention relates to a system of minimizing the heat generated by solar laminates under sunlight in summer and utilizing the same heat during winter for a room of BIPV building.
BACKGROUND AND PRIOR ART OF THE INVENTION
The system designed and developed in this invention would find use in PV/semiconductor industry for designing and making of building integrated photovoltaic (BIPV) buildings. It provides a simple alternative to the expensive cooling /heating mechanism that normally forms a part of the building. This results in saving of a large sum of money in construction of BIPV buildings. With this mechanism, proper cooling and heating can be achieved for BIPV using natural air flow arrangement.
The removal of heat from the solar modules has not been attempted much even though the problem can severely affect the performance of the BIPV system and the comfort level of the persons sitting inside the BIPV building. The passive cooling mechanism has been suggested for small systems such as designing a

heat shield mechanism for housing of a power source (US7480145) using passive cooling or transpiration cooling for ultra mobile computers (US7463486). Therefore, it is the objective of the invention to provide a less expensive system for heat removal from the solar modules using passive cooling. Further, the heat can also be utilized for heating of the room during winter.
OBJECTS OF THE INVENTION
Therefore it is an object of the invention to propose a system of passive cooling and heating for building integrated photovoltaic building which can be adapted as an alternative to the normal expensive cooling and heating of a building.
Another object of the invention is to propose a system of passive cooling and heating for building integrated photovoltaic building which utilizes natural cooling/heating concept.
SUMMARY OF THE INVENTION
This invention relates to a passive cooling/heating of building integrated photovoltaic (BIPV) building. When solar laminates generate electricity it also generates heat due to the increase in the temperature of the solar laminate under sunlight. This excess heat has to be minimized or taken away in summer and utilized meaningfully in winter. To reduce heat generated by solar laminates

and other object installed in the roof along with laminate, passive cooling windows with wire mesh are provided above the false roofing in northern and southern side of BIPV building. These wire mesh windows are provided just below the roof and above false ceiling. These windows allow fresh air to enter from the lower side and exit from the higher side helping in reducing the excessive heat in the process.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Fig.l - shows an isometric view of passive cooling/heating system of BIPV building according to invention.
Fig.2 - shows a side view of passive cooling/heating system of BIPV building according to invention without solar laminates.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION
A BIPV room has been designed and constructed at BHEL, ASSCAP, Gurgaon. The room has been designed to function as a small office such that the solar module laminates generate sufficient power to meet its energy needs. Special care on safety has been taken while constructing the BIPV room, having false roofing, tilted roof with SPV laminates and RCC pathways for maintenance purpose. The room is also provided with tilted windows having solar laminates to

get better performance. This BIPV room has most of the green building features like passive cooling and heating, power efficient lighting system etc. Passive cooling/heating system maintains the comfortable atmosphere in the room in various seasons and the room requires minimum electric power to maintain the comfort level.
The invention describes a passive cooling/heating system for BIPV building. It comprises of windows with wire mess on the northern as well as southern side, false roofing and other greenhouse features. It enables the entering of natural air through multiple windows from the lower side and exit of the hot air through multiple windows from the top. Wire mesh provided in the windows prevents the entrance of the foreign objects and false roofing is also provided for further insulation. Green house effect has been used for passive heating during winter season. Arrangement has been made to block the wire mesh opening during winter, which keeps the room hot. On southern side, inside area near the tilted windows has been made as a closed enclosure with sliding door as a partition with room.
The passive cooling/heating system for BIPV room works on the principle of natural circulation of air and the green house effect. As shown in Fig.l opaque and semi transparent solar laminates (1) are incorporated in the roof of the building, these work as roof for building and generate electric power. When solar laminates generate electricity it also generates heat due to the increase in the

temperature of the solar laminate under sunlight. This excess generated heat has to be minimized or taken away for cooling purpose and while for heating it need to be utilized meaningfully. False ceilings (4) are incorporated in building to isolate the atmosphere between room and solar laminates. Multiple passive cooling wire mesh windows (3) are incorporated in the northern side of the building between the false ceiling and roof made of solar laminates. Passive cooling windows (2) are incorporated in the southern side of the building between the false ceiling and roof made of solar laminates. As the level of the windows (3) is higher than the windows (2), the natural air flows from windows (2) to windows (3). The windows (2) enable the entry of natural air from the lower side and multiple passive cooling windows (3) enable exit of the hot air from the top side. Wire mesh provided in the windows prevents the entry of the foreign objects inside the room while the false roofing (4) further isolate room atmosphere to the atmosphere between solar laminates and the false roofing. Green house effect has been used for passive heating during winter season. Arrangement has been made to block the wire mesh opening during winter, which keeps the room hot. On southern side, inside area near the tilted windows has been made as a closed enclosure with sliding door as a partition with room.

WE CLAIM
1. A system of passive cooling and heating for building integrated
photovoltaic building comprising:
a plurality of opaque and semi transparent solar laminates (1)
incorporated on the roof of the building generating heat during generation
of electric power;
false ceilings (4) incorporated in the building for isolating the atmosphere
between room and solar laminates (1);
a plurality of passive cooling wire mesh windows (3) provided in the
northern side of the building between the false ceilings (4) and roof made
of solar laminates (1);
a plurality of passive cooling windows (2) provided in the southern side of
the building between the false ceiling (4) and the roof made of solar
laminates (1);
characterised in that the level of the windows (3) being higher than the
windows (2) the natural air flows from windows (2) to windows (3)
reducing the excessive heat in the process during summer for maintaining
a comfortable atmosphere in the room.
2. A system of passive cooling and heating as claimed in claim 1, wherein
the windows (2) allow natural air to flow from lower side and windows (3)
allow hot air to exit from the top side.

3. A system of passive cooling and heating as claimed in claim 1, wherein wire mesh openings are blocked during winter for keeping the room hot.
4. A system of passive cooling and heating as claimed in claim 1, wherein sliding door partition near the tilted windows utilizes green house effect during winter.
5. A system of passive cooling and heating as claimed in claim 1 to 5, wherein wire mesh are provided in the windows (2,3) for preventing unwanted foreign objects entering into the building.

A system of passive cooling and heating for building integrated photovoltaic building discloses a plurality of opaque and semi transparent solar laminates (1) are incorporated on the roof of the building when said laminates (1) generate heat during generation of electric power. False ceilings (4) are incorporated in the building for isolating the atmosphere between room and solar laminates (1). A plurality of passive cooling wire mesh windows (3) are provided in the northern side of the building between the false ceilings (4) and roof made of solar laminates (1). A plurality of passive cooling windows (2) are provided in the southern side of the building between the false ceiling (4) and roof made of solar laminates (1). Level of windows (3) being higher than the windows (2), the natural air flows from windows (2) to windows (3) reducing the excessive heat in the process during summer for maintaining a comfortable atmosphere in the room. During winter wire mesh opening are blocked which keeps the room hot.