The main purpose of thermal insulation of a building’s heat insulation is to preserve a constant heat or temperature inside the building, even if the outside temperature changes.
Heat in a building structure is mainly transmitted through roofs, exposed walls and exposed wall openings, such as windows, doors, ventilators, etc. and accordingly the commonly adopted methods of heat insulation are as follows:
- Methods of heat insulation of roofs
- Methods of heat insulation of exposed walls
- Methods of insulation of open windows, doors and ventilators etc.
1. Methods of heat insulation of roofs
From the point of view of comfort it is desirable that the thermal transmittanceYou‘ of exposed roofs should not exceed 2k.cal. per square meter2 h0C. Hence, ‘methods are adopted to reduce the excess’You‘ Value by treating the roofs. The following methods of thermal or heat insulation are commonly employed for the treatment of interior and exterior surfaces.
- The described heat insulating material is applied externally to the roofs. In the case of outdoor use, the heat insulating material can be installed on the roof, but under a waterproof course. In the case of internal use, the heat insulating material may be fixed to the undersides of the roofs from within the rooms, with adhesives or otherwise.
- A false ceiling of insulating material can be provided under the ceiling with an air gap in between.
- Glossy and reflective insulation materials can be installed or placed on top of the roof.
- An air space can be created over flat roofs by arranging sheets of asbestos cement or corrugated galvanized iron over the bricks.
- Flat roofs can be kept cool from flood water either by storing them or by spraying them regularly. This helps in reducing the outside temperature significantly. In such cases water loss due to evaporation can be compensated by installing make-up arrangements.
- Whitewashing the ceiling before the start of each summer also helps with heat insulation.
- Appropriate shading of ceilings on exposed surfaces also lowers surface temperatures.
2. Methods of heat insulation of exposed walls
For walls, even taking into account comfort, it is desirable to have thermal transmission (You) 2 k.cl per m of exposed walls. not more than2 h0c. In order to achieve this objective the following methods are adopted for thermal insulation of exposed walls:
- The thickness of the walls can be increased depending on the extent of the derived insulation.
- Hollow wall or cavity wall construction can be adopted.
- Walls can be constructed from suitable heat-insulating materials provided the structural requirements are met.
- A variety of heat insulating materials can be installed or fixed inside and outside the exposed wall to reduce thermal transmission to the desired extent. In case of outdoor use, overall water proofing should be done.
- For partition walls, an air space can be created by fixing sheaths of rigid boards or battens to either side of the walls.
- A light colored white-wash or distemper can be applied to the exposed surface of the wall to increase the thermal insulation value.
3. Methods of thermal insulation of exposed windows, doors, ventilators etc.
All windows, doors, ventilators etc that are exposed transmit heat to a great extent. The following methods can be suitably used to achieve heat insulation of exposed windows, doors etc.
Reduction in incidence of solar heat
The incidence of solar heat on open doors and windows can be reduced in the following ways:
- Using outdoor shading, such as louvered shutters, sun breakers and balconies or weather sheds.
- Adopting internal shading, such as heavy folding curtains, Venetian blinds, etc.
reduction in heat transmission
Where glazed windows and doors are provided, a reduction in heat transmission may be achieved by insulating the glass or double glass with air space in between or by some other suitable medium.