10. Insert the right words.
a) egress b) steam c) electrical wiring d) moisture e) power failures
1. Most houses are heated by warm air, … or hot water.
2. The air must not be too warm or too cool, and it must have the right amount of …
3. …is the system of wires and cables that distributes electricity throughout a building.
4. Emergency power generators are installed in an increasing number of buildings to compensate inconvenience of …
5. For fire protection, it is necessary to provide at least two means of …
11. Make a short summary of the text. Do it according to the following plan.
1. The title of the text is…2. The text is devoted to …3. It consists of …4. The first passage deals with…5. The second (third, forth, etc.) passage deals with…6.The main idea of the text is…
Text b. Insulation for Heat Flow Control
Skim the text and answer the questions below.
Thermal insulation is the most effective means of conserving energy and reducing its cost. It is accomplished by enveloping the house with a layer of insulating material.
In homes and other buildings, insulation prevents heat from passing out of the structures during cold weather or into the structures during hot weather.
Materials used for insulation include fibreglass, metal foil, rock wool fibres, and certain plastics. These materials are poor conductors of heat. When placed against a heated surface, they provide a barrier to the flow of heat. In addition, most insulation materials consist of fibres with cell-like spaces that block the motion of hot or cold air.
In buildings insulation is installed in the areas where the greatest heat loss occurs. In most homes, these areas are the attic floor, the ceiling of an unheated basement, and the side walls. Insulation for the side walls is installed in the space between the interior and exterior walls. If a basement is heated, its side walls should be insulated.
There are five chief kinds of insulation for buildings: (1) batts and blankets, (2) loose-fill insulation, (3) cellular plastics, (4) rigid insulation boards, and (5) reflective insulation.
Insulation for heat control prevents heat from flowing through ceilings and walls to unheated parts of a house or to the outside. The insulation should be installed in the areas where such heat loss could occur.
Batts and blankets are soft, flexible units made of fibreglass and rock wool fibres. Batts are cut to certain sizes by the manufacturer. Blankets are sold in long rolls that can be cut to any size during installation. Batts and blankets are used between the joists, the beams that support the floor and ceiling, and between wall studs, which make up the vertical part of the building frame.
Loose-fill insulation consists of short fibres of cellulose, fiberglass, perlite, rock wool, or vermiculite. It is used chiefly in attics and side walls. Loose-fill insulation can be blown or poured into attics. It is installed between the interior and exterior walls by blowing it through small holes in one of the walls.
Cellular plastics are used to make plastic foam boards, which can be attached to a finished wall. These plastics are also used to make an insulating foam that can be injected into finished walls.
Rigid insulation boards are made from such materials as fibreglass, gypsum, and perlite. They can be attached to the ceiling, roof or walls.
Reflective insulation consists of thin sheets of aluminium foil. The sheets are arranged in layers separated by spaces that trap warm air. Reflective insulation is used between the joists and between wall studs.
Almost all insulation needs a vapour barrier to prevent moisture from penetrating the insulation and decreasing its effectiveness. A vapour barrier can be a sheet of foil, plastic, or treated paper. It must be put on the side of the insulation that faces the heated area.
The effectiveness of an insulation material is designated by its R-value, a measurement of the material's resistance to the flow of heat. Materials with high R-values have the greatest heat flow resistance.
Insulation should be fireproof and able to resist any physical or chemical changes that could reduce its effectiveness. It should also be resistant to destructive small animals, such as insects, mice, and rats.
Notes:
fibreglass – стекловолокно
perlite – перлит
plastic foam – пенопласт
vapour barrier - пароизоляция, паронепроницаемый слой
1. What does insulation prevent?
2. What do the materials used for insulation include?
3. What are five chief kinds of insulation for buildings?
4. Where are batts and blankets used?
5. What does loose-fill insulation consist of?
6. What are cellular plastics used to make?
7. What are rigid insulation boards made from?
8. Where is reflective insulation used?
9. What is R-value?