47.Read the texts of Unit 3 again and make notes under the following headings. Then use your notes to talk about Ventilation.

1) Broad definition of Ventilation and basic approaches to it (spot and general).

2) Ventilation methods (natural and power).

3) Whole-house ventilation systems’ classification (exhaust, supply and balanced):

-equipment needed,

- appropriate climates,

-disadvantages.

REVIEW_____________________________Check Your Knowledge

1.Match the terms with their definitions:

1) a fan	a) a device or an opening for letting fresh air come into a room, etc.
2) ventilator	b) when a liquid, gas, or air moves continuously around a place or system
3) to exhaust	c) a machine with blades that go round to create a current of air
4) heat exchanger	d) operated by power from an engine
5) bacteria	e) a machine that is used to force liquid, gas or air into or out of sth.
6) to circulate	f) the amount of water in the air
7) mechanical	g) waste gases that come out of a vehicle, an engine or a machine
8) a damper	h) a piece of metal that can be moved to allow more or less air into a fire so that the fire burns more or less strongly
9) a pump	i) a device for making heat pass from one liquid to another without allowing the liquids to mix
10) humidity	j) the simplest and smallest forms of life, exist in large numbers in air, water and soil, and also in living and dead creatures and plants, and are often a cause of disease

2. Choose the best option.

1) There are … basic approaches to ventilating a house.

a) two

b) three

c) four

2) Three basic functions of ventilation are …

a) to replace the used air, to cool, to heat

b) to remove products of combustion, to heat, to low pressure

c) to replace the used air, to avoid humidity, to prevent dust accumulation

3) Spot ventilation is used …

a) for sources that can move from place to place

b) for localized sources

c) for industrial purposes

4) General ventilation runs …

a) when the source is producing pollutants

b) when needed

c) continuously

5) Cooking odors can be removed by …

a) spot ventilation

b) exhaust fan

c) both

6) Natural ventilation depends on … critically.

a) house localization

b) size and localization of openings

c) pressure differences

7) Natural ventilation is ineffective in … climates.

a) cold

b) hot

c) humid

8) Main advantage of power ventilation is …

a) cost effectiveness

b) providing ventilation anytime

c) providing limited attic temperature

9) Wholehouse ventilation systems have … main types.

a) two

b) three

c) four

10) System of ventilation appropriate for all climates is …

a) supply and exhaust system

b) balanced ventilation system

c) balanced, heat-recovery ventilation system