Air Conditioning Quiz

1. 1. Principles of cooling

   Heat is a form of energy and every object on earth has some heat energy. The less heat an object has, the colder we say it is. Cooling is the process of transferring heat from one object to another. When an air - conditioning system cools, it is actually removing heat and transferring it somewhere else. There are two forms of heat energy: sensible heat and latent heat. Sensible heat is the form of heat energy which is most commonly understood because it is sensed by touch or measured directly with a thermometer. Latent heat cannot be sensed by touch or measured with a thermometer. Latent heat causes an object to change its properties.

2. 1. ...............is the form of heat energy which is sensed by touch or measured directly with a thermometer.

• Latent heat

• Sensible heat

• Radiant heat

• Geothermal

2. 2. Change of state

   An object that changes from a solid to a liquid or liquid to vapor is referred to as a change of state. When an object changes state, it transfers heat rapidly.

   Humidity

   Moisture in the air is called humidity. The ability of air to hold moisture directly relates to its temperature. The warmer air is, the more moisture it is capable of holding. Relative humidity is the percentage of moisture in the air compared to the amount of moisture it can hold. Humidity is also a form of latent heat. When air contains more humidity, it has more latent heat.

   Refrigerant

   Refrigerants are substances used by air conditioners to transfer heat and create a cooling effect. Air - conditioning systems use specially formulated refrigerants designed to change state at specific temperatures providing optimum cooling.

3. 2. Air - conditioning systems use specially formulated ........... designed to change state at specific temperatures providing optimum cooling.

• sensible heat

• water

• refrigerants

• vapour

3. B. Air - conditioning Systems:

   In general, all air - conditioning systems have four major components, including: compressor, condenser, metering device and evaporator. Refrigerant is drawn from the evaporator and pumped to the condenser by the compressor. The compressor also pressurizes the refrigerant vapor so that it will change state (condense) readily. The high - pressure refrigerant vapor releases heat through the condenser coils as it condenses into liquid refrigerant which makes it easier to vaporize. The metering device restricts the flow of liquid refrigerant from the condenser to the evaporator. As refrigerant passes through the metering device, its pressure decreases. The low - pressure liquid refrigerant absorbs heat as it vaporizes in the evaporator coils.

4. 3. As refrigerant passes through the metering device, .................... pressure decreases.

• the condenser's

• the evaporator's

• the metering device's

• the refrigerant

B. Air - conditioning Systems:

In general, all air - conditioning systems have four major components, including: compressor, condenser, metering device and evaporator. Refrigerant is drawn from the evaporator and pumped to the condenser by the compressor. The compressor also pressurizes the refrigerant vapor so that it will change state (condense) readily. The high - pressure refrigerant vapor releases heat through the condenser coils as it condenses into liquid refrigerant which makes it easier to vaporize. The metering device restricts the flow of liquid refrigerant from the condenser to the evaporator. As refrigerant passes through the metering device, its pressure decreases. The low - pressure liquid refrigerant absorbs heat as it vaporizes in the evaporator coils.

4. 4. ....... absorbs heat as it vaporizes in the evaporator coils.

• the low - pressure refrigerant vapor

• the high - pressure refrigerant vapor

• the high - pressure refrigerant vapor

• the low - pressure liquid refrigerant

5. 2. Change of state

   An object that changes from a solid to a liquid or liquid to vapor is referred to as a change of state. When an object changes state, it transfers heat rapidly.

   Humidity

   Moisture in the air is called humidity. The ability of air to hold moisture directly relates to its temperature. The warmer air is, the more moisture it is capable of holding. Relative humidity is the percentage of moisture in the air compared to the amount of moisture it can hold. Humidity is also a form of latent heat. When air contains more humidity, it has more latent heat.

   Refrigerant

   Refrigerants are substances used by air conditioners to transfer heat and create a cooling effect. Air - conditioning systems use specially formulated refrigerants designed to change state at specific temperatures providing optimum cooling.

6. 5. Which is the percentage of moisture in the air compared to the amount of moisture it can hold?

• relative humidity

• very low humidity

• high humidity

• low humidity

5. Air Conditioning

   The history of an invention that makes life more pleasant

   Willis Carrier designed the first air-conditioning unit in 1902, just a year after graduating from Cornell University with a Master’s in Engineering.

   At a Brooklyn printing plant, fluctuations in heat and moisture were causing the size of the printing paper to keep changing slightly, making it hard to align different colours. Carrier’s invention made it possible to control temperature and humidity levels and so align the colours. The invention also allowed industries such as film, processed food, textiles and pharmaceuticals to improve the quality of their products.

    

   1. When Willis Carrier invented air conditioning, his aim was to ___________

• make workers feel cooler.

• produce more attractive paper.

• set up a new business.

• solve problems in a factory.

5. Air Conditioning

   The history of an invention that makes life more pleasant

   Willis Carrier designed the first air-conditioning unit in 1902, just a year after graduating from Cornell University with a Master’s in Engineering.

   At a Brooklyn printing plant, fluctuations in heat and moisture were causing the size of the printing paper to keep changing slightly, making it hard to align different colours. Carrier’s invention made it possible to control temperature and humidity levels and so align the colours. The invention also allowed industries such as film, processed food, textiles and pharmaceuticals to improve the quality of their products.

6. In 1914, the first air-conditioning device was installed in a private house. However, its size, similar to that of an early computer, meant it took up too much space to come into widespread use, and later models, such as the Weathermaker, which Carrier brought out in the 1920s, cost too much for most people. Cooling for human comfort, rather than industrial need, really took off when three air conditioners were installed in the J.L. Hudson Department Store in Detroit, Michigan. People crowded into the shop to experience the new invention. The fashion spread from department stores to cinemas, whose income rose steeply as a result of the comfort they provided.

7. 2. Home air conditioners were not popular at first because they were ___________

• 5. too big and expensive.  

• 5. not considered necessary.    

• 5. too inefficient.

• 5. complicated to use.

5. Air Conditioning

   The history of an invention that makes life more pleasant

   In 1914, the first air-conditioning device was installed in a private house. However, its size, similar to that of an early computer, meant it took up too much space to come into widespread use, and later models, such as the Weathermaker, which Carrier brought out in the 1920s, cost too much for most people. Cooling for human comfort, rather than industrial need, really took off when three air conditioners were installed in the J.L. Hudson Department Store in Detroit, Michigan. People crowded into the shop to experience the new invention. The fashion spread from department stores to cinemas, whose income rose steeply as a result of the comfort they provided.

   To start with, money-conscious employers regarded air conditioning as a luxury. They considered that if they were paying people to work, they should not be paying for them to be comfortable as well. So in the 1940s and ’50s, the industry started putting out a different message about its product: according to their research, installing air conditioning increased productivity amongst employees. They found that typists increased their output by 24% when transferred from a regular office to a cooled one. Another study into office working conditions, which was carried out in the late ’50s, showed that the majority of companies cited air conditioning as the single most important contributor to efficiency in offices.

6. 3. Employers refused to put air conditioning in workplaces at first because they_________

• 5. could not afford to pay for it.   

• 5. thought it was more suitable for cinemas.      

• 5. did not want to spend money improving working conditions.      

• 5. thought people would not work so hard in comfortable conditions.

5. Air Conditioning

   The history of an invention that makes life more pleasant

   In 1914, the first air-conditioning device was installed in a private house. However, its size, similar to that of an early computer, meant it took up too much space to come into widespread use, and later models, such as the Weathermaker, which Carrier brought out in the 1920s, cost too much for most people. Cooling for human comfort, rather than industrial need, really took off when three air conditioners were installed in the J.L. Hudson Department Store in Detroit, Michigan. People crowded into the shop to experience the new invention. The fashion spread from department stores to cinemas, whose income rose steeply as a result of the comfort they provided.

   To start with, money-conscious employers regarded air conditioning as a luxury. They considered that if they were paying people to work, they should not be paying for them to be comfortable as well. So in the 1940s and ’50s, the industry started putting out a different message about its product: according to their research, installing air conditioning increased productivity amongst employees. They found that typists increased their output by 24% when transferred from a regular office to a cooled one. Another study into office working conditions, which was carried out in the late ’50s, showed that the majority of companies cited air conditioning as the single most important contributor to efficiency in offices.

6. 4. What was the purpose of the research done in the 1940s and ’50s?

• 5. to make office workers produce more

• 5. to compare different types of air conditioner      

• 5. to persuade businesses to buy air conditioners  

• 5. to encourage employees to change offices

5. Air Conditioning

   The history of an invention that makes life more pleasant

   ...

   To start with, money-conscious employers regarded air conditioning as a luxury. They considered that if they were paying people to work, they should not be paying for them to be comfortable as well. So in the 1940s and ’50s, the industry started putting out a different message about its product: according to their research, installing air conditioning increased productivity amongst employees. They found that typists increased their output by 24% when transferred from a regular office to a cooled one. Another study into office working conditions, which was carried out in the late ’50s, showed that the majority of companies cited air conditioning as the single most important contributor to efficiency in offices.

6. However, air conditioning has its critics. Jed Brown, an environmentalist, complains that air conditioning is a factor in global warming. Unfortunately, he adds, because air conditioning leads to higher temperatures, people have to use it even more. However, he admits that it provides a healthier environment for many people in the heat of summer.

7. 5. What does Jed Brown say about air conditioning?

• 5. In future, everyone will need it.    

• 5. Turning it off will not reduce global warming.  

• 5. It can seriously damage people’s health.

• 5. It is good for people, but bad for the environment.