Lesson 4 How Does Air Conditioning Work? Part 3

Compressor Relief Valve

Some compressors have a relief valve for regulating pressure. If the system discharge pressure exceeds rated pressure, the valve will open automatically and stay open until the pressure drops. The valve will then close automatically.

Compressor Noise Complaints

Many noise complaints can be traced to the compressor mount and drive. If a unit is noisy at one speed and quiet at another, it is not compressor noise. Many times this kind of noise can be eliminated or greatly reduced by changing the belt adjustment.

Usually tightening mounts, adding idlers, or changing belt adjustment and length are more successful in removing or reducing this type of noise, than replacing the compressor.

Noises from the clutch are difficult to recognize because the clutch is so close to the compressor. A loose bolt holding the clutch to the shaft will make a lot of noise. The difference, between suction pressure and discharge pressure, also plays an important part on sound level. A compressor with low suction pressure will be more noisy than one with a higher pressure.

Consider whether the system is properly charged, whether the expansion valve is feeding properly to use the evaporator efficiently, and whether enough air is being fed over the evaporator coil.

Air Conditioner Filters

The most important maintenance task that will ensure the efficiency of your air conditioner is to routinely replace or clean its filters. Clogged, dirty filters block normal airflow and reduce a system’s efficiency significantly. With normal airflow obstructed, air that bypasses the filter may carry dirt directly into the evaporator coil and impair the coil’s heat-absorbing capacity. Filters are located somewhere along the return duct’s length. Common filter locations are in walls, ceilings, furnaces, or in the air conditioner itself.

Some types of filters are reusable; others must be replaced. They are available in a variety of types and efficiencies. Clean or replace your air conditioning system’s filter or filters every month or two during the cooling season. Filters may need more frequent attention if the air conditioner is in constant use, is subjected to dusty conditions, or you have fur-bearing pets in the house. If you use a disposable type filter, it’s always wise to keep several spares inside the house.

Vocabulary

relief valve – спускной клапан, клапан сброса давления

discharge pressure - давление на выходе

mount – детали крепления, опора, установочное приспособление, зажим, крепление,  

idler - поддерживающий ролик, промежуточная шестерня, холостой шкив или блок

shaft – вал, привод, ось,

suction pressure - давление на входе в насос

reusable [,ri:’ju:z(ə)bəl]- многоразовый

duct – трубка, проход, канал

return duct – обратный канал

Exercise 1

Find Russian equivalents to the following words in the text. Learn them by heart.

Превышать, допустимый, подвинчивать, узнать/распознать, уровень, ослабленный/незатянутый, обеспечивать, засоренный, блокировать, преграждать/затруднять, проходить мимо, трубка/канал, многоразовый, рассматривать/учитывать, заряжать, заменять, многообразие чего-то, одноразовый

Exercise 2

Which of the following is the odd-one-out?

1) go beyond, exceed, overtop, reduce, overgrow

2) loosen, screw up, tighten, reinforce

3) loose, unattached, unfastened, narrow

4) recognize, forget, identify, recall

5) nondisposable, reusable, throwaway, recoverable

6) strengthen, impair, reduce, weaken

7) hose, fin, tube, duck, pipe

Exercise 3

Fill in the sentences with the words from the box

Recognized, impaired, duct, disposable, tightened (2), level (2), replace, variety, obstructing

1) His mouth __________into a thin line.

2) The cables are buried one metre below ground__________.

3) I __________her by her red hair.

4) The rope holding the boat suddenly________ and broke.

5) You can't park here, you're __________my driveway.

6) We ate off __________plates.

7) It is not a good idea to miss meals and them __________with snacks.

8) This tool can be used in a ________of ways

9) His age _________his chances of finding a new job.

10) The floodwater nearly reached roof_________.

11) They managed to get out of the building by crawling through a ventilation_________.

Exercise 4

Answer the questions

1) Why do some compressors have a relief valve?

2) How does a relief valve work?

3) Why are noises from the clutch difficult to recognize?

4) What can reduce the efficiency of an air conditioner?

5) What kinds of filters do you know?

6) How often should we clean or replace our air conditioning system’s filter?

Exercise 5

Guess the words described below.

1) a pipe or tube carrying liquid, gas, electric or telephone wires, etc.

2) made to be thrown away after use

3) to avoid (an obstacle) by using an alternative channel, passage, or route

4)  to think about something carefully, especially in order to make a decision

5) a position or rank in a scale of size or importance

6) to block a road, an entrance, a passage, etc. so that somebody/something cannot get through, see past, etc.