超星 - 第18周的课堂练习 - 查题吧

单选题

( )may be defined as the process of adding heat to an enclosed space to maintain itstemperature above ambient.

A. Heating
B. Ventilation
C. Dehumidify
D. Refrigeration

单选题

On board ships, temperature maintenance can be made easier by increasing the ratio ofrecirculated to fresh air. Most air conditioning units have( )for adjusting this ratio.

A. catch plates
B. dampers
C. regulating valves
D. fans

单选题

The cooling coil also performs the dehumidification function. If the coil temperature is below the air( ), water vapor will condense and air humidity will be lowered.

A. triple point
B. boiling point
C. solidifying point
D. dew point

单选题

In order to maintain the desired( )in the conditioned spaces, the HVAC system must addor remove thermal energy to or from the space.

A. temperature
B. humidity
C. temperature or humidity
D. temperature and humidity

单选题

The purpose of the( ). in the vapor compression cycle is to accept the low-pressure dry afrom the evaporator and raise its pressure to that of the condenser.

A. condenser
B. compressor
C. evaporator
D. expansion valve

单选题

The purpose of the expansion valve is to control the flow of refrigerant from the high-pressescondensing side of the system into the low-pressure( )

A. condenser
B. expansion valve
C. evaporator
D. compressor

单选题

When cooling is by direct expansion, a separate( )is fitted in the unit for winter heating.

A. central heater
B. electrical heater
C. hot water coil
D. steam heater coil

单选题

If air at 95 'C dry bulb temperature and 50% relative humidity is conditioned to 75 C dry bulbtemperature and 50% relative humidity, it is an example of( )

A. cooling only
B. cooling and humidifying
C. cooling and dehumidifying
D. adiabatic cooling

单选题

Which of the following functions is NOT one of the functions of air conditioner?( )

A. Refreshing the air.
B. Waking up.
C. Adjusting the air humidity.
D. Adjusting the air temperature.

单选题

A wise precaution for an engineer to take is to go through accommodation and public roomsperiodically recording( )

A. dry bulb temperature
B. wet bulb temperature
C. wet and dry bulb temperatures
D. air humidity

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