If 5.0 cubic meters per second of air enters a heating coil at 20°C dry bulb and 15°C wet bulb, and leaves the heating coil at 30°C dry bulb, what is the change in enthalpy?
a. 52 kJ/kg
b. 42 kJ/kg
c. 15 kJ/kg
d. 20 kJ/kg
e. 11 kJ/kg
Answer: E
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Power Engineering Chapter 126
- The comfort of human beings is affected by the atmospheric conditions surrounding them. Which of the following is not an atmospheric condition which affects comfort?
- During sensible heating the dry-bulb temperature and the wet-bulb temperature are raised, and
- Using the psychrometric chart, find the relative humidity if the dry-bulb temperature is 25 degrees C and the wet-bulb temperature is 25 degrees C.
- Which of the following statements about cooling and dehumidification is false?
- The intersection between the line running vertically from the point on the dry-bulb scale and the downward diagonally running line from the wet-bulb scale is defined as
- Which of the following properties cannot be found on the psychrometric chart?
- Using the psychrometric chart, find the enthalpy if the dry bulb temperature is 20°C and the wet bulb temperature is 15°C.
- An increase in air flow increases heat loss of the body by which of the following methods:
- During the winter, the majority of people feel comfortable when the effective temperature is approximately between:
- During sensible heating, only the _________________ decreases.
- Using the psychrometric chart, find the relative humidity if the dry bulb temperature is 20°C and the wet bulb temperature is 15°C.
- Evaporative cooling results in:
- Using the psychrometric chart, find the enthalpy if the dry bulb temperature is 25°C and the wet bulb temperature is 20°C.
- During the summer, the majority of people feel comfortable when the effective temperature is approximately between:
- Using the psychrometric chart, find the dew point temperature at a dry bulb temperature of 20°C and a wet bulb temperature of 15°C.
- If 5.0 cubic meters per second of air enters a heating coil at 20°C dry bulb and 15°C wet bulb, and leaves the heating coil at 30°C dry bulb, what is the approximate volume of air leaving the coil?
- Air used for ventilating purposes in an office building should be kept within a certain range of relative humidity as indicated below:
- Using the psychrometric chart, find the specific volume if the dry bulb temperature is 20°C and the wet bulb temperature is 15°C.
- People need considerable time to adjust when moving from one space to another, when temperature and humidity conditions vary widely. This may be described as?
- Effective temperature is defined as a measure of comfort that involves:
- Using the psychrometric chart, find the enthalpy if the dry bulb temperature is 20°C and the wet bulb temperature is 15°C.
- A measure of comfort that involves the combined effects of the dry bulb temperature, relative humidity and air movement is defined as: