Psychrometrics Flashcards
(24 cards)
What is psychrometrics?
The study of the properties of moist air and its behavior.
True or False: Humidity is a measure of the amount of moisture in the air.
True
What is the difference between relative humidity and absolute humidity?
Relative humidity is the ratio of current moisture in the air to the maximum moisture the air can hold at a given temperature, while absolute humidity is the actual amount of moisture in a given volume of air.
Fill in the blank: The _______ is a graphical representation of the thermodynamic properties of moist air.
psychrometric chart
What does the wet bulb temperature indicate?
The wet bulb temperature indicates the lowest temperature that can be achieved by evaporative cooling.
Multiple Choice: Which of the following is not a property shown on a psychrometric chart? A) Dry bulb temperature B) Relative humidity C) Wind speed D) Dew point temperature
C) Wind speed
What is dew point temperature?
The temperature at which air becomes saturated with moisture and water vapor begins to condense.
True or False: Specific enthalpy is the total heat content per unit mass of air.
True
What is the formula to calculate the specific humidity?
Specific humidity = (mass of water vapor) / (mass of dry air + mass of water vapor)
Fill in the blank: A higher _______ indicates more moisture in the air.
specific humidity
Multiple Choice: What is the primary purpose of air conditioning systems? A) To increase humidity B) To decrease temperature C) To control temperature and humidity D) To filter air
C) To control temperature and humidity
What is the significance of the psychrometric process in HVAC?
It helps in understanding and controlling the thermal comfort and air quality in indoor environments.
True or False: The enthalpy of moist air increases with an increase in moisture content.
True
What happens to the relative humidity when the temperature of air increases while the moisture content remains the same?
Relative humidity decreases.
Fill in the blank: The _______ process involves cooling air without changing its moisture content.
sensible cooling
What is the primary component of the psychrometric chart?
Dry bulb temperature
Multiple Choice: Which component is used to measure humidity? A) Psychrometer B) Barometer C) Anemometer D) Thermometer
A) Psychrometer
What is latent heat?
The heat absorbed or released by a substance during a phase change without changing its temperature.
True or False: The process of humidifying air is considered a latent heat process.
True
What is the effect of increased ventilation on indoor air quality?
Increased ventilation generally improves indoor air quality by diluting indoor pollutants.
Fill in the blank: The _______ is the temperature at which air reaches 100% relative humidity.
dew point temperature
What is the relationship between dry bulb temperature and wet bulb temperature?
The wet bulb temperature is always less than or equal to the dry bulb temperature.
Multiple Choice: Which factor does NOT affect the performance of HVAC systems? A) Outdoor temperature B) Building orientation C) Indoor plants D) Humidity levels
C) Indoor plants
What is the purpose of dehumidification in HVAC?
To reduce the moisture content in the air to improve comfort and prevent mold growth.
