What is the psychometric properties of air?

Psychrometrics is the name given to the study of the air and water vapor mixture. Seven properties of atmospheric air are shown on the psychrometric chart. These properties are: dry bulb temperature, wet bulb temperature, dew point, humidity ratio, relative humidity, specific volume, and specific enthalpy.

What are the properties of moist air?

Moist Air Properties

• pressure of water vapor at saturation.
• humidity ratio at saturation.
• specific volume of dry air.
• specific volume of saturated mixture.
• specific enthalpy of dry air.
• specific enthalpy of saturated mixture.
• specific entropy of saturated mixture.

What are psychometric properties in refrigeration and air conditioning?

The psychrometric ratio is an important property in the area of psychrometry, as it relates the absolute humidity and saturation humidity to the difference between the dry bulb temperature and the adiabatic saturation temperature. Mixtures of air and water vapor are the most common systems encountered in psychrometry.

What are psychrometric properties?

Psychrometrics is the science of air and water vapor and deals with the properties of moist air. This chapter presents a psychrometric chart, which shows the properties of moist air in terms of dry-bulb temperature, wet-bulb temperature, relative humidity, humidity ratio, and enthalpy.

What is psychometric process?

Sensible Heating or Cooling> a psychrometric process that involves the increase or decrease in the temperature of air without changing its humidity ratio. Example: passing moist air over a room space heater and of kiln air over the heating coils.

When humidity is air what air is said to be dehumidified?

When humidity ratio of air ____ air is said to be dehumidified. Explanation: when it increases, air is said to be humidified. Explanation: These are the ways of cooling and dehumidifying air. 5.

What are the methods for determining the properties of moist air?

Properties of Moist Air:

• Dry-Bulb Temperature: Dry bulb temperature is what is usually meant by “air temperature”.
• Dew Point: Dew point is the temperature at which water vapor begins to condense out of the air.
• Wet-Bulb Temperature: Wet bulb temperature is relatively easy to measure, but requires special equipment.

What is the formula of moist air?

It has no chemical formula apart from the chemical formulae of its component parts. So H20 is the chemical formulae of the water component of moist air. O2 is the chemical formula of the oxygen component comprising moist air.

What are the 6 psychometric process?

This is the series of articles that describes psychrometric chart and various psychrometric processes like sensible heating, sensible cooling, humidification, de-dumidification, evaporative cooling etc.

What is a psychometric chart and what are its applications?

Psychrometric charts are complex graphs that can be used to assess the physical and thermodynamic properties of gas-vapour mixtures at a constant pressure. They are often used to assess the properties of moist air.

What is psychometry enlist various psychometric process?

The initial and final points on the psychrometric chart give all the properties of the air.  Sensible Heating of the Air Sensible heating process is opposite to sensible cooling process. In sensible heating process the temperature of air is increased without changing its moisture content.

What is the perfect conditions for dehumidification of air?

(D) Air is cooled below its dew point temperature.

How does relative humidity affect the psychrometric chart?

According to the psychrometric chart, if the relative humidity of the outside air is 80% and the outside air temperature is 85°F, when the air is cooled to 55°F, vapor will condense out of the air, and the relative humidity will be 100%.

What are the properties of air in a psychrometric chart?

The air properties on the chart are: Fig. 1.15. Psychrometric chart. (Reproduced from Section C1 of the CIBSE Guide, with the permission from the Chartered Institute of Building Services Engineers.) dry-bulb temperature, sling wet-bulb temperature, moisture content, specific enthalpy, specific volume, percentage saturation.

How does the properties of moist air change with altitude?

The exact properties of moist air vary with pressure. As pressure reduces as altitude increases the properties of moist air change with altitude. Typically, psychrometric charts are printed based on standard pressure at sea level. For the rest of this section we will consider pressure as constant.

What is the relative humidity of the air?

According to the psychrometric chart, if the relative humidity of the outside air is 80% and the outside air temperature is 85°F, when the air is cooled to 55°F, vapor will condense out of the air and the relative humidity will be 100%.