A psychrometric chart presents
physical and thermal properties of moist air in a graphical form
. It can be very helpful in troubleshooting and finding solutions to greenhouse or livestock building environmental problems.
What values are plotted on a psychrometric chart?
Using the Psychrometric Chart neatly plot the required air conditioning process and estimate (a)
the amount of moisture removed
[11.5g-H20/kg-dry-air], (b) the heat removed [(1)-(2), q
cool
= 48kJ/kg-dry-air], and (c) the amount of heat added [(2)-(3), q
heat
= 10kJ/kg-dry-air].
What is the importance of psychrometric chart?
The psychrometric chart is an industry-standard tool that
is used to visualize the interrelationships between dry air, moisture, and energy
. If you are responsible for the design or maintenance of any aspect of air-conditioning in buildings, a clear and comfortable understanding of the chart will make your job easier.
What substance properties can be displayed by psychrometric chart?
A psychrometric chart shows the
inter-relationship between dry bulb temperature, wet bulb temperature and the humidity ratio
. It also shows the relative humidity, the dew point temperature and sometimes the enthalpy of the mixture and the specific volume.
Is psychrometric chart accurate?
While this method is
not accurate enough
for laboratory calculations, it is useful for field calculations using the psychrometric chart, where extreme accuracy is not of prime importance. On most psychrometric charts space is limited so that only the total heat content of the air is shown.
What are the important psychrometric process?
Some of the common psychrometric processes carried out on air are:
sensible heating and cooling of air, humidification and dehumidification of air
, mixing of various streams of air, or there may be combinations of the various processes.
What is called WBT?
The
wet-bulb temperature
(WBT) is the temperature read by a thermometer covered in water-soaked cloth (wet-bulb thermometer) over which air is passed. … The wet-bulb temperature is the lowest temperature that can be reached under current ambient conditions by the evaporation of water only.
How do you analyze a psychrometric chart?
Take a ruler and draw a vertical line at the dry bulb temperature of 70 and draw a horizontal line where
the dew point is 50. The point where these two lines intersect is known as a ‘state point’. Plot the state point and you can also read the rel- ative humidity, wet bulb, enthalpy, vapor pressure and humidity ratio.
What are the psychrometric properties?
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 is WBT and DBT?
Dry bulb temperature (DBT or td): The temperature of moist air as measured by ordinary thermometer when placed in air is called dry bulb temperature.
Wet bulb temperature
(WBT or tw): … When air is passed over the wet wick, moisture contained in the wick evaporates and cooling effect is produced at the bulb.
What is psychrometric ratio?
The psychrometric ratio is
the ratio of the heat transfer coefficient to the product of mass transfer coefficient and humid heat at a wetted surface
.
How do you calculate grain depression?
French translation: diminution de la proportion de grains de vapeur d’eau. Gain depression is calculated by
taking temperature and R/H of the air
going into your dehumidifier and the processed Air coming out with the thermo hygrometer. Calculate the GPP and subtract the out going grains from the in coming grains.
What is saturated air?
When a volume of air at a given temperature holds the maximum amount of water vapour
, the air is said to be saturated. … Saturated air, for example, has a relative humidity of 100 percent, and near the Earth the relative humidity very rarely falls below 30 percent.
What is psychrometric chart what is it used for how is it used?
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.
