Psychrometry used in Hvac

 Psychrometry

Psychrometry is defined as the science dealing with the physical laws of air - water 💦vapour mixtures 

Psychrometry chart 📊contains relations between properties of air and moisture

Pschrometry properties

Dry bulb temperature🌡️DBT

Wet 💦bulb temperature🌡️WBT

Relative humidity RH

Humidity Ratio HR or specific Humidity W

Dew point📍 temperature🌡️DPT

Dry bulb temperature🌡️DBT it is the  temperature🌡️of air measured by thermometer

Wet 💦bulb temperature WBT it is the temperature🌡️of air measured by thermometer🌡️ whose bulb is covered with a wet 💦wick or cloth 

Relative humidity RH is also defined as the amount of water 💦vapour present in the air to the maximum amount of water 💦vapour that air can hold

RH has no unit 

It is represented by% percentage

Humidity Ratio HR or specific humidity w

It is defined as the number of water 💦grains present in one pound of air is known as specific humidity w or Humidity Ratio HR

Dew point📍 Temperature 🌡️DPT

 it is defined as the temperature🌡️at which water 💦vapour condense to liquid is known as Dew point📍 tempreture

Psychrometric process are very important parameters for hvac 

The four parameters are given below

Cooling

Decreasing the temperature🌡️ by removing heat 

Heating 

Increasing the temperature🌡️ by adding heat

Humdification

Increasing the humidity levels

Dehumidification

Decreasing the humidity levels