A psychrometric chart is a visual tool that shows the thermal properties of air at a constant pressure. HVAC professionals use it to analyze relationships between temperature, humidity, enthalpy, and other air characteristics. It helps design and optimize systems for comfort, efficiency, and indoor air quality.
/ˌsaɪkroʊˈmɛtrɪk ʧɑːrt/
A psychrometric chart is a visual tool that shows the thermal properties of air at a constant pressure. HVAC professionals use it to analyze relationships between temperature, humidity, enthalpy, and other air characteristics. It helps design and optimize systems for comfort, efficiency, and indoor air quality.
Why is a psychrometric chart useful?
It shows how air temperature and humidity interact, helping optimize HVAC design and comfort.
Source: The Cooling Company
Dry-bulb, humidity, and enthalpy relationships at a glance.
An HVAC engineer uses the chart to size equipment that meets target indoor temperature and humidity based on outdoor conditions.
Learning the key lines—dry-bulb, wet-bulb, and relative humidity—helps you read system performance quickly.
“Learning the key lines—dry-bulb, wet-bulb, and relative humidity—helps you read system performance quickly.”
Psychrometric comes from Greek words meaning “cold” and “measure.”
Do I need a psychrometric chart for normal maintenance?
Not always, but it’s valuable for diagnosing humidity and comfort issues.
What is the most important line on the chart?
Dry-bulb temperature and relative humidity lines are the most commonly used.
Are there digital psychrometric charts?
Yes. Many HVAC apps provide interactive charts for field use.
Fill out the form and we'll get back to you within 24 hours.
