EQS Air – Psychrometric Chart
Moist air states & HVAC loads
$19.99
Slide a point across the psychrometric chart and watch its mixtures and coil loads follow. One purchase for iPhone, iPad and Mac.
EQS Air puts a working psychrometric chart on your iPhone, your iPad and your Mac. One purchase covers all three.
THE CHART IS THE CALCULATOR
Each air state you enter becomes a point on the chart, among lines of saturation, relative humidity, enthalpy and specific volume. Slide a point with your finger or the mouse: its properties change as it moves, and so does every mixture and process that uses it. Tap an open part of the chart to read the air there, then keep it as a new point.
START FROM YOUR READINGS
A sling psychrometer, a hygrometer's dew point, a value from a datasheet: choose the pair you have from eleven combinations and type the two numbers. EQS Air shows all eight properties together: dry and wet bulb temperature, dew point, relative humidity, enthalpy, humidity ratio, density and specific volume.
MIX STREAMS, SIZE COILS
Blend outdoor and return air by their airflows and see where the mixed air lands. If the blend would pass the saturation curve, EQS Air warns you and gives the water that condenses as fog. Join two points as a cooling coil, a heater or a humidifier, enter the airflow, and get the total, sensible and latent load, the sensible heat ratio and the water removed or added.
AT YOUR SITE'S ALTITUDE
Enter the elevation once. The barometric pressure follows the standard atmosphere, and the chart and all the results are computed for it.
SI OR US UNITS
°C, kPa, kJ/kg, g/kg and m³/h, or °F, psia, Btu/lb, grains per pound, CFM and tons of refrigeration. One tap changes the whole app.
CHECKED AGAINST A REFERENCE
The moist-air equations of the ASHRAE Handbook — Fundamentals, with Hyland and Wexler's saturation pressure over water and over ice. The results are tested against CoolProp, the open-source property library used in research and industry.
PRIVATE BY DESIGN
No sign-up, no ads, no analytics and no internet connection needed. Copy any result as a table into a spreadsheet, a report or an e-mail.
From the developer of EQS, the engineering equation solver.
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The developer, stefan butucea, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Collected
The developer does not collect any data from this app.
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- stefan butucea
- Size
- 5.1 MB
- Category
- Utilities
- Compatibility
Requires iOS 16.0 or later.
- iPhone
Requires iOS 16.0 or later. - iPad
Requires iPadOS 16.0 or later. - Mac
Requires macOS 12.0 or later. - Apple Vision
Requires visionOS 1.0 or later.
- iPhone
- Languages
- English
- Age Rating
4+
- 4+
- Copyright
- © 2026 Stefan Butucea
