HVAC PT Chart is an electronic pressure temperature calculator that allows HVAC technicians and contractors to quickly look up the temperature and corresponding pressure for 100+ common HVAC refrigerants including both bubble and dew versions of azeotropic (mixture) refrigerants. This is the only PT Chart app that allows you to email complete PT chart lists, refrigerant properties, and your inputted values/results.

This is a unique PT Chart app for the following reasons:

1. Works on both the Apple iPhone and iPad (and adjusts its screen according to the mobile device screen size, whether you are running it on the iPhone 6 or the iPad)

2. Optimized for iOS 13

3. Includes 100+ refrigerants

4. Allows you to input the temperature and then the corresponding pressure will display and vice versa.

5. Allows you to also use a slider control to specify the exact pressure or temperature to see the corresponding temperature or pressure

6. Displays a list of pressure/temperature values in 1 degree increments

7. Allows you to select the atmospheric pressure so as to show the true pressure-temperature relationship even for high elevations

8. Includes a database of 1000+ cities world-wide with elevation data that is used to derive atmospheric pressure

9. Display common properties for the selected refrigerant (oil type, GWP, composition, critical temp, boiling temp, and more...)

10. Email project inputs and properties for the selected refrigerant

11. Email the full pressure/temperature list for the selected refrigerant

12. Display units in both English and Metric

13. Includes both dew and bubble versions of any azeotropic (mixture) refrigerants

14. This app now includes the HVAC Equipment Locator. Click here for details:

What’s New

Version 4.5

1. Fixed the "negative sign" issue that occurs in iOS 13
2. Fixed issue with not displaying properly in iOS 13 "dark mode"

Ratings and Reviews

3.9 out of 5
7 Ratings

7 Ratings

TheFlyingTurkey ,

Pretty good but needs tweaking

This PT chart app is probably the best on iTunes because it has every refrigerant on the planet, but the interface could be better. On my iPhone the refrigerant selection window takes up half the screen. That leaves a lot less space to view the temps and pressures I need. You guys need to shrink down the refrigerant selection window so it is easier to use the buttons and slider. Also it would free up space to make the readout windows a little bigger so it's easier to see the numbers.

Other than that the app works great and is pretty accurate. The info is good, it just needs a better presentation.

HVAC life ,

Practical and useful

Exactly what I needed. Free app but wouldn't have minded paying for it. Gets the job done. Simple to use. Great all around app

Mechengineer1000 ,

Love this app and it’s free!

This app has all the refrigerants that I need in the field and it’s so easy to use. It now works ok in dark mode too.


Carmel Software Corporation
30.3 MB

Requires iOS 9.0 or later. Compatible with iPhone, iPad, and iPod touch.



Age Rating
In-App Purchases
  1. HVAC Equipment Locator $9.99


  • Family Sharing

    With Family Sharing set up, up to six family members can use this app.

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