HVAC PT Chart vs SmarTech
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
HVAC PT Chart
This tool provides HVAC technicians with instant access to pressure and temperature data for over 100 refrigerants. It allows users to input one value to find the other, view detailed refrigerant properties, and email comprehensive charts and data.
- Pressure/temperature lookup for 100+ refrigerants
- Input temperature to find pressure, or vice versa
- Slider control for precise value selection
- Email complete PT chart lists and refrigerant properties
- Display common refrigerant properties
- Adjust for atmospheric pressure based on city elevation
- English and Metric unit options
Read full descriptionHide full description
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 13 or the iPad) 2. Optimized for iOS 16 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: http://bit.ly/1yTq539
SmarTech
This app connects to a digital manifold to display accurate pressure and temperature readings. It offers real-time Superheat and Subcooling calculations, supports over 109 refrigerants, and features a "Smart Charge Zone" for optimal system charging. Users can also generate and export system performance reports.
- Real-time pressure and temperature readings
- Superheat and Subcooling calculations
- 109+ refrigerant types supported
- Smart Charge Zone indicator
- System performance reporting
- PDF/CSV report export
Read full descriptionHide full description
The Uniweld SmarTech™ Digital Manifold App communicates with your SmarTech™ Digital Manifold to clearly display professionally accurate pressure and temperature readings in the palm of your hand. Monitor target and actual Superheat and Subcooling calculations in real-time, as pressure and temperature readings fluctuate. Choose from over 109 different refrigerant types and create a custom list of your most commonly used refrigerants. SMART CHARGE ZONE: All the guess work is taken out of properly charging the system with the color coded Smart Charge Zone feature. The difference between the target and actual Superheat or Subcooling is shown with color indicators that signal whether the system is overcharged (RED), undercharged (BLUE), or has an accurate "In The Zone" system charge (GREEN). REPORTING: Take your business to the next level with system performance reporting. Enter company details along with customer and equipment information and with one touch, produce a SmarTech™ Verified System Performance Report that is ready for export as a PDF or CSV file. Reports can easily be emailed for saving, tracking, or printing. Uniweld Products, Inc... "Quality Tools That Go To Work With You®". This app also works as a free, stand-alone P/T Calculator!
Screenshots
Verdict
The clearest difference is in-app purchases: SmarTech at none against HVAC PT Chart's 1. HVAC PT Chart's advantage is rating (4.0 vs 3.6) and review sentiment (56% vs 25%). On price, ratings volume, ads and monetization model there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Both are free to download. HVAC PT Chart sells 1 one-off in-app purchase. SmarTech asks for nothing beyond the download.
HVAC PT Chart holds the better App Store score, 4.0 against 3.6. Both are backed by a comparable volume of ratings — 8 and 9 respectively. Written reviews point the same way: 56% of HVAC PT Chart's written reviews are positive against 25% of SmarTech's.
HVAC PT Chart ships an update every 4 months, SmarTech every 12 months. The most recent releases landed on September 9, 2026 and June 1, 2026 respectively.
| Parameter | HVAC PT Chart | SmarTech |
|---|---|---|
| Price | Free | Free |
| Rating | 4.0 (8 ratings) — better | 3.6 (9 ratings) |
| Positive reviews | 55.6% of reviews — better | 25.0% of reviews |
| Number of ratings | 8 | 9 — better |
| Update frequency | Every 4 months — better | Every 12 months |
| Ads | No | No |
| In-app purchases | Yes | No — better |
| Monetization | Free | Free |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Requires iOS | 13.1 — better | 15.6 |
| Further details — not scored | ||
| Size | 27 MB | 21 MB |
| Age rating | 4+ | 4+ |
| Developer | Carmel Software Corporation | Uniweld Products, Inc. |
Customer experience
HVAC PT Chart
SmarTech
In-app purchases
HVAC PT Chart
- HVAC Equipment Locator$9.99
SmarTech
No in-app purchases








