Comparison

HVAC RefCharge vs Psychrometric Chart

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

HVAC RefCharge

This app helps HVAC technicians quickly calculate refrigerant superheat and subcool levels. It supports over 100 refrigerants and offers interactive adjustments for precise charging decisions. Features include atmospheric pressure adjustments and unit customization.

Highlights
  • Superheat and subcool calculations
  • Supports 100+ refrigerants
  • Interactive slider for adjustments
  • Atmospheric pressure compensation
  • Customizable input types
  • Project photo assignment
  • Email report generation
  • English/Metric unit display
Features
Read full description

The HVAC RefCharge app is a refrigerant charging calculator that allows HVAC technicians to perform superheat and subcool refrigerant charge calculations on-the-fly. This app includes pressure/temperature data for over 100 refrigerants. This is a universal app that works on both the iPhone and iPad. This app now includes the HVAC Equipment Locator. Click here for details: http://bit.ly/1yTq539 The following is a list of additional features: 1. Perform superheat refrigerant charge calculations for 100+ different refrigerants. Input the indoor wet-bulb and outdoor dry-bulb temps. to get the target superheat temperature. Then, specify the suction line temperature and pressure to get the actual superheat temperature. The difference tells you whether to charge or not. Also, the app auto-assigns the dew version of azeotropic refrigerant to superheat, if applicable. 2. Perform subcool refrigerant charge calculations for 100+ different refrigerants. Input the indoor wet-bulb and outdoor dry-bulb temps. to get the target subcool temperature. Then, specify the liquid line temperature and pressure to get the actual subcool temperature. The difference tells you whether to charge or not. Also, the app auto-assigns the bubble version of azeotropic refrigerant to subcool, if applicable. 3. Use an interactive slider control to increase or decrease all values and immediately observe calculated results. Also, the slider control allows for "incremental" changes so you can ever-so-slightly change values to observe newly calculated results. 4. Specify atmospheric pressure (other than standard 14.7 psi) so that calculated pressures are adjusted for high elevations like those in Denver and elsewhere. 5. Customize input types so that you can specify manufacturer-specified target superheat/subcool or input indoor dry-bulb/indoor relative humidity in place of indoor wet-bulb temperature. 6. Take a photo and assign it to the project 7. Send an email that includes all inputs, results, and the photo with a custom message 8. Display input and result values in either English or Metric units

About

Psychrometric Chart

An interactive tool for HVAC engineers to create and manipulate psychrometric charts. Model various air processes, add and adjust state points with live property updates, and save multiple charts. Export your designs as PDFs or via AirPrint.

Highlights
  • Interactive psychrometric charts
  • Model air mixing and heating/cooling
  • Live state point adjustment
  • SI and IP unit support
  • Save and manage multiple charts
  • Export charts as PDF
  • AirPrint compatibility
Features
Read full description

Interactive, graphical psychrometric chart app for HVAC engineers and designers. Allows you to create and manipulate charts and state points with the touch of your finger(s). Processes that can be modeled include: • An individual state point. • Air mixing. • Sensible heating. • Sensible cooling. • Cooling coils. • Other processes by connecting state points. Add new state points by double tapping anywhere on the chart. Hold and drag existing state points to move them on the graph, with properties values updating live to aid you in setting them to the right value. Works in both SI and IP units. Allows you to create and save multiple charts. Properties and energy change for connected points are calculated and displayed live. Share your charts by exporting a PDF file or sending to an AirPrint device. Works on both the iPhone and iPad, but best used on the larger screen of the iPad. ------ We would very much like your feedback! Suggestions, complements, complaints, bug reports etc.: http://www.pheinex.com/contact/ If you like this app, please do not forget to rate it in the App Store! ----- Notes: This application (App) is provided for use by qualified HVAC engineers and designers in the design of air handling systems and is not a substitute for appropriate design services. When in doubt, contact a design

Screenshots

HVAC RefCharge4 screens
Psychrometric Chart2 screens

Verdict

The call

The clearest difference is price: HVAC RefCharge at $9.99 against Psychrometric Chart's $59.99. Psychrometric Chart's advantage is in-app purchases (none vs 1) and update cadence (every 3 months vs every 11 months). On review sentiment, ads, monetization model and device support 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

CostPrice · In-app purchases · Ads · Monetization

HVAC RefCharge costs $9.99 and Psychrometric Chart $59.99 up front. HVAC RefCharge sells 1 one-off in-app purchase. Psychrometric Chart asks for nothing beyond the download.

UpkeepUpdate frequency

HVAC RefCharge ships an update every 11 months, Psychrometric Chart every 3 months. The most recent releases landed on October 8, 2026 and October 7, 2026 respectively.

Scorecard3 real differences · 7 level
HVAC RefCharge versus Psychrometric Chart: the parameters behind the verdict, then further details
ParameterHVAC RefChargePsychrometric Chart
Price$9.99 — better$59.99
Rating—4.4 (34 ratings) — better
Positive reviews33.3% of reviews33.3% of reviews
Number of ratings—34 — better
Update frequencyEvery 11 monthsEvery 3 months — better
AdsNoNo
In-app purchasesYesNo — better
MonetizationPaidPaid
DevicesiPhone, iPad, iPodiPhone, iPad, iPod, Mac — better
Requires iOS15.615.0 — better
Further details — not scored
Size22 MB32 MB
Age rating4+4+
DeveloperCarmel Software CorporationPheinex, LLC

Customer experience

HVAC RefCharge

Written reviews3 reviews
Positive33.3%
Neutral33.3%
Negative33.3%

Psychrometric Chart

All ratings34 ratings
Positive82.4%
Neutral5.9%
Negative11.8%
Written reviews6 reviews
Positive33.3%
Neutral16.7%
Negative50.0%

In-app purchases

1 purchases

HVAC RefCharge

One-time1
  • HVAC Equipment Locator$9.99
None

Psychrometric Chart

No in-app purchases

Questions

Is HVAC RefCharge free?
HVAC RefCharge costs $9.99, and also offers in-app purchases.
Is Psychrometric Chart free?
Psychrometric Chart costs $59.99, with no in-app purchases.
Do HVAC RefCharge or Psychrometric Chart have ads?
Neither HVAC RefCharge nor Psychrometric Chart shows ads.
Which is updated more often, HVAC RefCharge or Psychrometric Chart?
HVAC RefCharge ships an update every 11 months, and Psychrometric Chart every 3 months. Most recently, HVAC RefCharge was updated on October 8, 2026 and Psychrometric Chart on October 7, 2026.

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