Comparison

HVAC Toolkit Ultimate vs Study Guide Pro

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

Head to head
About

HVAC Toolkit Ultimate

This comprehensive application offers a suite of tools for HVAC professionals, including load calculations, equipment tracking, refrigerant charts, duct and pipe sizing, and psychrometric analysis. It consolidates multiple functionalities into a single, powerful utility for field and office use.

Highlights
  • Residential load calculations
  • Equipment nameplate data tracking
  • Refrigerant pressure-temperature charts
  • Superheat and subcool calculations
  • Duct and pipe sizing analysis
  • Psychrometric calculations
  • Steam table property calculations
Features
Read full description

This may just be the only HVAC app you will ever need. The HVAC Toolkit Ultimate from Carmel Software is a universal app that works on both the iPhone and iPad. It is the essential app for anyone in the HVAC industry. It is a compilation of most of the individual iPhone and iPad applications offered by Carmel Software plus bonus software. If you bought each of these apps separately, it would cost more than 2 times what the price of this app is. It includes: 1. HVAC Residential Load Calc HD (iPad version) 1. HVAC Residential Load Calcs (iPhone version) 1. HVAC Equipment Locator 2. HVAC PT Chart 3. HVAC Refrigerant Charge 4. HVAC Duct Sizer 2. HVAC Quick Load 6. ASHRAE Ventilation Calcs (iPhone version) 7. Psychrometrics 8. Steam Tables 9. HVAC Pipe Sizer - Liquid 10. HVAC Pipe Sizer - Steam 11. HVAC Pipe Sizer - Gas Low 12. HVAC Pipe Sizer - Gas High The "HVAC Residential Load Calcs" module allows you to perform comprehensive HVAC block and room-by-room load calculations for small commercial and residential buildings. You can easily use this module out in the field by taking advantage of the simplicity and power of the iPhone or iPad, and then email results back to your office. The "HVAC Equipment Locator" module allows you to track, share, and customize your equipment nameplate and maintenance data. The version here includes the ability to customize your input screens (this is usually an in-app purchase on the free stand-alone version of Locator, but it is included here). The "HVAC PT Chart" module allows you to easily view the pressure-temperature properties of 100 refrigerants. Think of this app as a digital version of the paper PT charts that you may have carried around with you in the past. The "HVAC Refrigerant Charge" module allows you to perform superheat and subcool refrigerant charge calculations on-the-fly. This app includes pressure-temperature data for over 100 common refrigerants including azeotropic (bubble/dew) versions of refrigerants. The "HVAC Duct Sizer" module allows you to perform quick and simple duct sizing analysis. You can specify the total airflow in CFM (or L/s), the aspect ratio and one of either the velocity of air or the friction loss per 100 feet (30 meters). The results include both the exact and rounded height and width (or diameter) dimensions and the calculated velocity and friction loss. In addition, you can calculate for a range of duct sizes by specifying minimum and maximum friction loss and airflow values. The "HVAC Quick Load" module allows you to quickly calculate total heating and cooling loads for a wide variety of building types. The "Psychrometrics" module allows you to easily perform single-state and mixed-air HVAC psychrometric calculations for up to 23 different combinations of input parameters. The "Steam Tables" module allows you to calculate the properties of saturated or superheated steam by specifying 2 input properties. This module is also part of the "Pipe Sizer - Steam" module discussed below. The "ASHRAE Ventilation Calcs" module allows you to perform comprehensive minimum ventilation calculations for a wide variety of commercial buildings based upon ASHRAE Standard 62.11-2007 and 2010/2013 versions. The "HVAC Pipe Sizer - Liquid" module allows you to size a pipe run for many different types of liquids (or fluids), pipe material and fitting types. The "HVAC Pipe Sizer - Steam" module allows you to size a steam pipe run, and it also includes a bonus steam table calculator. The "HVAC Pipe Sizer - Gas Low and Gas High" modules allows you to quickly size a simple low (less than or equal to 1.5 psi) and high (greater than 1.5 psi) pressure gas piping system by inputting a number of piping and gas properties. All values can be displayed in English (IP) and Metric (SI) units. We also offer all of the above modules as individual apps, too.

About

Study Guide Pro

Create and review custom study guides for any subject. Organize questions and answers, randomize them for practice, and access your guides on your Apple Watch. Perfect for preparing for quizzes, tests, and certifications.

Highlights
  • Create custom study guides
  • Add questions and answers
  • Randomize question order
  • Create multiple guides
  • Edit existing entries
  • Apple Watch integration
Features
Read full description

Study Guide Pro helps you study for anything. From quizzes, tests, exams, certifications, etc. You just need to: * Give your study guide a name * Enter your questions and answers My Study Guide Po will help you review everything you entered into it. Study Guide Pro allows you to: * Randomize your question/answers * Create multiple study guides * Edit questions/answers as many times as you need to * Browse your study guides easily on your Apple Watch Please contact us using the support link below for any errors/bugs/feature requests.

Screenshots

HVAC Toolkit Ultimate4 screens
Study Guide Pro4 screens

Verdict

The call

The clearest difference is price: Study Guide Pro at $2.99 against HVAC Toolkit Ultimate's $59.99. Study Guide Pro also leads on rating (4.0 vs 3.0) and update cadence (every 2 months vs every 6 months). HVAC Toolkit Ultimate's advantage is review sentiment (40% vs 0%) and iOS requirement (13.0 vs 15.6). On ratings volume, ads, in-app purchases 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

CostPrice · In-app purchases · Ads · Monetization

HVAC Toolkit Ultimate costs $59.99 and Study Guide Pro $2.99 up front. Neither carries in-app purchases, so what you see is what you pay.

ReceptionRating · Positive reviews · Number of ratings

Study Guide Pro holds the better App Store score, 4.0 against 3.0. Both are backed by a comparable volume of ratings — 4 and 2 respectively. Written reviews complicate that: 40% of HVAC Toolkit Ultimate's written reviews are positive against 0% of Study Guide Pro's, so the app with the better star average is not the one people write more warmly about.

UpkeepUpdate frequency

HVAC Toolkit Ultimate ships an update every 6 months, Study Guide Pro every 2 months. The most recent releases landed on September 26, 2026 and September 10, 2026 respectively.

Scorecard5 real differences · 5 level
HVAC Toolkit Ultimate versus Study Guide Pro: the parameters behind the verdict, then further details
ParameterHVAC Toolkit UltimateStudy Guide Pro
Price$59.99$2.99 — better
Rating3.0 (4 ratings)4.0 (2 ratings) — better
Positive reviews40.0% of reviews — better0.0% of reviews
Number of ratings4 — better2
Update frequencyEvery 6 monthsEvery 2 months — better
AdsNoNo
In-app purchasesNoNo
MonetizationPaidPaid
DevicesiPhone, iPad, iPodiPhone, iPad, iPod, Apple Watch — better
Requires iOS13.0 — better15.6
Further details — not scored
Size59 MB2 MB
Age rating4+4+
DeveloperCarmel Software CorporationPablo Arista

Customer experience

HVAC Toolkit Ultimate

All ratings4 ratings
Positive50.0%
Neutral0.0%
Negative50.0%
Written reviews15 reviews
Positive40.0%
Neutral6.7%
Negative53.3%

Study Guide Pro

All ratings2 ratings
Positive50.0%
Neutral50.0%
Negative0.0%
Written reviews1 reviews
Positive0.0%
Neutral100.0%
Negative0.0%

In-app purchases

None

HVAC Toolkit Ultimate

No in-app purchases

None

Study Guide Pro

No in-app purchases

Questions

Is HVAC Toolkit Ultimate free?
HVAC Toolkit Ultimate costs $59.99, with no in-app purchases.
Is Study Guide Pro free?
Study Guide Pro costs $2.99, with no in-app purchases.
Which has better reviews, HVAC Toolkit Ultimate or Study Guide Pro?
Study Guide Pro is rated higher. HVAC Toolkit Ultimate averages 3.0 out of 5 from 4 ratings, while Study Guide Pro averages 4.0 from 2 ratings.
Do HVAC Toolkit Ultimate or Study Guide Pro have ads?
Neither HVAC Toolkit Ultimate nor Study Guide Pro shows ads.
Which is updated more often, HVAC Toolkit Ultimate or Study Guide Pro?
HVAC Toolkit Ultimate ships an update every 6 months, and Study Guide Pro every 2 months. Most recently, HVAC Toolkit Ultimate was updated on September 26, 2026 and Study Guide Pro on September 10, 2026.

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