Comparison

HVAC Toolkit Ultimate vs HydroCalc Plus

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

HydroCalc Plus

A professional tool for hydraulic engineers to calculate pressure losses in piping systems. It supports US and SI units, offers an extensive pipe material and fittings database, and includes inverse calculations for design optimization.

Highlights
  • Friction head loss calculation (Hazen-Williams)
  • US and SI unit support
  • Extensive pipe material library
  • Fittings and valves database
  • Inverse calculation mode
  • Real-time results (velocity, losses)
Features
Read full description

Professional hydraulic engineering tool for calculating pressure losses in piping systems. Essential for engineers, plumbers, and contractors designing water distribution networks. Key Features: Calculate friction head losses using industry-standard Hazen-Williams equation Support for both US (ft, gpm, psi) and SI (m, lps, bar) units Extensive pipe material library with pre-defined roughness coefficients (C-factors) Complete fittings and valves database including elbows, tees, valves, contractions, and expansions Inverse calculations to determine optimal pipe diameter, flow rate, or length for target head loss Real-time results showing velocity, friction loss, minor losses, and total system head loss What Sets Pro Apart: Unlike basic calculators, HydroCalc Pro accounts for both major losses (pipe friction) and minor losses (fittings and valves). The app includes a comprehensive database of K-factors for various components, allowing accurate total system pressure loss calculations. Perfect For: Water supply system design Irrigation network planning HVAC piping calculations Fire protection systems Industrial fluid transport Educational purposes in hydraulic engineering Technical Capabilities: The app considers all critical factors affecting pressure loss: flow velocity, pipe diameter, internal roughness, pipe length, and fitting configurations. Materials include PVC, polyethylene, steel, cast iron, concrete, and more with accurate C-factors ranging from 120-150. Inverse Calculation Mode: Unique feature allowing backward calculations - determine required pipe size for allowable head loss, maximum flow capacity, or optimal pipe length for your system constraints. Simple, intuitive interface with instant results. No internet connection required. Professional-grade calculations in your pocket. Note: Premium modules are available in English and Spanish.

Screenshots

HVAC Toolkit Ultimate4 screens
HydroCalc Plus4 screens

Verdict

The call

The clearest difference is review sentiment: HydroCalc Plus at 100% against HVAC Toolkit Ultimate's 40%. HydroCalc Plus also leads on price ($3.99 vs $59.99) and rating (5.0 vs 3.0). HVAC Toolkit Ultimate's advantage is in-app purchases (none vs 4) and ratings volume (4 vs 1). On 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 Toolkit Ultimate costs $59.99 and HydroCalc Plus $3.99 up front. HydroCalc Plus sells 4 one-off in-app purchases. HVAC Toolkit Ultimate asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

HydroCalc Plus holds the better App Store score, 5.0 against 3.0. Both are backed by a comparable volume of ratings — 4 and 1 respectively. Written reviews point the same way: 40% of HVAC Toolkit Ultimate's written reviews are positive against 100% of HydroCalc Plus's.

UpkeepUpdate frequency

HVAC Toolkit Ultimate ships an update every 6 months, HydroCalc Plus every 3 weeks. The most recent releases landed on August 27, 2026 and August 31, 2026 respectively.

Scorecard7 real differences · 3 level
HVAC Toolkit Ultimate versus HydroCalc Plus: the parameters behind the verdict, then further details
ParameterHVAC Toolkit UltimateHydroCalc Plus
Price$59.99$3.99 — better
Rating3.0 (4 ratings)5.0 (1 ratings) — better
Positive reviews40.0% of reviews100.0% of reviews — better
Number of ratings4 — better1
Update frequencyEvery 6 monthsEvery 3 weeks — better
AdsNoNo
In-app purchasesNo — betterYes
MonetizationPaidPaid
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS13.0 — better15.1
Further details — not scored
Size59 MB34 MB
Age rating4+4+
DeveloperCarmel Software CorporationTransparent Blue Water LLC

Customer experience

HVAC Toolkit Ultimate

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

HydroCalc Plus

All ratings1 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews1 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

In-app purchases

None

HVAC Toolkit Ultimate

No in-app purchases

4 purchases

HydroCalc Plus

One-time4
  • Pump Power Calculator$1.99
  • System Curve Generator$1.99
  • Pipe Database$1.99
Show 1 more
  • Industrial Fluids Pack$2.99

Questions

Is HVAC Toolkit Ultimate free?
HVAC Toolkit Ultimate costs $59.99, with no in-app purchases.
Is HydroCalc Plus free?
HydroCalc Plus costs $3.99, and also offers in-app purchases.
Which has better reviews, HVAC Toolkit Ultimate or HydroCalc Plus?
HydroCalc Plus is rated higher. HVAC Toolkit Ultimate averages 3.0 out of 5 from 4 ratings, while HydroCalc Plus averages 5.0 from 1 ratings.
Do HVAC Toolkit Ultimate or HydroCalc Plus have ads?
Neither HVAC Toolkit Ultimate nor HydroCalc Plus shows ads.
Which is updated more often, HVAC Toolkit Ultimate or HydroCalc Plus?
HVAC Toolkit Ultimate ships an update every 6 months, and HydroCalc Plus every 3 weeks. Most recently, HVAC Toolkit Ultimate was updated on August 27, 2026 and HydroCalc Plus on August 31, 2026.

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