Comparison

HVAC Formulator vs Hydronic

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

Head to head
About

HVAC Formulator

This app provides HVAC professionals with over 900 essential formulas and calculations for load calculations and system design. It supports both US and Metric units, offers instant switching, and includes 23 calculator categories and over 460 unit conversions. Designed for field use, it works offline and allows users to save and share results.

Highlights
  • Over 900 formulas and calculations
  • US & Metric unit support
  • 23 calculator categories
  • 460+ unit conversions
  • 8 temperature scales
  • Offline functionality
  • Save and share results
Features
Read full description

HVAC FORMULATOR is the essential tool for Heating, Ventilating, and Air Conditioning professionals. With over 900 formulas and calculations, it covers everything from basic load calculations to advanced system design — all in your pocket. US & METRIC SUPPORT — Switch instantly between US (Imperial) and Metric (SI) units. Results display in both systems so you always have the value you need. Input labels and conversions update automatically. 23 CALCULATOR CATEGORIES including: - Cooling Load — Sensible, latent, and total cooling calculations, tons, EER, COP, and sensible heat ratio - Fan Laws — Speed and diameter affinity laws for CFM, pressure, and horsepower - Duct Sizing — Velocity, round and rectangular sizing, equivalent diameter, aspect ratio - Ventilation Rate — ASHRAE 62.1 breathing zone, air changes per hour, exhaust fan sizing - Electrical — Ohm's Law, single and three-phase power, motor FLA, watts to BTU/h - Gas Laws — Boyle's, Charles's, Gay-Lussac's, Combined, and Ideal Gas Law - Psychrometrics — Bypass factor, mixed air temperature, percent outside air, dew point - Hydronic Formulas — Heat transfer, flow rate, pipe velocity, expansion tank, Cv coefficient - Boiler — Efficiency calculations, BTU output, heat absorption - Refrigeration — Tonnage output, compression ratio, mass flow rate, COP - Ductwork — Velocity, velocity pressure, total pressure, equivalent round - Airside — Sensible heat, latent heat, total heat (US and Metric) - Piping — Pipe area, weight, friction loss, expansion, Hazen-Williams, 70+ formulas - Steam — Condensate loads, fuel calculations, steam flow - Pump Laws — Break horsepower, suction head, pump affinity laws - Energy — Fuel values for oil, gas, coal, propane, ethanol, and more - Heating Design — Electric heating, baseboard, radiant ceiling, boiler capacity, hydronic snow melting - Heating Requirement — Insulation-based load calculations - Humidity — Specific humidity, relative humidity, sensible and latent heat - Loads — Temperature loads, heat gains from lights, equipment, and machines - Temperature — Mixed air, liquid mixing, final temperature calculations - Waterside System — Total heat, evaporator and condenser flow rates - Air Change Rate — Air changes per hour, air flow rate 460+ UNIT CONVERSIONS across 16 categories: Metric, Pressures, BTU, Linear, Square, Cubic, Liquid Measures, Weights, Flows, Power, Horsepower, Watts, Hydraulic, Ft-Lbs, Sand/Volume, and HVAC-specific conversions. 8 TEMPERATURE SCALES — Convert between Celsius, Fahrenheit, Kelvin, Rankine, Reaumur, Newton, Delisle, and Romer. BUILT FOR PROFESSIONALS: - Search across all 900+ formulas instantly - Mark favorites for quick access - Save calculation history with full breakdown - Share and export results - Clean, fast interface designed for field use - Works offline — no internet required HVAC FORMULATOR is a professional-grade tool built for HVAC technicians, engineers, contractors, and students. New formulas and features are added regularly.

About

Hydronic

Features
Read full description

Hydronic HVAC Toolkit App is a tool that provides most common info on a range of HVAC equipment manufactured by Modine (unit heaters – gas-fired, steam/hot-water, electric), Koldwave (portable ACs), Reflected Heat Design (infrared tube heaters), Radiant Electric Heat (infrared), Continental Fans, ThermoTek (kitchen heating & ventilation systems), RBI (boilers / hot water heaters), KN Series (cast iron boilers). You can find info such as combustion, electrical, venting, dimensions, weight, clearance to combustibles, common parts list, etc. on Modine unit heaters; competitive cross-reference for infrared tube heaters and more. Also, new in this revision is a Make-Up Air Selection Form that allows you to quickly submit specs and pics for a reliable, application accurate quote. You also receive specs submitted via the form, emailed to you for your records. Hydronic Toolkit app is a quick reference guide for engineers specifying Modine unit heaters in HVAC projects, Modine re-sellers (counter sales, outside sales) selling Modine unit heaters and contractors installing them. It allows quick access to Modine unit heater specs on-site or when you are not in front of a PC/laptop. At your fingertips is info available on all these Modine unit heaters – a) Eleven gas-fired models, sizes available from 30,000-400,000 Btu/hr. input b) Seven steam/hot-water models, sizes available from 18,000-952,000 Btu/hr. (@ 2psi steam) c) Four electric models, sizes available from 5-50 kW

Screenshots

HVAC Formulator4 screens
Hydronic3 screens

Verdict

The call

The clearest difference is price: Hydronic at Free against HVAC Formulator's $4.99. Hydronic also leads on in-app purchases (none vs 1) and update cadence (weekly vs every 2 months). On ads 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

Hydronic is free to download; HVAC Formulator costs $4.99 up front. HVAC Formulator sells 1 one-off in-app purchase. Hydronic asks for nothing beyond the download.

UpkeepUpdate frequency

HVAC Formulator ships an update every 2 months, Hydronic weekly. The most recent releases landed on October 18, 2026 and October 6, 2026 respectively.

Scorecard4 real differences · 6 level
HVAC Formulator versus Hydronic: the parameters behind the verdict, then further details
ParameterHVAC FormulatorHydronic
Price$4.99Free — better
Rating2.0 (1 ratings) — better—
Positive reviews9.1% of reviews—
Number of ratings1 — better—
Update frequencyEvery 2 monthsWeekly — better
AdsNoNo
In-app purchasesYesNo — better
MonetizationPaid—
DevicesiPhone, iPadiPhone, iPod
Requires iOS18.612.1 — better
Further details — not scored
Size73 MB2 MB
Age rating4+4+
DeveloperHistorycentral.comPhilip Antecol

In-app purchases

1 purchases

HVAC Formulator

One-time1
  • HVAC Pro$3.99
None

Hydronic

No in-app purchases

Questions

Is HVAC Formulator free?
HVAC Formulator costs $4.99, and also offers in-app purchases.
Is Hydronic free?
Hydronic is free to download, with no in-app purchases.
Do HVAC Formulator or Hydronic have ads?
Neither HVAC Formulator nor Hydronic shows ads.
Which is updated more often, HVAC Formulator or Hydronic?
HVAC Formulator ships an update every 2 months, and Hydronic weekly. Most recently, HVAC Formulator was updated on October 18, 2026 and Hydronic on October 6, 2026.

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