Comparison

HVAC Formulator vs Heat Engineer

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

Heat Engineer

This app assists heating engineers and surveyors in collecting property data for heating system installations. It supports heat loss reports for various technologies and includes tools for sound assessments and quick estimations. Data is automatically saved for later review and amendment.

Highlights
  • Heat loss survey for BS EN 12831, CIBSE, and MCS standards
  • MCS 020 sound assessment for Air Source Heat Pumps
  • Quick heat loss estimator tool
  • Automatic data saving and history for amendments
  • Room-by-room heat loss calculation
  • Photo capture for rooms and installation locations
  • Fuel comparisons and running cost calculations
Features
Read full description

Heat Engineer Software helps heating engineers and surveyors capture property information on site, carry out heat loss surveys and assess air source heat pump sound levels. From a quick estimate to a detailed room-by-room survey (3D LiDAR scanning), gather the information you need for heat pump and conventional heating system design. Work from your iPhone or iPad, then continue with your project in the Heat Engineer desktop platform. ROOM-BY-ROOM HEAT LOSS SURVEYS Capture the property details needed for heat loss calculations designed to follow BS EN 12831-1:2017, the CIBSE Domestic Heating Design Guide and relevant MCS requirements. • Create rooms using preset or custom names. • Record room dimensions, building materials and construction details. • Select materials from the built-in library or enter custom descriptions and U-values. • Record walls, floors, windows, doors, ceilings and roofs. • Capture complex room shapes and vaulted ceilings using illustrated profiles. • Record existing radiator types and dimensions to support emitter assessment. • Add photographs of rooms and proposed installation locations. • Continue your survey in the desktop platform to review calculations and produce detailed reports. CHOOSE HOW YOU MEASURE Use a tape measure or laser measure and enter your measurements, or use built-in LiDAR scanning on a compatible iPhone or iPad to capture room dimensions and layouts. Choose the survey method that suits the property and the equipment you have available. LiDAR scanning requires a compatible device with a LiDAR sensor. FLOOR PLANS AND LIDAR SCANNING Bring your survey to life with a visual layout of the property. • Scan rooms using supported LiDAR devices. • View captured rooms and layouts. • See room dimensions and radiator locations within your floor plans. • Export 2D floor plans to PDF for use alongside your project documentation. WHOLE-HOUSE HEAT LOSS AND QUICK ESTIMATES Assess a property before progressing to a detailed room-by-room survey. Use whole-house heat loss and quick estimation tools to support early discussions, initial project assessments and quotation preparation. Preliminary estimates help you get started. Complete a detailed room-by-room calculation to support final heating system and emitter design. AIR SOURCE HEAT PUMP SOUND ASSESSMENTS Carry out sound assessments to support assessment of the noise requirements associated with permitted development. • Record the proposed heat pump manufacturer and model. • Enter the manufacturer’s A-weighted sound power level. • Record the assessment position and add supporting photographs. • Review the assessment result. • Return to an assessment to update equipment details or site information. • Produce a PDF assessment report for your project records. A sound assessment addresses noise criteria; other planning requirements may also apply. CONNECTED FROM SITE TO DESKTOP Keep your mobile survey and desktop project connected with the updated Heat Engineer platform. Save your work, revisit surveys and assessments, and continue adding information as the project develops. Capture details on site, then use the desktop platform for further design work and reporting. GET STARTED A Heat Engineer account is required. Visit our website to create an account, explore the platform and watch our training videos

Screenshots

HVAC Formulator4 screens
Heat Engineer4 screens

Verdict

The call

The clearest difference is review sentiment: Heat Engineer at 79% against HVAC Formulator's 9%. Heat Engineer also leads on price (Free vs $4.99) and iOS requirement (16.4 vs 18.6). On update cadence, ads, in-app purchases 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

Heat Engineer is free to download; HVAC Formulator costs $4.99 up front. HVAC Formulator sells 1 one-off in-app purchase and Heat Engineer sells 1 one-off in-app purchase. Whichever you choose, the download price is not the number that matters.

UpkeepUpdate frequency

Both ship on a similar rhythm, roughly every 2 months. The most recent releases landed on October 6, 2026 and October 2, 2026 respectively.

Scorecard4 real differences · 6 level
HVAC Formulator versus Heat Engineer: the parameters behind the verdict, then further details
ParameterHVAC FormulatorHeat Engineer
Price$4.99Free — better
Rating2.0 (1 ratings) — better—
Positive reviews9.1% of reviews78.9% of reviews — better
Number of ratings1 — better—
Update frequencyEvery 2 monthsEvery 2 months
AdsNoNo
In-app purchasesYesYes
MonetizationPaidFree — better
DevicesiPhone, iPadiPhone, iPad
Requires iOS18.616.4 — better
Further details — not scored
Size73 MB203 MB
Age rating4+4+
DeveloperHistorycentral.comHeat Engineer Software Ltd

Customer experience

HVAC Formulator

All ratings1 ratings
Positive0.0%
Neutral0.0%
Negative100.0%
Written reviews11 reviews
Positive9.1%
Neutral18.2%
Negative72.7%

Heat Engineer

Written reviews19 reviews
Positive78.9%
Neutral0.0%
Negative21.1%

In-app purchases

1 purchases

HVAC Formulator

One-time1
  • HVAC Pro$3.99
1 purchases

Heat Engineer

One-time1
  • MCS 020 PDF Report Token$2.99

Questions

Is HVAC Formulator free?
HVAC Formulator costs $4.99, and also offers in-app purchases.
Is Heat Engineer free?
Heat Engineer is free to download, with in-app purchases available.
Do HVAC Formulator or Heat Engineer have ads?
Neither HVAC Formulator nor Heat Engineer shows ads.
Which is updated more often, HVAC Formulator or Heat Engineer?
HVAC Formulator ships an update every 2 months, and Heat Engineer every 2 months. Most recently, HVAC Formulator was updated on October 6, 2026 and Heat Engineer on October 2, 2026.

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