HVAC Formulator vs Engage by FieldPulse
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
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.
- Over 900 formulas and calculations
- US & Metric unit support
- 23 calculator categories
- 460+ unit conversions
- 8 temperature scales
- Offline functionality
- Save and share results
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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.
Engage by FieldPulse
Manage all your customer communication in one place. This app integrates phone calls, text messaging, and voicemail for streamlined customer interactions.
- Integrated phone system
- Manage customer interactions
- Phone calls
- Text messaging
- Voicemail management
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Engage is a fully integrated phone system to manage your customer interactions, including phone calls, text messaging, voicemail, and more.
Screenshots
Verdict
The clearest difference is price: Engage by FieldPulse at Free against HVAC Formulator's $4.99. Engage by FieldPulse also leads on rating (3.6 vs 2.0) and in-app purchases (none vs 1). 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
Engage by FieldPulse is free to download; HVAC Formulator costs $4.99 up front. HVAC Formulator sells 1 one-off in-app purchase. Engage by FieldPulse asks for nothing beyond the download.
Engage by FieldPulse holds the better App Store score, 3.6 against 2.0. That said, the two scores are not equally well evidenced: Engage by FieldPulse has 18 ratings behind it against 1, so its average is the more settled of the two. Written reviews point the same way: 9% of HVAC Formulator's written reviews are positive against 40% of Engage by FieldPulse's.
HVAC Formulator ships an update every 2 months, Engage by FieldPulse every 3 weeks. The most recent releases landed on October 31, 2026 and November 3, 2026 respectively.
| Parameter | HVAC Formulator | Engage by FieldPulse |
|---|---|---|
| Price | $4.99 | Free — better |
| Rating | 2.0 (1 ratings) | 3.6 (18 ratings) — better |
| Positive reviews | 9.1% of reviews | 40.0% of reviews — better |
| Number of ratings | 1 | 18 — better |
| Update frequency | Every 2 months | Every 3 weeks — better |
| Ads | No | No |
| In-app purchases | Yes | No — better |
| Monetization | Paid | Free — better |
| Devices | iPhone, iPad | iPhone, iPad, iPod — better |
| Requires iOS | 18.6 | 15.1 — better |
| Further details — not scored | ||
| Size | 73 MB | 82 MB |
| Age rating | 4+ | 4+ |
| Developer | Historycentral.com | Flicent Inc |
Customer experience
HVAC Formulator
Engage by FieldPulse
In-app purchases
HVAC Formulator
- HVAC Pro$3.99
Engage by FieldPulse
No in-app purchases
Questions
Is HVAC Formulator free?
Is Engage by FieldPulse free?
Which has better reviews, HVAC Formulator or Engage by FieldPulse?
Do HVAC Formulator or Engage by FieldPulse have ads?
Which is updated more often, HVAC Formulator or Engage by FieldPulse?
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