Azure ECM vs CaptiveAire Toolbox
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Azure ECM
This utility app enables precise adjustment of individual Azure motor speed taps to optimize system CFM. It allows for single-tap adjustments on energized taps, with specific limitations on factory-locked taps. Users can reduce torque for lower speeds by selecting alternative taps.
- Adjust individual Azure motor speed taps
- Optimize system CFM
- Single-tap adjustment on energized taps
- Reduce torque for lower speeds
- Supports iPhone and iPad
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This app allows the individual Azure motor speed taps to be adjusted for optimizing system CFM.Azure blower motor adjustments can be made to only one tap at a time; the tap being energized is the tap that can be adjusted. Note: if equipped, a 625RPM constant fan tap is factory locked and cannot be adjusted. For lower speeds, select another tap and reduce torque.
CaptiveAire Toolbox
This app provides over 40 HVAC and building-systems engineering calculators. It's designed for field use, offering standard industry formulas for cooling, heating, ventilation, electrical sizing, and more. Access detailed formula definitions and reference data.
- 40+ HVAC engineering calculators
- Cooling and heating load calculations
- Ventilation and airflow tools
- Electrical sizing and motor circuits
- Duct and piping pressure drop
- Reference data and psychrometric chart
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The CaptiveAire Toolbox puts 40+ HVAC and building-systems engineering calculators in your pocket. Designed for engineers, contractors, and technicians, every formula uses standard industry references (ASHRAE, AMCA, NEC), sized so you can run sanity checks in the field instead of pulling out a laptop. Cooling: Total Cooling Load (enthalpy-based with humidity), Sensible Cooling Load, Latent Cooling Load, SEER, Cost of Cooling, Tons to BTU/hr conversions, DX/MPU Cooling, Evaporative Cooling, DMUA mode logic, Cooling Density Factor. Heating: BTU output for direct and indirect fired heaters, Input and Output BTU/hr for IBT systems, Temperature Rise from BTU and CFM, Heat Pump capacity with airflow and outdoor temperature adjustment, Reheat Coil leaving conditions, Manifold Pressure for natural gas and LP, Heating Density Factor. Ventilation and Airflow: Room Volume CFM, Sensible Heat CFM, Cooling Load CFM, Duct Velocity CFM, Outdoor Air Load (sensible plus latent), Psychrometric properties from dry bulb plus RH or wet bulb, Fan Energy Index per AMCA 208, Motor Adjusted Frequency for VFDs, ERV ROI Calculator with degree-day economics. Electrical Sizing: Wire Size per NEC Table, MCA and MOCP for motor circuits, Amperage from horsepower. Piping and Structural: Round Duct Sizing using Darcy-Weisbach and Colebrook-White, Duct Velocity and Friction, Piping Pressure Drop with fittings equivalent length, Pitched Roof curb height variation. Valve and Flow Sizing: Kv from flow rate, flow rate from Kv, pressure drop from Kv, Cv to Kv conversion, Heat Load to Flow Rate for water and glycol. Reference: ASHRAE Weather Station data with autocomplete address search, returning heating and cooling design temperatures, solar irradiance, wind speeds, and monthly design-day temperatures. Interactive Psychrometric Chart with property calculations. Modern HVAC versus Traditional Rooftop Unit comparison. Each calculator includes the formula and variable definitions accessible from the title bar. Tap the info icon to see exactly what equation drives the result. Built by the engineering team at CaptiveAire Systems. No tracking, no ads, no account required.
Screenshots
Verdict
The clearest difference is rating: CaptiveAire Toolbox at 5.0 against Azure ECM's 4.2. CaptiveAire Toolbox also leads on update cadence (every 6 days vs every 2 months). Azure ECM's advantage is ratings volume (5 vs 1) and iOS requirement (9.0 vs 16.0). On price, 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
Both are free to download. Neither carries in-app purchases, so what you see is what you pay.
CaptiveAire Toolbox holds the better App Store score, 5.0 against 4.2. That said, the two scores are not equally well evidenced: Azure ECM has 5 ratings behind it against 1, so its average is the more settled of the two.
Azure ECM ships an update every 2 months, CaptiveAire Toolbox every 6 days. The most recent releases landed on October 8, 2026 and October 5, 2026 respectively.
| Parameter | Azure ECM | CaptiveAire Toolbox |
|---|---|---|
| Price | Free | Free |
| Rating | 4.2 (5 ratings) | 5.0 (1 ratings) — better |
| Positive reviews | 100.0% of reviews | — |
| Number of ratings | 5 — better | 1 |
| Update frequency | Every 2 months | Every 6 days — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Free | Free |
| Devices | iPhone, iPad, iPod — better | iPhone, iPad |
| Requires iOS | 9.0 — better | 16.0 |
| Further details — not scored | ||
| Size | 38 MB | 71 MB |
| Age rating | 4+ | 4+ |
| Developer | Zhongshan Broad-Ocean Motor Co., Ltd. | CaptiveAire Systems, Inc. |
Customer experience
Azure ECM
CaptiveAire Toolbox
In-app purchases
Azure ECM
No in-app purchases
CaptiveAire Toolbox
No in-app purchases
Questions
Is Azure ECM free?
Is CaptiveAire Toolbox free?
Which has better reviews, Azure ECM or CaptiveAire Toolbox?
Do Azure ECM or CaptiveAire Toolbox have ads?
Which is updated more often, Azure ECM or CaptiveAire Toolbox?
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