# CaptiveAire Toolbox — HVAC ENGINEERING TOOLBOX > Pocket HVAC and building systems engineering calculators with industry-standard formulas. (iPhone/iPad app by CaptiveAire Systems, Inc..) - Source: https://appshunter.io/ios/app/captiveaire-toolbox/id6765656560 (this page in markdown: same URL + `.md`) - Developer: [CaptiveAire Systems, Inc.](https://appshunter.io/developer/1896026735) - Category: Utilities, Reference - Price: Free - Rating: 5.00/5 from 1 App Store ratings - Age rating: 4+ - Requires: iOS 16.0 · 70 MB - Released: 2026-05-07 - Data updated: 2026-08-29 - Monetization: free - User reviews in markdown: https://appshunter.io/ios/app/captiveaire-toolbox/id6765656560/reviews.md ## What is CaptiveAire Toolbox? 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. ## Key features - 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 ## Frequently asked questions about CaptiveAire Toolbox ### What types of cooling calculations does CaptiveAire Toolbox offer? CaptiveAire Toolbox offers several cooling calculations, including Total Cooling Load (enthalpy-based with humidity), Sensible Cooling Load, Latent Cooling Load, SEER, and Cost of Cooling. It also provides Tons to BTU/hr conversions and specific modes like DX/MPU Cooling. ### Can CaptiveAire Toolbox help with heating system calculations? Yes, CaptiveAire Toolbox includes heating calculations for BTU output of direct and indirect fired heaters, input/output BTU/hr for IBT systems, and temperature rise from BTU and CFM. It also calculates Heat Pump capacity with airflow and outdoor temperature adjustments. ### Does CaptiveAire Toolbox include electrical sizing tools? Yes, CaptiveAire Toolbox features electrical sizing tools based on NEC Table, including calculations for MCA and MOCP for motor circuits, and amperage from horsepower. This helps ensure compliance with electrical codes. ### What reference data is available in CaptiveAire Toolbox? The app provides ASHRAE Weather Station data with an autocomplete address search, returning heating and cooling design temperatures, solar irradiance, and wind speeds. It also includes an interactive Psychrometric Chart with property calculations. ### How does CaptiveAire Toolbox explain its formulas? Each calculator in CaptiveAire Toolbox includes accessible formula and variable definitions from the title bar. Tapping the info icon reveals the exact equation used to derive the result, promoting transparency. ### Is CaptiveAire Toolbox available on Android devices? CaptiveAire Toolbox is currently supported on iPhone and iPad devices. Information regarding Android availability is not provided in the current data. ### How often is CaptiveAire Toolbox updated? The latest version of CaptiveAire Toolbox is 1.4.1, which was last updated on August 21, 2026. The release date was May 7, 2026, suggesting a relatively frequent update cycle. ### Does CaptiveAire Toolbox have ads? No, CaptiveAire Toolbox is ad-free. The description explicitly states 'No tracking, no ads, no account required,' ensuring an uninterrupted user experience. ## Version history (last 5 releases) ### 1.4.1 — 2026-08-21 Bug fixes and improvements ### 1.4.0 — 2026-08-03 Bug fixes and improvements ### 1.3.7 — 2026-07-17 Bug fixes and improvements ### 1.3.6 — 2026-07-15 Bug fixes and improvements ### 1.3.5 — 2026-07-11 Bug fixes and improvements --- *Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-08-29.*