CaptiveAire Toolbox vs UnitDown AI

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.

Commercial HVAC diagnostics, equipment memory, and field documentation in one place. UnitDown AI helps commercial HVAC technicians turn symptoms, measurements, alarms, and nameplate data into structured troubleshooting guidance—then carry that context into the next visit. DIAGNOSE WITH MORE CONTEXT Describe the problem in technician language. UnitDown AI organizes likely causes, first checks, meter and instrument checks, alternative faults, recommended actions, and risks to consider. SCAN EQUIPMENT NAMEPLATES Capture equipment data from a nameplate, review the extracted details, and save the unit for future service calls. KEEP EQUIPMENT HISTORY TOGETHER Build a service timeline with diagnostics, repairs, preventive maintenance, measurements, photos, parts, recommendations, and technician notes. RUN THE JOB FROM THE FIELD Create jobs, document progress, track required details, and keep customer sites and equipment organized from arrival through closeout. PREPARE BEFORE DISPATCH Use equipment history and van inventory to reduce forgotten parts and repeat trips. BUILT FOR COMMERCIAL HVAC Support for rooftop units, chillers, refrigeration, electrical faults, heating failures, airflow problems, economizers, compressors, and control systems. UnitDown AI provides informational decision support. Always follow lockout/tagout procedures, use proper PPE and approved instruments, verify conditions, and follow manufacturer service literature. Do not rely on UnitDown AI for emergency, life-safety, or final repair decisions. Some features require a UnitDown AI Pro auto-renewing subscription. Subscription terms and pricing are shown before purchase. Manage or cancel through your Apple ID subscription settings. Privacy Policy: https://unitdown.org/privacy Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/