HVAC SizerSupport
How can I help?
Questions, bug reports and feature ideas for HVAC Sizer go straight to the developer.
Contact support
For a bug, it helps to include your device, iOS version and the inputs that gave the unexpected result.
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About the app
AppHVAC Sizer 1.0 for iPhone and iPad (iOS 18 or later)
DeveloperIndependent developer and mechanical engineer
ContactUse the form on this page.
Frequently asked questions
Does the app need an internet connection or an account?
No. HVAC Sizer works fully offline, with no sign-in, ads or subscriptions.
Where are my schedules and settings stored?
Only on your device. They’re not sent anywhere, and the developer can’t see them. Deleting the app deletes them, so export any schedule you want to keep first.
How do I move my schedules to a new iPhone or iPad?
The app doesn’t sync between devices. Restoring your old device’s iCloud or computer backup to the new one brings your schedules and settings along. You can also export each schedule as a CSV from the Schedule tab.
How do I get a schedule into Excel?
On the Schedule tab, tap Copy for Excel and paste into a spreadsheet, or tap Export CSV to save or send a file.
How do I switch between IP and SI units?
Open Settings and choose IP or SI under General. You can switch at any time.
What methods does the app use?
Darcy-Weisbach friction with the Colebrook-White friction factor; the Huebscher equivalent diameter for rectangular duct and the ASHRAE equivalent diameter for flat oval; air density corrected for altitude and temperature; IAPWS-IF97 and IAPWS-95 properties for steam and water; Melinder glycol properties (flagged as extrapolated above 60% by mass); flash steam for two-phase condensate and Manning’s equation for gravity lines.
Can I use the results for final design?
Results are engineering estimates based on standard methods and published fluid properties. Always verify final designs against applicable codes, standards and manufacturer data.