# HVAC Sizer — Fast duct and pipe sizing > HVAC duct and pipe sizing calculator for engineers and contractors. (iPhone/iPad app by Joshua Wood.) - Source: https://appshunter.io/ios/app/hvac-sizer/id6826033722 (this page in markdown: same URL + `.md`) - Developer: [Joshua Wood](https://appshunter.io/developer/1502037717) - Category: Utilities, Reference - Price: $4.99 - Rating: 5.00/5 from 2 App Store ratings · 1 written reviews indexed - Age rating: 4+ - Requires: iOS 18.0 · 4 MB - Languages: American English - Released: 2026-10-23 - Data updated: 2026-10-29 - Monetization: paid - User reviews in markdown: https://appshunter.io/ios/app/hvac-sizer/id6826033722/reviews.md ## What is HVAC Sizer? HVAC Sizer sizes ductwork and piping as fast as you can type a flow. Enter the airflow, GPM or lb/h, and the right size appears instantly, checked against your friction and velocity limits. Built by a mechanical engineer for engineers, designers and contractors who size duct and pipe every day and want an answer in seconds, not a spreadsheet. DUCTWORK • Round, rectangular and flat oval • One-tap presets for LP supply, MP supply and return/exhaust, each with its own friction and velocity limits • Rectangular and flat oval options within your maximum aspect ratio, with the least-sheet-metal size marked • Lock a depth or minor axis, up to 288 inches, for tight ceiling space; the app solves the other dimension • Darcy-Weisbach friction with the Colebrook equation, corrected for altitude and air temperature • Equivalent diameter, velocity and friction for every option PIPING • Hydronic: water, ethylene glycol or propylene glycol from 0 to 100%, at any fluid temperature, with viscosity, specific gravity and freezing point shown • Domestic water: cold and hot, friction in psi per 100 ft • Steam: saturated steam at any pressure from vacuum to 600 psig, with limits that switch automatically between low and high pressure • Steel Sch 40/80, copper K/L/M, PEX, PVC, CPVC and HDPE, with true inside diameters • Separate velocity limits for 2 inches and under and over 2 inches CONDENSATE • Two-phase returns sized on flash steam, with flash fraction, flash steam and liquid shown • Gravity liquid lines sized with Manning's equation for your slope and maximum depth of flow SEE THE MARGIN, NOT JUST THE SIZE Every result shows how close it is to each limit, colored green, amber or red. Nearby sizes are listed, so you can step up or down with one tap. The app tells you whether friction or velocity governs. BATCH SIZING • Add any result to a running schedule with a tag such as S-1 or P-12; tags count up automatically • Keep separate schedules for each project • Tap a row to add notes, or reopen it in its sizer to re-size • Export a CSV, or copy the schedule and paste it straight into Excel YOUR STANDARDS, SAVED Every default can be changed and is saved on your device: friction and velocity limits, materials, glycol mix, fluid temperatures, aspect ratio, steam pressure split, condensate slope and more. Switch between IP and SI units at any time. MADE FOR SPEED • Number pad on every field, with Done to dismiss it; tapping a field selects its value so you can just type • Works on iPhone, iPad and iPhone Duo, folded or unfolded, with side-by-side inputs and results on larger screens • Light and dark mode • No account, no ads, no internet connection needed Results are engineering estimates based on standard methods and published fluid properties. Always verify final designs against applicable codes, standards and manufacturer data. ## Key features - Instant duct and pipe sizing - Friction and velocity limit checks - Support for various materials (steel, copper, PEX, PVC) - Batch sizing and project scheduling - Customizable defaults and unit systems - Offline functionality ## Is HVAC Sizer safe? Not enough ratings yet to assess HVAC Sizer. ## Is HVAC Sizer legit? HVAC Sizer appears legitimate, with a few gaps. The AppsHunter Legitimacy Score for HVAC Sizer is 70 out of 100 points across 7 verification signals from App Store and developer data. ## Recent user reviews (1 of 1) All indexed reviews: https://appshunter.io/ios/app/hvac-sizer/id6826033722/reviews.md ### 5/5 — Great Sizing App! *2026-10-23* This is a great app for sizing ductwork, and piping. Like the UI too! ## Frequently asked questions about HVAC Sizer ### What is HVAC Sizer used for? HVAC Sizer is a utility app designed to quickly calculate the appropriate sizes for ductwork and piping based on specified flow rates, friction, and velocity limits. It provides engineering estimates for HVAC professionals. ### What types of ductwork and piping can HVAC Sizer size? HVAC Sizer supports round, rectangular, and flat oval ductwork, as well as hydronic piping (water, glycol), domestic water, and steam piping. It accommodates various materials like steel, copper, PEX, PVC, and CPVC. ### Does HVAC Sizer require an internet connection? No, HVAC Sizer does not require an internet connection to function. It is designed to work offline, making it convenient for use in the field or areas with limited connectivity. ### Can I save my sizing calculations with HVAC Sizer? Yes, HVAC Sizer allows you to add results to a running schedule for each project, with automatic tag counting. You can also add notes to specific entries and export schedules as CSV files. ### What are the pricing details for HVAC Sizer? HVAC Sizer is a paid application, available for a one-time purchase of $4.99. This price grants you access to all its features without any recurring subscription fees. ### Does HVAC Sizer have ads? No, HVAC Sizer is ad-free. The developer has stated that the app contains no advertisements, ensuring an uninterrupted user experience. ### On which devices can I use HVAC Sizer? HVAC Sizer is compatible with Apple devices, specifically the iPhone and iPad. It is optimized for various screen sizes, including folded iPhones. ### How often is HVAC Sizer updated? HVAC Sizer was last updated on October 25, 2026, with version 1.1. While specific update frequency isn't detailed, this indicates ongoing support and potential for future enhancements. ## Version history (last 2 releases) ### 1.1 — 2026-10-25 Added pump and fan sizing and some other hydronic goodies! ### 1.0 — 2026-10-23 No release notes. ## More apps by Joshua Wood - [Score Keep!](https://appshunter.io/ios/app/score-keep/id6449625763) - [Calc89](https://appshunter.io/ios/app/calc89/id6826749082) All apps by Joshua Wood: https://appshunter.io/developer/1502037717 --- *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 2026-10-29.*