# BaseCalc HVAC Calculator — BTU CFM Duct Calculator

> BTU CFM Duct Calculator (iPhone/iPad app by BASEMAPPED LLC.)

- Source: https://appshunter.io/ios/app/basecalc-hvac-calculator/id6786116451 (this page in markdown: same URL + `.md`)
- Developer: [BASEMAPPED LLC](https://appshunter.io/developer/1896354976)
- Category: Utilities, Business
- Price: Free with in-app purchases
- Age rating: 4+
- Requires: iOS 16.4 · 54 MB
- Languages: American English
- Released: 2026-07-22
- Data updated: 2026-07-31
- User reviews in markdown: https://appshunter.io/ios/app/basecalc-hvac-calculator/id6786116451/reviews.md

## What is BaseCalc HVAC Calculator?

BaseCalc HVAC Calculator is an HVAC calculator for field math, worksheets, materials, and saved calculation history. Run BTU, CFM, duct sizing, airflow, psychrometrics, manufacturer-data refrigerant checks, planning load, hydronics, and other HVAC calculator arithmetic on site, then save the result for the job.

18 CALCULATORS FOR DAILY FIELD WORK
• BTU ↔ Tons — convert between BTU/hr and refrigeration tons.
• CFM from BTU — airflow from load and temperature rise/drop.
• BTU from CFM — load from airflow and temperature difference.
• Duct Sizing — round and rectangular duct from CFM and velocity.
• Air Velocity — velocity from CFM and cross-sectional area.
• Psychrometrics — total, sensible, and latent BTU/hr estimates at standard atmospheric pressure.
• Refrigerant Lines — check entered manufacturer line data against an entered equivalent-length limit.
• Superheat / Subcooling — record the exact target supplied by the equipment manufacturer.
• Room Load — preliminary area-factor planning math using your supplied factor; not Manual J.
• Heat Pump Balance — interpolate a bracketed balance point from entered manufacturer capacity data.
• Hydronics — BTU, GPM, and ΔT relationships.
• Mixed Air — mixed-air temperature from outdoor and return air.
• Air Changes — ACH from CFM and room volume.
• Evaporative Cooling — supply temperature and sensible air-side estimate.
• Filter Velocity — filter face velocity; use manufacturer data for pressure drop.
• O₂ Excess Air — theoretical dry-flue-gas dilution estimate from measured O₂; not a safety result.
• Refrigerant Weight — additional charge from an entered manufacturer allowance and rate.
• Outdoor Airflow — breathing-zone airflow arithmetic from user-supplied per-person and per-area rates.

EVERY RESULT IS EXPLAINED
• Explicit input validation, assumptions, and calculation boundaries.
• Final arithmetic and a calculation breakdown where the supplied data supports one.
• Saved local history so you keep a job-site record.

JOB RECORDS, MATERIALS, AND WORKSHEETS
• Save job contacts with site notes.
• Build job worksheets with scope, quantities, and site notes.
• Export worksheet PDFs for internal handoff or customer context.
• Plan common pull-list items before rough-in, service, and closeout.
• Send the finished billing handoff to SpeakSheet for the final invoice.

DEVICE-LOCAL FOR THE FIELD
• Works offline by default.
• No BaseCalc account or cloud sync.
• Job contacts, worksheets, settings, and calculation history use the app's local storage.
• Subscription status is checked through RevenueCat; exports leave the app only when you choose to share them.
• No third-party advertising SDK or third-party ads in this release.
• Dark and light themes with a high-contrast job-site interface.

BaseCalc HVAC is a professional reference tool. Always verify against current industry standards, manufacturer data, and local codes. The authority having jurisdiction has the final say.

Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

## Pricing and in-app purchases

Base price: Free.

**Subscriptions**

| Subscription | Price | Period |
| --- | --- | --- |
| HVAC Pro Monthly | $7.00 | per month |
| HVAC Pro Yearly | $50.00 | per year |



## Version history (last 1 release)

### 1.0.0 — 2026-07-22

No release notes.

## More apps by BASEMAPPED LLC

- [SpeakSheet Voice Invoice](https://appshunter.io/ios/app/speaksheet-voice-invoice/id6767040862)
- [BaseCalc Electric Calculator](https://appshunter.io/ios/app/basecalc-electric-calculator/id6782200021)
- [BaseCalc Plumbing Calculator](https://appshunter.io/ios/app/basecalc-plumbing-calculator/id6786117253)

All apps by BASEMAPPED LLC: https://appshunter.io/developer/1896354976

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*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 2026-07-31.*