# HVAC Load Calculator Manual J — BTU Sizing for Contractors

> HVAC load calculator for contractors, offering Manual J calculations with multiple accuracy levels. (iPhone/iPad app by Mike Watson.)

- Source: https://appshunter.io/ios/app/hvac-load-calculator-manual-j/id6758120488 (this page in markdown: same URL + `.md`)
- Developer: [Mike Watson](https://appshunter.io/developer/1848411021)
- Category: Utilities, Productivity
- Price: Free with in-app purchases (on sale, was $1.99)
- Rating: 4.80/5 from 34 App Store ratings · 2 written reviews indexed
- Age rating: 4+
- Requires: iOS 16.0 · 50 MB
- Languages: American English
- Released: 2026-02-02
- Data updated: 2026-08-25
- Monetization: free with in-app purchases
- User reviews in markdown: https://appshunter.io/ios/app/hvac-load-calculator-manual-j/id6758120488/reviews.md

## What is HVAC Load Calculator Manual J?

The Manual J HVAC Load Calculator is the one HVAC contractors actually want to use.

Stop overpaying for clunky, over-engineered calculators designed for engineers. HVAC Load Calculator brings professional Manual J calculations to your iPhone or iPad — clean, modern, offline-ready, and built for the field.

BUILT FOR HVAC PROFESSIONALS
Designed from scratch for techs in the field: large buttons you can tap with gloves on, fast calculations in the basement, and professional reports that win homeowner trust.

THREE LEVELS OF ACCURACY

Simple Mode – 8 inputs
Regional ZIP-code benchmarks and square-footage multipliers. Get an estimate in under 60 seconds with zero measurements. Perfect for quick quotes and initial sales conversations.

Moderate Mode – Standard Accuracy (Whole-House Block Load) – 15 inputs
Component-level factors: insulation quality, window types, foundation — with a conservative safety buffer. The sweet spot for standard replacement jobs.

Pro Mode – Professional Grade (Detailed Whole-House Block Load) – 16 inputs + pro overrides
Full MJ8 physics: altitude-adjusted density, solar load factors, CLTD daily-range lag, and separated duct analysis. Maximizes equipment life and comfort — often right-sizing by 1+ ton. Best for new construction, high-performance builds, and detailed equipment sizing.

MEASURE ROOMS WITH LiDAR — NEW
On LiDAR-equipped iPhone and iPad Pro models (iOS 16+), walk each room and the app measures it for you — floor area, ceiling heights, windows, and exterior walls flow straight into your load calculation. Review each room, adjust with a tap, apply. Your PDF gains a Room Measurements chapter with a sketch of every scanned room.

NOW AVAILABLE WORLDWIDE
US Mode – ZIP code lookup backed by a climate database covering nearly 28,000 ZIP codes
International Mode – Enter your city, country, and local design temperatures directly — no ZIP code required. Choose your climate zone and moisture regime, and the calculator handles the rest.
Metric Units – Toggle between Imperial and SI (kW, m², m³/h) throughout the app and PDF reports

WORKS IN THE FIELD
Offline-First – No signal in the basement? No problem. Everything runs locally on your device.
Auto-Save Projects – Every calculation saves automatically. Never lose your work.
iCloud Sync – Start a job on your iPhone, finish it on your iPad. Projects sync automatically across your devices.
Professional PDF Reports – Generate and share detailed load reports from your phone or tablet. Add client name, site address, and job number — every report is stamped with a revision number and date, so everyone knows it's the latest version.
Site Photo Documentation – Capture tagged photos, label by location and component, add notes, and include a professional photo appendix in your reports.
iPad & Tablet Support – Optimized layouts give you more room to work on-site or back at the office.

THE MATH YOU TRUST
Calculations follow ACCA Manual J 8th Edition methodology:
– Cooling BTU/hr (sensible and latent loads)
– Heating BTU/hr
– Recommended tonnage (rounded to 0.5 tons)
– Recommended furnace size (rounded to 5,000 BTU)
– Manual S-based equipment sizing guidance
– Kitchen/appliance heat gain per MJ8 Table 4
If a result looks unusual for the home's size, the app flags it before the report goes out.

WHY CONTRACTORS CHOOSE US
– Modern, intuitive interface that makes sense the first time you use it
– Dark mode and system theme support
– Fast performance, even on older devices
– Privacy-first: your data stays on your device and your own private iCloud — never our servers
– Free to download — try it on your first calculations before subscribing

PERFECT FOR
– HVAC contractors, installers, and service techs
– Sales teams quoting new systems
– Independent contractors building their business
– Home inspectors documenting HVAC systems

No account. No setup. Just open the app and get to work.

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

## Key features

- Multiple accuracy levels (Simple, Moderate, Pro)
- Offline-ready calculations
- Professional PDF report generation
- Site photo documentation
- International and US modes
- Metric unit support

## Pricing and in-app purchases

Base price: Free.

**Subscriptions**

| Subscription | Price | Period |
| --- | --- | --- |
| Annual Pro with Trial | $9.99 | per year |
| Pro License | $11.99 | per year |
| Annual Pro with Trial | $4.99 | per year |
| HVAC Load Calculator Pro | $19.99 | per year |
| HVAC Load Calculator Pro | $9.99 | per year |
| Annual Pro with Trial | $7.99 | per year |


## Recent user reviews (2 of 2)

All indexed reviews: https://appshunter.io/ios/app/hvac-load-calculator-manual-j/id6758120488/reviews.md

### 5/5 — It’s fast, it’s easy and from doing it manually, it’s actuate!

*2026-07-28*

The title says it all.

**Developer response:** Thank you for the great feedback! We plan to continue adding features to make it more useful to you and the rest of our users. 

Feel free to submit any ideas for new features to mike@hvacloadcalculator.online

### 1/5 — ONLY WORKS IN SIMPLE MODE

*2026-04-01*

If you try to add moderate inputs, like actual sq ft of windows per direction, it kicks out an error and asks you to reload app. This happened to me three times. I’m done. 😡 DO NOT DOWNLOAD! You DO NOT need the headache.

**Developer response:** Hello! We are sorry you ran into this issue! We connected over email yesterday and were able to push an update the same night to get everything working correctly for all users. We really appreciate you reaching out.

To catch issues like this faster in the future, we're adding an opt-in feature that lets you anonymously share bug reports. You were actually the first to pass along an issue, so your feedback made the app better for everyone. Thanks for taking the time.

## Frequently asked questions about HVAC Load Calculator Manual J

### What is HVAC Load Calculator Manual J?

HVAC Load Calculator Manual J is a mobile application designed for HVAC contractors to perform professional load calculations. It follows ACCA Manual J 8th Edition methodology for accurate heating and cooling load estimations.

### Does HVAC Load Calculator Manual J have ads?

No, HVAC Load Calculator Manual J does not contain advertisements. The app is free to download and use, with optional in-app purchases for advanced features and subscription plans.

### What are the different calculation modes in HVAC Load Calculator Manual J?

HVAC Load Calculator Manual J offers three modes: Simple Mode for quick estimates, Moderate Mode for standard jobs with component-level factors, and Pro Mode for full Manual J physics and detailed analysis.

### Can HVAC Load Calculator Manual J be used offline?

Yes, HVAC Load Calculator Manual J is an offline-first application. All calculations run locally on your device, meaning you can use it even without a signal, making it ideal for field work.

### What subscription plans are available for HVAC Load Calculator Manual J?

HVAC Load Calculator Manual J offers several subscription plans, including Annual Pro options starting at $4.99/P1Y with a 7-day free trial. There are also Pro versions available for $9.99/P1Y and $19.99/P1Y.

### What devices support HVAC Load Calculator Manual J?

HVAC Load Calculator Manual J is available for iPhone, iPad, and iPod. The app is optimized for different screen sizes, including specific layouts for iPads.

### How often is HVAC Load Calculator Manual J updated?

The latest version of HVAC Load Calculator Manual J is 1.9.8 (58), which was last updated on March 26, 2026. Updates typically include new features, performance improvements, and bug fixes.

### What is the age rating for HVAC Load Calculator Manual J?

HVAC Load Calculator Manual J has an age rating of 4+. This indicates it is suitable for users of all ages and does not contain content that would be inappropriate for children.

## Version history (last 5 releases)

### 1.20.0 — 2026-08-17

SCAN ROOMS WITH LiDAR (NEW)
Walk each room and your iPhone measures it for you. Floor area, ceiling heights, windows, and exterior walls flow straight into your load calculation — review every room, correct anything with a tap, and apply.

• Room Measurements chapter in the PDF report, with a floor-plan sketch for every scanned room
• Per-room ceiling heights, editable right on the scan card
• In-app scan guide with tips for clean captures
• Fix: clearing the four window-orientation fields now restores your total window area
• Fix: window U-factor and SHGC now display both decimals

Room scanning needs a LiDAR-equipped iPhone or iPad (Pro models) on iOS 16 or later. Everything else works on every device, same as always.

### 1.19.4 — 2026-08-14

What changed:
• Duct Adjustment now shows only actual duct loss. Window conduction, doors, and latent load appear as their own lines on the report.
• Air-tightness now affects the result. A measured blower-door number is never overridden, and tight homes generally calculate lower.
• Altitude correction is applied once, not twice. Heating loads at elevation (Denver and higher) were understated by around 5%.
• Sliding glass doors now carry realistic heat loss for heating, matching how cooling already treats them.

Also new:
• Attached Unit — for condos, townhouses, and apartments: mark which surfaces border another heated unit so they're not treated as exposed to the outdoors.
• Target Airflow shown alongside the recommended equipment size.
• Sun Exposure now states the adjustment it applies.
• Clearer furnace sizing messages when no catalog size fits the calculated range.
• A cleaner "How We Calculate" explainer in Settings.

### 1.16.5 — 2026-08-03

- Load breakdown now itemizes every component. Window conduction, doors, and latent load appear as separate lines on the cooling and heating tables, so the "Duct Adjustment" line shows only the actual duct loss.
- Target Airflow now appears on the results screen alongside the recommended equipment size.
- Sun Exposure now states its effect — the report shows the reduction it applies to window solar gain and notes that it's an app adjustment rather than a Manual J procedure.
- Infiltration figures carry a note (Moderate/Pro) when the displayed rate differs from the rate used in the calculation.

### 1.16.3 — 2026-08-01

- Indoor design temperatures — keep the Manual J standard (75° cooling / 70° heating) or set custom cooling (68–78°) and heating (62–75°) targets per project. Loads, equipment sizes, and reports all reflect your setpoints, with a clear callout whenever a design deviates from the Manual J defaults.
- Default temperatures in Settings — set your preferred design temps once and every new project starts with them; any project can still override.
- Reports now state the indoor design temperatures — every PDF prints the targets it was sized to, with a footnote when a homeowner preference was used.
- Duplicate a project — start the next job from a copy of an existing house without re-entering everything.
- Project search — quickly filter your project list by name.

### 1.13.0 — 2026-07-05

-Client & job details — add client name, site address, job number, and notes to any project; they appear on the PDF report automatically.
-Report revisions — reports are now stamped with the job number, revision (Rev 1, Rev 2…), and generation date, so everyone knows they're looking at the latest version.
-Input sanity check — if a calculated load looks unusually high or low for the floor area, the app quietly suggests double-checking your inputs (never shown on client reports).

## More apps by Mike Watson

- [Leafed - Private Book Tracker](https://appshunter.io/ios/app/leafed-private-book-tracker/id6754466418)
- [Water Damage Report Photo Docs](https://appshunter.io/ios/app/water-damage-report-photo-docs/id6758919407)
- [Spray Mix & Tank Calculator](https://appshunter.io/ios/app/spray-mix-and-tank-calculator/id6759580852)
- [A2L Safe Charge - Superheat](https://appshunter.io/ios/app/a2l-safe-charge-superheat/id6760899340)
- [Attentionly: ADHD Time Audit](https://appshunter.io/ios/app/attentionly-adhd-time-audit/id6761147386)

All apps by Mike Watson: https://appshunter.io/developer/1848411021

## Related topics

[manual j](https://appshunter.io/ios/topics/manual-j) · [hvac load calculator](https://appshunter.io/ios/topics/hvac-load-calculator) · [hvac load calculator manual j](https://appshunter.io/ios/topics/hvac-load-calculator-manual-j) · [hvac manual j](https://appshunter.io/ios/topics/hvac-manual-j) · [heat load calculator](https://appshunter.io/ios/topics/heat-load-calculator) · [hvac load](https://appshunter.io/ios/topics/hvac-load) · [hvac calculator load lite](https://appshunter.io/ios/topics/hvac-calculator-load-lite) · [hvac calculator heat](https://appshunter.io/ios/topics/hvac-calculator-heat) · [hvac calculator prox](https://appshunter.io/ios/topics/hvac-calculator-prox) · [hvac calculator load pro](https://appshunter.io/ios/topics/hvac-calculator-load-pro) · [triple j ductwork](https://appshunter.io/ios/topics/triple-j-ductwork)

---

*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 2026-08-25.*