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 Unlike expensive desktop software shoehorned onto mobile, we designed this from scratch for techs working in the field. Large buttons you can tap with gloves on. Fast calculations while standing in a basement. 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. Prevents undersizing while staying accessible for non-engineers. 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.

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 And if a result looks unusual for the home's size, the app quietly flags it so you can double-check your inputs before the report goes out. Tap "How Our Calculator Works" for a plain-English guide to every input and how it shapes your results.

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 – International professionals working in metric – 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/