Press kit
HVAC Tools press kit.
Everything a writer, directory editor or roundup author needs on one page: descriptions you can paste, facts you can check, a logo and screenshots you can use, and the person to email when something is wrong. No sign-up, no PR agency, no embargo.
Boilerplate
Three lengths. Copy whichever fits.
One line (78 characters). Free Manual J load calculator with real ZIP design temperatures. No account.
Short (under 160 characters). Free HVAC load calculator using the Manual J method. Heating and cooling BTU and tons from your ZIP code, with real design temperatures. No account.
Long. HVAC Load Calculator runs a whole-house Manual J block load in the browser. Enter a ZIP code, floor area, insulation level, window area and type, and duct location. It returns heating BTU, cooling BTU and nominal tons. The ZIP code resolves to published 99% winter and 1% summer design temperatures, and the result says how precisely the ZIP matched. It runs the same calculation engine as the iPhone and Android app, which adds room-by-room loads, equipment sizing and PDF reports, and works offline. It is an estimating aid based on Manual J methodology. It is not ACCA approved or certified.
Fast facts
The checkable parts.
- Who. Watson Consulting, a one-person software shop run by Mike Watson. No investors, no sales team.
- What. A free browser Manual J calculator at hvacloadcalculator.online, plus four field apps: HVAC Load Calculator (US, Manual J, iOS and Android), HVAC Load Calculator Canada (CSA F280-12, iOS), Static Pressure & Duct Check (Manual D, iOS) and A2L & EPA 608 Test Prep (EPA 608 and A2L exam practice plus R-454B and R-32 charging, iOS).
- Pricing. The web calculator, the browser tools and the guides are free with no account. The US app is free to download with a trial, then a subscription for unlimited room-by-room projects and PDF reports. Duct Tools is free. A2L & EPA 608 Test Prep is free with ads; an optional one-time $0.99 purchase removes them.
- Climate data. US: 99% heating and 1% cooling design dry-bulb values from the ENERGY STAR county-level reference, mapped to ZIP codes through the US Census ZCTA gazetteer. Canada: NBC 2020 Appendix C Table C-2 (BC Building Code 2024 in BC), 685 code locations and 1,651 forward sortation areas.
- Methods. ACCA Manual J 8th Edition methodology (US loads), CSA F280-12 methodology (Canada), ACCA Manual D methods (ducts), ASHRAE 34-2022 and UL 60335-2-40 (A2L charge limits). The tools are never described as approved or certified by ACCA, CSA Group, ASHRAE or UL.
- Parity. The browser calculator is extracted from the app’s source at build time. An automated test compares web and app results across 51 cases on every build and fails the build if they disagree. Details on the About page.
- Privacy. The calculators store nothing and need no email. See the privacy policy.
- Store listings. App Store ID 6758120488 (US), 6784766138 (Canada), 6786886923 (Duct Tools), 6760899340 (A2L & EPA 608 Test Prep). Google Play package
com.productparty.hvacloadcalc.
The angle
What is actually different.
- Real design temperatures, not a five-region dropdown. Most free load calculators ask you to pick a climate region. That can put the design condition 20°F off, and the load moves by roughly the same proportion. This one resolves the ZIP and tells you whether it matched a weather station, a reference city or only the three-digit prefix.
- It says what it will not do. The output states plainly that it is a whole-house block load, not a room-by-room design, and that duct design and Manual S equipment selection need the full calculation.
- Same math as the paid app. The free tool is not a simplified rewrite. It is the app’s engine with less of the output exposed, and a test proves it.
- Built by one person who answers the email. Several shipped changes started as a one-line note from a technician.
Assets
Logo and screenshots.
Free to use in coverage, listings and roundups. Please do not alter the icon’s colours or add effects.
Need a screenshot of the web calculator itself at a specific size, or a result for a specific ZIP code? Email and it will be sent the same day.
Maker
Mike Watson.
Mike Watson is a product lead and developer who builds field software for trades under the Watson Consulting name. The HVAC tools started from one complaint: the software that does load calculations properly is desktop software, priced for an office, and useless in a crawlspace. He writes about building software solo at Product Party, publishes code at github.com/productparty, and keeps a portfolio at mikewatson.us.
Available for: written Q&A, podcast interviews on load calculations and A2L refrigerants, and supplying numbers or charts for an article (for example, how much a 20°F design-temperature error moves a load).
Contact
One address, answered by the maker.
Press, listings, corrections and interview requests: mike@hvacloadcalculator.online. Put “press” in the subject line and it gets answered the same day.