Terms of Use

Acceptance of Terms

By accessing or using hvacloadcalc.org (the "Site"), you agree to be bound by these Terms of Use ("Terms"). If you do not agree to these Terms, do not access or use the Site.

These Terms apply to all visitors, users, and others who access the Site. The Terms are a binding agreement between you and hvacloadcalc.org governing your use of the Site. Use of specific features (calculators, articles, the email contact channel) is subject both to these Terms and to any additional terms or policies that may apply to those features (for example, the Privacy Policy and Disclaimer).

Continued use of the Site after these Terms are updated constitutes acceptance of the updated version. The "Last Reviewed" date at the bottom of this page indicates the version currently in effect.

Acceptable Use

You may use the Site for educational, research, and personal decision-making purposes. Permitted uses include:

• Reading and bookmarking articles, reference hubs, calculator pages, and methodology documentation.
• Sharing links to specific pages with colleagues, family, contractors, or in online discussions.
• Using the calculators to produce planning-grade output for evaluating contractor quotes, budgeting equipment purchases, and understanding magnitudes.
• Quoting brief excerpts (one or two paragraphs) of articles with attribution to hvacloadcalc.org and a link back to the source page, under fair use.
• Using calculator numeric outputs (the result for specific inputs) for personal or commercial purposes — these outputs are not copyrighted.
• Citing the Site in academic work, professional reports, or other publications, with standard attribution.

Prohibited Use

The following uses are not permitted. Engaging in any of them is a breach of these Terms and grounds for blocking access:

• Scraping the Site at industrial scale, or in a manner that disrupts service for other users.
• Republishing full articles, calculator pages, or substantial portions of the content without prior written permission.
• Using content to train commercial AI models without prior written permission. Personal AI-assisted reading (asking an LLM to summarize an article you are reading) is fine; ingesting the Site as part of a commercial training dataset is not.
• Reverse-engineering the calculator code in a way that violates the open-source spirit of the methodology while removing attribution.
• Misrepresenting Site content as the work of a credentialed professional engineer, ACCA-approved Manual J software, or licensed HVAC contractor.
• Using the Site for any unlawful purpose or in violation of any applicable law or regulation.
• Attempting to access non-public parts of the system (administrative routes, build artifacts, server infrastructure).
• Spamming the contact email at info@hvacloadcalc.org with promotional, malicious, or automated content.
• Interfering with security or operational features (rate-limiting, abuse detection, robots.txt directives) of the Site.

Intellectual Property

All content on hvacloadcalc.org — articles, methodology explanations, custom SVG diagrams, data tables, calculator code, and the overall Site design — is © 2026 hvacloadcalc.org unless explicitly attributed otherwise. Original content is protected by US and international copyright law.

Authoritative standards cited from third parties (ACCA, ASHRAE, AHRI, NEEP, NFRC, RESNET, DOE, EPA, IRS, EIA, IECC, ASTM, and similar organizations) remain the property of those organizations and are referenced under fair use for educational commentary, criticism, and review. The cited sources are identified inline via the SourceCite component and listed in the SOURCES section of each article.

Manufacturer references (Trane, Carrier, Lennox, Mitsubishi, Daikin, and similar) are nominative — used to identify the equipment or company being discussed. No endorsement, affiliation, or operational relationship is implied by these references.

The "hvacloadcalc.org" name and the Site design are not registered trademarks but are claimed as common-law trademarks of the Site. Use of the name or visually similar Site design in commercial contexts without permission is not permitted.

Calculator Output License

Calculator numeric outputs — the specific BTU/hr, ton, R-value, or load number that the calculator returns for your specific inputs — are not copyrighted and you may use them freely for any purpose, including commercial.

This carve-out exists because numeric outputs of mathematical calculations are generally not copyrightable under US law, and because the Site's mission is to make planning-grade numbers freely available. If you want to incorporate a planning-grade calculator output into a contractor quote evaluation, a permit-grade Manual J cross-check, a research project, or a downstream tool, you can do so without attribution.

The methodology explanation, the surrounding article content, the SVG diagrams, and the calculator source code remain copyrighted. If you want to build a derivative tool using the methodology, attribution and primary-source citation requirements apply to the methodology layer.

Third-Party Content and Links

The Site links to third-party resources (government publications, standards organization websites, manufacturer documentation, research lab publications, professional society resources) for educational purposes. hvacloadcalc.org is not responsible for the content, accuracy, or availability of any third-party site linked from the Site.

Third-party content embedded on the Site (Google AdSense advertisements, advertising creative served by Google's ad partners) is provided by those third parties and subject to their own terms. The Site does not endorse, control, or take responsibility for the specific ad creative shown on any page.

When a third-party source moves, updates, or changes its URL structure, the Site updates links on a quarterly review cycle. Broken or moved links can be reported to info@hvacloadcalc.org and are usually fixed within 14 days.

A link to a third-party source represents the editorial judgment that the cited information existed at the cited URL on the cited date; it does not represent any ongoing endorsement of the third-party site's overall content or business practices.

Advertising on the Site

The Site is funded by display advertising served through Google AdSense and its third-party advertising partners. Advertising is subject to the Google publisher policies, the Privacy Policy, and applicable advertising law. The Site itself does not control the specific advertisements shown to any individual user — selection is performed by Google and its partners based on context, user signals, and ad inventory.

Engaging with advertisements (clicking, viewing, completing a conversion) is governed by the third-party advertiser's terms, not by these Site Terms. The Site is not responsible for transactions or outcomes resulting from advertisement engagement.

If you encounter advertising that appears to violate Google's advertising policies (deceptive, malicious, or otherwise objectionable), report it to Google through the "Why this ad?" / AdChoices controls served with each ad, and optionally also to info@hvacloadcalc.org so the Site can flag the pattern for review.

Disclaimer of Warranty

THE SITE AND ALL CONTENT ON IT ARE PROVIDED "AS IS" AND "AS AVAILABLE" WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, NON-INFRINGEMENT, AND ACCURACY.

The Site does not guarantee that calculator output, article content, or referenced data will be accurate, complete, current, or suitable for any specific purpose. Planning-grade calculator output is explicitly NOT a substitute for permit-grade Manual J performed by a credentialed party using ACCA-approved software — see the Disclaimer for the full educational-scope disclosure.

The Site does not warrant uninterrupted availability. There is no service-level agreement, uptime commitment, or reliability guarantee. Hosting is provided by Vercel under its own terms; outages, latency, or platform changes are outside the Site's control.

The Site does not warrant that third-party content embedded on or linked from the Site is accurate, safe, or otherwise free of defect. Use of any third-party content is at your own risk.

Limitation of Liability

To the maximum extent permitted by applicable law, in no event shall hvacloadcalc.org, its author, or its operators be liable for any direct, indirect, incidental, consequential, special, exemplary, or punitive damages arising out of or in connection with the use of, or inability to use, the Site or its content.

This includes but is not limited to damages for:

• Equipment sizing errors leading to undersized or oversized HVAC installations.
• Installation outcomes including comfort issues, equipment failures, or ductwork problems.
• Energy costs higher or lower than predicted by Site calculators.
• Humidity, air quality, or comfort issues following installation.
• Safety incidents related to refrigerant handling, electrical work, or gas connections.
• Permit or rebate-program denials following submission of planning-grade calculator output where permit-grade software output was required.
• Warranty rejections by manufacturers or contractors.
• Lost profits, lost data, or business interruption of any kind.
• Any other consequence of relying on educational content from the Site.

The limitation of liability applies regardless of the legal theory under which damages are sought (contract, tort, negligence, strict liability, or otherwise) and regardless of whether the Site has been advised of the possibility of such damages.

Where applicable law prohibits the exclusion or limitation of certain damages (for example, certain consumer-protection laws limit warranty disclaimers), this section applies to the maximum extent permitted by law, and any non-excludable damages are limited to the lesser of (a) US $100 or (b) the amount you have paid to use the Site (which is zero, because the Site is free to use).

Indemnification

You agree to indemnify, defend, and hold harmless hvacloadcalc.org, its author, and its operators from and against any claims, damages, losses, liabilities, costs, and expenses (including reasonable attorneys' fees) arising out of or related to:

(a) Your use of the Site in violation of these Terms.

(b) Your violation of any applicable law or regulation in connection with your use of the Site.

(c) Your infringement of any third-party intellectual property, privacy, or other right.

(d) Any claim that your use of Site content (including calculator output) in your own work or decisions resulted in injury, financial loss, or other damage to a third party.

This indemnification obligation survives termination of your use of the Site.

Governing Law and Dispute Resolution

These Terms are governed by the laws of the United States, without regard to conflict-of-law principles. Any dispute arising out of or related to these Terms or your use of the Site shall be resolved in the appropriate US jurisdiction.

Where applicable consumer-protection law in your jurisdiction provides protections that cannot be waived by contract (for example, EU GDPR, California consumer law, UK consumer law, Brazilian LGPD), those protections apply notwithstanding these Terms, to the extent the protections cannot be waived.

Before filing a formal dispute, you are encouraged to email info@hvacloadcalc.org with subject "Dispute" and describe the issue. Most disputes can be resolved through informal communication, and the Site responds to substantive disputes within 30 days.

Severability and Entire Agreement

If any provision of these Terms is held to be invalid, illegal, or unenforceable by a court of competent jurisdiction, that provision shall be modified to the minimum extent necessary to make it enforceable, or severed from these Terms if modification is not possible. The remaining provisions shall continue in full force and effect.

These Terms, together with the Privacy Policy, the Disclaimer, and any additional policies linked from the Site, constitute the entire agreement between you and hvacloadcalc.org regarding your use of the Site. Any prior agreements, communications, or understandings on the same subject matter are superseded.

No waiver of any provision of these Terms shall be deemed a further or continuing waiver of that provision or any other provision. The Site's failure to enforce any right or provision of these Terms shall not be deemed a waiver of that right or provision.

Changes to These Terms

These Terms may be updated to reflect changes in Site practice, applicable law, or business model. Material changes are noted with an updated "Last Reviewed" date at the top of the page and a summary entry on the corrections log. Where a change materially reduces user rights, advance notice will be provided via the corrections log at least 30 days before the change takes effect.

By continuing to use the Site after these Terms are updated, you accept the updated version. If you do not accept the updated version, your remedy is to stop using the Site.

Contact

For any question about these Terms — interpretation, permission requests, disputes, or anything else — email info@hvacloadcalc.org. Substantive responses are provided within 30 days. There is no other channel for Terms-related communication.