Effective date: July 14, 2026
This Privacy Policy explains what information DuctMath (“we”, “our”, or “this site”, accessible at ductmath.com) collects, how it is used, and the choices you have. DuctMath is a free collection of HVAC calculators and reference tools. Using the calculators does not require an account, and the calculations themselves run in your browser.
Information we collect
Information you provide
If you contact us through the contact form or by email, we receive the information you choose to send — typically your name, email address, and message. We use it only to respond to you and to improve the tools, and we do not sell it or add you to marketing lists.
Information collected automatically
Like most websites, we and our service providers may automatically collect standard technical data when you visit: IP address, browser type, device type, pages visited, referring pages, and timestamps. This data is used in aggregate to understand which tools are useful, keep the site fast, and protect it from abuse.
Cookies
Cookies are small files stored by your browser. This site uses cookies and similar technologies for basic site functionality, aggregate analytics, and — once advertising is enabled — for serving and measuring ads. You can control or delete cookies through your browser settings; the calculators will continue to work with cookies disabled.
Advertising (Google AdSense)
We use, or intend to use, Google AdSense to display advertising on this site. You should know the following:
- Third-party vendors, including Google, use cookies to serve ads based on your prior visits to this website and other websites.
- Google’s use of advertising cookies enables it and its partners to serve ads to you based on your visits to this site and/or other sites on the Internet.
- You may opt out of personalized advertising by visiting Google Ads Settings. You can also opt out of some third-party vendors’ use of cookies for personalized advertising at www.aboutads.info.
- Depending on your region, you may be shown a consent message that lets you choose how your data is used for advertising before any advertising cookies are set.
Analytics
We may use privacy-respecting analytics tools (such as Google Analytics) to understand aggregate site usage — which pages are visited and how the site performs. This data is not used to identify individual visitors. Where analytics cookies are used, they are covered by the consent choices described above.
What we do not collect
The numbers you type into the calculators — model numbers, pressures, temperatures, room dimensions — are processed in your browser to produce your result. We do not require or store personal identity information to use any tool on this site.
How information is shared
We do not sell personal information. Technical and usage data may be processed by service providers who help operate the site (hosting, analytics, advertising) under their own privacy commitments. We may disclose information if required by law or to protect the site and its users.
Your rights
Depending on where you live (including the EU/EEA, UK, and California), you may have rights to access, correct, or delete personal information we hold about you, and to object to or restrict certain processing. Because we hold very little personal data — typically only contact-form messages — the fastest way to exercise these rights is to email us, and we will act on legitimate requests within a reasonable time.
Children’s privacy
This site is intended for a general audience of adults working with HVAC equipment and is not directed at children under 13. We do not knowingly collect personal information from children under 13. If you believe a child has provided us personal information, contact us and we will delete it.
Data security and retention
We take reasonable measures to protect the information we hold. Contact messages are kept only as long as needed to handle the inquiry and improve the tools, then deleted.
External links
Tool pages may link to external references (such as manufacturer directories). Those sites have their own privacy policies, which we do not control.
Changes to this policy
If this policy changes, the updated version will be posted on this page with a new effective date.
Contact
Questions about this policy: contact@ductmath.com, or use the contact page.