Terms of Service

Last updated: October 2026

These terms apply to Supply & Return, a free website of HVAC calculators for room cooling loads, heat loss, airflow, duct sizing, SEER2 savings and ventilation. By using the site you accept these terms, our Privacy Policy and our Disclaimer. If you do not accept them, please do not use the site.

Using the Calculators

You may use the tools and guides free of charge, without an account, for personal, educational and professional purposes, including checking quotes and preparing estimates. Results depend on the values you enter and the methods stated on each page. You are responsible for checking that a result suits your building, climate, equipment and local code before acting on it.

No Professional Advice

The site provides general technical information. It is not engineering, design or installation advice, and it does not replace a load calculation, equipment selection or duct design by a qualified professional. Nothing on the site authorises you to carry out gas, electrical or refrigerant work, which must be performed by licensed technicians.

Quotes and Purchases

If you use a result to compare contractors' quotes or to choose equipment, the decision is yours. Contractors may have good reasons to differ from our estimates, such as a full room-by-room calculation or information about the house that the tools do not include. Ask them to show their calculation.

Acceptable Use

Do not attempt to disrupt the site, scrape it at a rate that affects other users, introduce malicious code or use it for any unlawful purpose.

Intellectual Property

The text, graphics and code of the site belong to Supply & Return or its licensors. You may quote short passages with a link back and use results in your own estimates and reports. Standards and programme names belong to their owners and are used only to describe the subject.

Availability and Changes

We aim to keep the site available and correct but do not guarantee uninterrupted access. We may change, add or remove tools and content at any time.

Limitation of Liability

The site is provided "as is" without warranties of any kind. To the extent permitted by law, we are not liable for any loss arising from use of the site, including equipment purchases, installation costs, energy bills, property damage or injury based on the calculators. Nothing in these terms limits liability that cannot be limited by law.

Governing Law and Contact

These terms are governed by the laws applicable where the site operator is established. Questions can be sent to logan.luo@adsnova.cn.