Privacy

Privacy

Short version: what you type into the calculators stays in your browser. There are no accounts and no adverts, and the site sets no cookies.

What you enter

Room sizes, temperatures, humidity, U-values, prices and every other input are processed by JavaScript on your own device. They are not sent to Warm Window or to anyone else, and they are not saved once you leave the page. Copy and download buttons put the result on your clipboard or in a file on your device; nothing is uploaded.

What is stored on your device

Two preferences are saved in your browser's local storage: your light, dark or automatic theme (key warmwindow-theme) and your choice of metric or imperial units (key warmwindow-units). They never leave your device. Clearing your browser's site data removes them.

Analytics

The site is hosted on Cloudflare, which adds Cloudflare Web Analytics to the pages. It counts page views and gives broad figures such as country, browser and the page that sent the visit, without cookies and without tracking you across other websites. It never receives what you type into the calculators.

Like any web host, Cloudflare processes your IP address and request details to deliver the pages and protect the site from abuse.

Links to other sites

Pages link to the sources of their figures, to sister sites and to two free services, CleanTempMail and WebTraceCheck. Those sites have their own privacy policies, which apply once you follow a link.

Changes

If the site ever starts to handle data differently, this page will say so before the change takes effect. Last updated 30 October 2026.