What we store, who processes it, how long we keep it, and how to have it deleted. Last updated 15 August 2026.
HVAC Builder is an engineering tool. Most of what it holds is equipment data you typed — coil geometries, weather years, system graphs. This page is about the rest.
| Data | Why we have it |
|---|---|
| Account identifier — the subject id issued by our sign-in provider, plus your plan, token balance and usage counters | To attach your work to your account and meter what your plan includes |
| Your designs — saved systems, buildings, simulation runs, weather datasets you import | They are the product; they are yours |
| Supplier profile and listings, if you register as a supplier — company, contact email, territory reps, published components and systems, product links and images | Published listings are public by design; that is what a directory is |
| Quote requests (RFQ) — name, email, company and message of whoever asks a supplier for a quote, plus the design referenced | To pass the enquiry to the supplier it was addressed to |
| Credentials — SHA-256 hashes of API keys and OAuth tokens (never the values), registered OAuth clients, and your own AI provider key if you store one | To authenticate programmatic access you asked for |
| Billing identifiers — the customer and subscription ids issued by our payment processor | To reconcile a subscription with an account. We never see or store card details. |
We do not run advertising or analytics trackers. There is no third-party analytics script on any page of this site, and no advertising cookies. The only cookies in play are the ones our sign-in provider sets to keep you signed in.
To run the product you asked for: solving and simulating your designs, storing them under your account, metering your plan, billing your subscription, publishing the listings you choose to publish, and delivering quote requests to the supplier they name. Nothing else. We do not sell personal data, and we do not use your designs to train AI models.
These are the only third parties our servers talk to on your behalf:
| Processor | What reaches them |
|---|---|
| Clerk — authentication | Your sign-in identity. They hold your email and password/social identity; we hold only the identifier they issue. |
| Stripe — payments | Your payment details, which go to Stripe directly and never through our servers. |
| Resend — email delivery | The contents of a quote request, emailed to the supplier it was sent to. |
| Anthropic — the AI assistant and the MCP connector | Only when you use them: the messages you send and the parts of the design the assistant reads. If you store your own AI provider key, the traffic is billed to your account instead of ours. |
| Hetzner — hosting (Germany) | Everything above, at rest. The application and its database run on servers in the EU. |
Outbound weather data comes from PVGIS (European Commission, JRC). No personal data is sent to obtain it.
Saved systems, buildings and supplier listings are kept until you delete them or close your account. Simulation runs are pruned automatically to your plan's limit, oldest first. Quote requests are kept per supplier up to a fixed retention cap (currently 500), after which the oldest are deleted. OAuth access tokens expire after 8 hours and refresh tokens after 90 days; revoking a connection deletes them immediately. An API key exists until you revoke it. Deleting an item in the app deletes the record, not a flag on it.
In the app you can delete any saved system, building or run, revoke any API key, and disconnect any connected app — each takes effect immediately. To close your account and have everything associated with it deleted, or to request a copy of it, email privacy@hvacbuilder.app and we will action it. If you are in the EU or UK, the GDPR rights of access, rectification, erasure, restriction, portability and objection apply, and you may complain to your local supervisory authority.
Everything is served over HTTPS. API keys and OAuth tokens are stored only as SHA-256 hashes — a database copy would not yield a usable credential. Administrative actions require an interactive signed-in session, never a long-lived key. Access to another account's data is refused by owner scoping, not by hiding links.
HVAC Builder is a professional engineering tool. It is not directed at children and we do not knowingly collect data from them.
If this policy changes materially we will update the date above and, for changes that affect how your data is used, tell account holders by email. Questions: privacy@hvacbuilder.app.