HeatAlgo Terms of Service - version of September 28, 2026

§1 The Provider and general provisions

These terms govern the use of the HeatAlgo service, operated by Cratun Sp. z o.o., registered office at Niekłonice 49E, 76-024 Niekłonice, entered in the register of entrepreneurs of the National Court Register by the District Court in Koszalin, 9th Commercial Division of the National Court Register under KRS number 0000971816, tax ID (NIP): 4990690625, REGON: 522021073, share capital: PLN 168,000 (the "Provider").

Contact: e-mail [email protected], telephone +48 533 203 816, postal address: Niekłonice 49E, 76-024 Niekłonice. The same e-mail address is the single point of contact for Users and for the authorities of the Member States, the European Commission and the European Board for Digital Services within the meaning of Articles 11 and 12 of the Digital Services Act (Regulation (EU) 2022/2065). We correspond in Polish or English.

These terms are made available free of charge at heatalgo.com/en/terms, before the agreement is concluded and at any time, in a form that allows them to be downloaded, saved and printed. The Polish version (Regulamin) is authoritative; this English version is a translation provided for convenience.

§2 Definitions

Service - the HeatAlgo web application available at heatalgo.app, comprising the following modules: heat load calculation, heat pump sizing, underfloor heating design and heat recovery ventilation design, together with the Algo AI assistant, My library and the client form. The heatalgo.com website is the Service's information site.

User - a natural person with full legal capacity, a legal person or an organisational unit with legal capacity granted by statute, who has created an Account.

Consumer - a User who is a natural person entering into an agreement with the Provider not directly related to their business or professional activity.

Sole trader with consumer rights - a natural person entering into an agreement directly related to their business activity where the content of the agreement shows it is not of a professional nature for them (Art. 7aa of the Polish Consumer Rights Act of 30 May 2014). The provisions of these terms concerning Consumers as regards the right of withdrawal (§10), conformity of the service (§13) and changes to the Service (§14) apply to them accordingly. Such a person may, at the latest when concluding the agreement, declare by writing to the address in §1 that the agreement is or is not of a professional nature for them; concluding the agreement does not depend on that declaration.

Account - the User's individual account in the Service. An Account is for one person: only one person may use its login details.

Project - a single piece of work carried on by the User in the Service, comprising building data and calculation results across all of the Service's modules.

Free Plan - the free scope of the Service described in §5.

Report - a one-time, paid unlock of one Project, described in §7.

Subscription (Installer Plan) - the paid, renewing service described in §8.

Algo AI - the Service's assistant based on artificial intelligence, described in §11.

AI Limit - the monthly pool of tokens (units of text processed by an AI model) used by conversations with Algo AI and project reviews, described in §11.

User Content - data, files and texts the User enters, uploads or shares in the Service, including their clients' data.

User's Client - a person whose data the User enters in the Service or to whom the User sends the client form.

Price List - the current prices and scope of the plans, published at heatalgo.com/en/pricing.

§3 Technical requirements

To use the Service you need: a device with internet access, a web browser no older than a Chrome-98-compatible Chrome, Edge or Opera, Firefox 95 or Safari 15.4, with JavaScript and browser storage enabled, an active e-mail address and - to open reports - a PDF reader.

The Service runs in the browser and requires no software installation.

Using the internet carries typical risks, such as malware or attempts to take over login details. The Provider uses an encrypted connection and optional two-step verification; the User protects their login details and device.

§4 Conclusion and termination of the agreement

An Account is created by entering an e-mail address and password or by signing in with a Google account, where that method is available. Registration with an e-mail address requires confirming it. The agreement for keeping an Account is concluded when registration is completed, which includes accepting these terms. Consent to receive offers by e-mail is separate and voluntary.

The agreement for keeping an Account is free of charge and concluded for an indefinite period. Agreements for a Report and a Subscription are concluded in the Service at purchase, on the terms of §6-§8.

The User may terminate the agreement for keeping an Account at any time, without giving reasons, by writing to the address in §1. Termination takes effect on delivery, and the Account is deleted as described in the Privacy Policy. Termination does not release the User from fees for a Subscription period that has already started, without prejudice to the rights of a Consumer.

The Provider may terminate the agreement for keeping an Account with 30 days' notice for important reasons: the Service being discontinued or a change in the law that prevents it from being provided. For good cause, namely a gross or persistent breach of these terms (in particular an attempt to breach the Service's security, sharing an Account with other people or supplying illegal content), the Provider may suspend the Account or terminate the agreement with immediate effect. In every case the Provider gives the User a statement of reasons on a durable medium (§16).

Before an Account is deleted, the User may obtain their data as described in §18.

§5 Free Plan

The Free Plan is available to every Account, with no time limit and without entering payment card details. On the Free Plan the User creates any number of Projects and enters data in all modules.

The Free Plan has a limited scope: the full calculation result is shown for part of a Project, while method details, comparisons, the PDF report and the printable floor plan, drawing all storeys, and some Algo AI and My library features are available after unlocking the Project or with a Subscription. The current scope of the Free Plan, including the number of rooms with a full result, free AI readings and My library entries, is set out in the Price List.

§6 Paid services, prices and the seller

The paid services are the Report (§7) and the Subscription (§8). Prices are set out in the Price List; they are the prices the buyer pays, VAT included. The price shown in the Service before payment is the final price of that transaction.

Purchases in the Service are processed by Stripe through its Managed Payments service. The seller in that transaction is the Stripe group company named on the payment page and on the invoice, not the Provider: it takes the payment, issues the invoice and handles payment refunds, under its own terms presented during payment. The Provider remains party to the agreement for the provision of the service - it keeps the Account, provides the modules and generates documents - and that is the agreement these terms govern. Payment methods are shown on the payment page. The Provider does not receive payment card details.

The Provider may also conclude an individually negotiated agreement with a company (heatalgo.com/en/for-companies). In that case it sells in its own name and issues a VAT invoice, and these terms apply to matters that agreement does not govern.

§7 Report

Buying a Report gives the User one report to use. A report to use does not expire and does not renew automatically.

A report to use is used up when it unlocks a Project: on the first download of the Project's full document, or on accepting the result of a paid AI reading in that Project, which the Service announces before the reading starts. The unlock covers all modules of that Project (heat load calculation, heat pump sizing, underfloor heating, heat recovery ventilation) and applies to one job.

From the first report download the User has 7 days to make corrections and download further versions of that Project's report; a separate 7-day period runs from the first download of the printable floor plan. After it ends, downloading again requires another Report or an active Subscription. Downloaded files remain with the User, and the Project and the on-screen results stay on the Account with no time limit.

§8 Subscription

The Subscription is paid in advance for the billing period chosen at purchase: one month, six months or one year. For its duration it lifts the limits on downloading reports and floor plans across all of the User's Projects, raises the AI Limit (§11) and lifts the limit on My library entries.

The Subscription renews automatically for another period of the same length unless the User cancels it before the current period ends. It can be cancelled at any time in the Account settings (Billing) or by writing to the address in §1. 14 days before a six-month or annual Subscription renews, the Provider sends a reminder by e-mail.

Cancellation takes effect at the end of the paid period: until then the User keeps full access, and the Provider does not refund part of the fee for unused time - without prejudice to the right of withdrawal (§10) and the rights under §13.

When the Subscription ends, the Account returns to the Free Plan. Projects, calculations and all My library entries stay on the Account; new entries cannot be added beyond the Free Plan limit. Downloaded documents remain with the User.

The Provider notifies the User by e-mail of a change in the Subscription price at least 30 days before the start of the billing period from which the new price is to apply. A User who does not accept the new price may cancel the Subscription before that day at no cost; the current period is charged at the previous price.

§9 Promotions and discount codes

The Provider may offer discounts: discount codes, offers granted to an Account in the Service (for example for completing the Account setup) and offers sent by e-mail to people who agreed to receive them. With each offer we state the discount, the plans it applies to and its expiry; those conditions take precedence over the general rules in this paragraph.

One discount can be applied to one purchase. Discounts cannot be combined, cannot be exchanged for money and - unless the offer says otherwise - apply to the first payment for the plan concerned. With every price reduction we also state the plan's lowest price in the 30 days before the reduction.

§10 Right of withdrawal

A Consumer who has concluded a distance agreement may withdraw from it within 14 days of its conclusion, without giving reasons and at no cost, subject to the exceptions below. Sending the statement before the deadline is sufficient. The statement may be sent by e-mail to the address in §1, by post, or on the form set out in the Annex; the Provider confirms receipt by e-mail. Where the seller is a Stripe group company (§6), the Provider forwards the statement to it, and the Consumer may also send it to the seller directly.

The Report is digital content. The right to withdraw from the Report agreement does not apply if, before paying, the Consumer ticked a separate statement in the Service asking for the report to be made available before the withdrawal period ends and acknowledging that they lose the right of withdrawal once it is made available, and the Provider confirmed that statement by e-mail (Art. 38(1)(13) of the Polish Consumer Rights Act). Until the report is used (§7), the Consumer may withdraw.

The Subscription is a digital service. The Consumer may withdraw from it within 14 days even if the Subscription is already running. If, before paying, they asked in the Service for it to start before the withdrawal period ends, they pay for the period from the start until withdrawal, in proportion to the price of the billing period (Art. 35 of the Polish Consumer Rights Act), and the rest of the price is refunded.

The refund is made without undue delay and no later than 14 days after the statement of withdrawal is received, using the same means of payment the Consumer used, unless they expressly agreed to another means that costs them nothing. The refund is made by the seller named in §6.

§11 Algo AI

Algo AI is an artificial intelligence system: it answers questions about a Project, reviews calculations, reads data from building documents and floor plans and - on the User's express instruction - makes changes in Projects and in My library. It uses AI models from third-party providers, which the Provider selects for the task and may replace.

Algo AI can make mistakes, including about regulations and values read from documents. Values read from documents are a proposal: they enter the Project once the User accepts them, including where the User chose the mode in which the Service accepts them on the User's behalf. The Service shows changes made by Algo AI in the conversation and lets the User undo them within the period stated there. Heat load calculations are always performed by the Service's algorithm, not by an AI model.

The monthly AI Limit is 200,000 tokens on the Free Plan, 500,000 tokens on an Account that has bought a Report, and 1,500,000 tokens with a Subscription. The pool renews on the first day of each calendar month (Polish time) and does not carry over. How many conversations fit in the pool depends on their length and the model used; usage is shown in the Service. Reading data from building documents and floor plans does not use the AI Limit but the rules in §5 and §7, which the Service states before the reading starts.

How Algo AI processes data is described in the Privacy Policy.

§12 Nature of the service and liability

The Service is a calculation and design tool. It performs heat load calculations in accordance with PN-EN 12831-1, PN-EN ISO 6946 and PN-EN ISO 13370 (the Polish adoptions of EN 12831-1, EN ISO 6946 and EN ISO 13370), within the scope described in the Service, based on data entered by the User. Results depend on that data, and the Service supports, but does not replace, the knowledge and judgement of the person designing or installing the system.

Towards Users who are neither Consumers nor sole traders with consumer rights: the Provider is not liable for lost profits or for the consequences of design and installation decisions made on the basis of incomplete data or data that does not match the building, and its contractual liability is limited to the fees paid for the Service in the 12 months before the event that caused the damage. These limitations do not apply to damage caused intentionally or through gross negligence.

Towards Consumers and sole traders with consumer rights the Provider is liable under the general rules, and these terms do not exclude or limit their statutory rights.

The Provider takes care that the Service runs continuously but may suspend it temporarily for maintenance, updates or to fix a fault, announcing longer interruptions in the Service where possible.

§13 Conformity of the service with the agreement

The Provider is liable to the Consumer for the Service's conformity with the agreement under Chapter 5b of the Polish Consumer Rights Act: for the Subscription and the Free Plan throughout the period of supply, and for the Report for a lack of conformity existing when it is supplied and becoming apparent within two years. The Provider supplies the updates, including security updates, needed to keep the Service in conformity.

If the Service does not conform with the agreement, the Consumer may demand that it be brought into conformity. Where that is impossible, would require excessive costs, has not happened within a reasonable time, or the lack of conformity is significant, the Consumer may declare a price reduction or - where the lack of conformity is not minor - withdraw from the agreement. The refund is made within 14 days of receiving the statement.

§14 Changes to the Service

The Provider develops the Service and may change its features, appearance and operation, including in ways not needed to keep it in conformity, for the following valid reasons: a change in the law or in the standards the calculations rely on; the security of the Service and of data; a change in or withdrawal of a third-party provider's service, including an AI model; technical development and adding new features; removing features Users do not use.

A change costs the Consumer nothing. If a change materially and negatively affects access to or use of the Service, the Provider announces it in advance on a durable medium, and the Consumer may, within 30 days of the change or of that announcement, terminate the agreement at no cost and receive a refund of the price for the period after termination. Changes do not affect a Report already supplied.

§15 Complaints

Complaints can be sent by e-mail to [email protected] or by post to the address in §1. A complaint should include the Account's e-mail address, a description of the problem and, where possible, the Project name, the date of the event and how you would like it resolved. Missing details do not mean the complaint will not be considered.

The Provider replies to a complaint within 14 days of receiving it, by e-mail or on another durable medium. If a Consumer filed the complaint and the Provider does not reply within that time, the complaint is deemed accepted.

A complaint about a decision described in §16 is filed the same way.

§16 User Content and its moderation

The User may not supply illegal content, including content infringing third-party rights, data of people whose data they have no right to process, or malware, and may not use the Service contrary to its purpose, in particular by collecting the Service's data automatically or sharing the Account with other people.

Anyone may report content in the Service they consider illegal to [email protected]. The notice should include an explanation of why the content is illegal, its exact location (for example the client form's address), the notifier's name and e-mail address - unless it concerns offences against children - and a statement that the notice is made in good faith. The Provider confirms receipt of the notice and informs the notifier of its decision.

Notices and breaches are reviewed by a person; the Provider does not use automated content moderation. If the Provider removes content, disables access to it, or suspends or closes an Account, it gives the User a statement of reasons on a durable medium, stating the basis for the decision and the options of filing a complaint (§15) and going to court. The Provider notifies the competent authorities of a suspected offence threatening a person's life or safety.

§17 Personal data and data processing

How the Provider processes the data of Users, for which it is the controller, is described in the Privacy Policy (heatalgo.com/en/privacy).

The User entrusts the Provider with processing the data of the User's Clients that the User enters in the Service or that Clients submit through the client form; the User is its controller and ensures a legal basis for processing it and that Clients are informed. This paragraph is a data processing agreement within the meaning of Article 28 GDPR. The subject matter of processing is Clients' identification and contact data, the building's address, building data, and answers and files from the client form; its purpose is providing the Service, including through Algo AI on the User's instruction; its duration is the period for which the Account is kept.

The Provider processes that data only on the User's documented instructions, which consist of using the Service's features; ensures that persons authorised to process it have committed to confidentiality; applies the security measures of Article 32 GDPR; assists the User in fulfilling data subjects' rights and the obligations of Articles 32-36 GDPR; notifies the User of a personal data breach concerning that data without undue delay and no later than 48 hours after becoming aware of it; and makes available the information needed to demonstrate compliance with these obligations and allows audits at a date agreed in advance.

The User gives general authorisation for the Provider to engage the sub-processors listed in the Privacy Policy (section 5). The Provider announces an intended addition or replacement of a sub-processor by updating the Privacy Policy at least 14 days in advance; a User who objects may terminate the agreement before the change takes effect. Sub-processors are bound by the same data protection obligations.

When the agreement ends, the Provider deletes the data of the User's Clients as described in the Privacy Policy, after allowing it to be obtained (§18), unless the law requires it to be retained.

§18 Obtaining your data and switching provider

Downloaded reports and floor plans are available in the Service under §7 and §8. Regardless of the plan, on request sent to the address in §1 the Provider gives the User, free of charge and in a commonly used machine-readable format (JSON, and files in the format in which they were uploaded), the data entered by the User and the calculation results of their Projects, My library entries, uploaded floor plans and client form answers. The Service's code and algorithms are not part of the export.

A User who wants to move their data to another provider or to their own infrastructure may terminate the agreement for that purpose at any time (§4, §8). The Provider hands over the data within 30 days of the request, continues to provide the service within the purchased plan during that time, and the data remains available for at least 30 days after the handover; it is then deleted as described in the Privacy Policy. The Provider charges no fees for switching provider or for exporting data.

§19 Intellectual property

The Service, including its code, interface, algorithms, catalogues and materials, belongs to the Provider or its licensors. For the duration of the agreement the User may use the Service in accordance with these terms; they may not copy, decompile or reverse-engineer it except where the law permits.

User Content remains the User's property. The User grants the Provider a non-exclusive, royalty-free licence to store and process User Content to the extent needed to provide the services, for the duration of the agreement. The User may use reports, designs and files generated in the Service without restriction, including sharing them with their clients.

§20 Out-of-court dispute resolution

A Consumer may use out-of-court complaint and redress procedures, in particular by asking a municipal or district consumer ombudsman for help, applying to the provincial Trade Inspection inspectorate for mediation, or applying to a body authorised to resolve consumer disputes out of court. The list of such bodies is kept by the President of the Office of Competition and Consumer Protection (uokik.gov.pl). The Provider has not committed in advance to take part in such proceedings; after considering a complaint it states whether it agrees to them.

§21 Governing law and courts

Agreements with the Provider are governed by Polish law. This choice of law does not deprive a Consumer of the protection afforded by the mandatory provisions of the country of their habitual residence.

Disputes with Users who are neither Consumers nor sole traders with consumer rights are resolved by the court competent for the Provider's registered office. Disputes with Consumers are resolved by the court competent under the general rules.

The choice of law and court concerns the agreement with the Provider; it does not determine the law governing the sale agreement concluded with the seller named in §6.

§22 Changes to these terms and final provisions

The Provider may change these terms for important reasons: a change in the law or in its interpretation by courts or authorities, a change in the scope or operation of the Service (§14), a change in prices or plans, a change of the seller or of providers the Service depends on, and the need to remove ambiguities. Users are told of a change by e-mail at least 14 days before it takes effect, and the new version is published at heatalgo.com/regulamin together with its effective date. A User who does not accept the change may terminate the agreement before that day at no cost. A change in the Subscription price follows §8.

Agreements concluded before a change takes effect are governed by the previous version of these terms until the day the change takes effect. Previous versions of these terms are available on heatalgo.com.

Annex - model withdrawal form

(complete and return this form only if you wish to withdraw from the agreement)

To: Cratun Sp. z o.o., Niekłonice 49E, 76-024 Niekłonice, e-mail: [email protected]

I/We(*) hereby give notice that I/We(*) withdraw from my/our(*) agreement for the provision of the following service / the supply of the following digital content(*): …

Concluded on: … / Name of consumer(s): … / Account e-mail address: … / Address of consumer(s): …

Signature of consumer(s) (only if this form is notified on paper): … / Date: …

(*) Delete as appropriate.