The difference between declared and certified heat pump data
(What no one really explains…)
If you work with heat pumps, you’ve probably seen plenty of performance figures: efficiencies, capacities, noise levels, SCOPs. They’re everywhere - brochures, datasheets, ErP labels, websites. But here’s the part that often gets glossed over:
Not all performance data is created equal.
Across Europe, there are several well-known heat pump certification schemes, including Eurovent Certified Performance, NF, KEYMARK and MCS. Yet with so many technologies, brands and labels on the market, it’s not always obvious what sits behind the numbers, or why some products are certified under certain schemes, while others aren’t certified at all.
In this article we pull back the curtain and talk about what’s really going on behind heat pump performance data and why the numbers only tell half the story…
Three ways to measure performance data
When you strip it back, there are three main ways heat pump performance data is generated. They may look similar on paper, but in practice, they’re very different.
1. Self-declared data: “Trust us”
Self-declared data is exactly what it sounds like. The manufacturer tests the product (usually in-house) and declares the results themselves.
Why do manufacturers choose this route?
Because it’s faster, flexible and cost-effective. They control which products are tested, how they’re tested, and which results are published. There’s no additional third-party cost, which can help keep product prices down.
But here’s the catch. While regulations like Ecodesign require evidence to back up declarations, the depth and quality of that evidence can vary widely. Heat pumps can be tested according to different norms and regulations – there is no set criteria that manufacturers must follow. Additionally, even if manufacturers did measure the same characteristics, their in-house test environment, equipment, calibration, tolerances or methodologies can differ. When testing conditions and criteria are different, performance figures cannot be reliably compared between units. The final, crucial point, is that when companies choose which units to test, which conditions to test to and which results to publish, there’s always a risk of bias in the results, whether intentional or not.
In short: While self-declared data can be accurate, with no third-party verification or standardised testing procedure, HVAC professionals, decision makers and end users need to trust the manufacturer’s testing process and hope the data provided allows for meaningful comparison with other products.
2. Independent laboratory data: “Someone else checked it”
The next step up is testing carried out by an independent laboratory.
What’s better about this?
Third-party labs work to recognised standards and controlled conditions, which adds objectivity and credibility compared with in-house testing alone.
But there are still limitations. Lab testing typically covers manufacturer selected units, tested under specific conditions requested by the manufacturer. Again, as heat pumps can be tested according to different norms and regulations, there is no set criteria that laboratories must follow. Plus, there’s no guarantee the tested unit reflects everyday production, and there’s usually no follow-up testing once the initial results are published.
On top of that, not all laboratories are accredited to ISO 17025 - the international benchmark for testing competence.
In short: Independent lab testing is undoubtably a step forward in achieving reliable performance data. However, lab testing is usually a snapshot of product performance – it tells us how that particular unit performs under specific conditions at one point in time. It does not provide a full picture of product performance, or guarantee that data is representative of production line units or directly comparable with other models.
3. Certified data: “Let’s really put it to the test”
This is where certification changes the game. Certification goes far beyond a single test. Yes, it still relies on independent, ISO 17025-accredited laboratories, but that’s just the starting point.
Certified performance data is assessed against publicly available Technical Certification Rules, and the process can include:
- Independent, random, product selection (tested units not chosen by the manufacturer)
- Testing under multiple operating conditions to mimic real life operation
- Verification of technical documentation to ensure all touch points (brochures, websites, technical specs etc) include accurate, certified data
- Factory audits to ensure production line quality
- Ongoing surveillance after initial certification to ensure products continue to comply with declared values.
In schemes run by Eurovent Certification, manufacturers don’t have any direct contact with the test laboratory. That separation reduces bias and ensures the process stays objective from start to finish.
What’s better about this?
Its fully independent, impartial and follows standardised testing protocols. Products must pass all checkpoints to receive certification. All products within a programme are treated equally and undergo exactly the same certification and surveillance procedure. Not only does this provide transparent, impartial performance data, but it also provides data which is up-to-date and easily compared like-for-like across other models and brands within the certification programme.
In short: Certification guarantees performance and builds trust in products. Only certification provides a common basis for product comparison, as all heat pumps are tested in equal conditions. Certification’s comprehensive evaluation process provides accurate data which is designed to reflect real-world use - not just ideal lab conditions.
| In-house laboratory testing | Independent laboratory testing | Eurovent heat pump Certification programmes | |
|---|---|---|---|
| Independent from manufacturer | No | Yes | Yes |
| Testing process outside of manufacturer control | No | Yes | Yes |
| Standardised testing procedure | No | Yes | Yes |
| Laboratories must be assessed according to ISO 17025 standard | No | Not always | Yes |
| Manufacturer and laboratory contact limited | No | No | Yes |
| Products selected independently | No | No | Yes |
| Third party factory audits to ensure production line quality | No | No | Yes |
| Free to access product database containing standardised data | No | No | Yes |
| Ongoing independent surveillance process | No | No | Yes |
Table 1: Summary of certification vs laboratory testing vs in-house evaluation
Why this difference really matters
This isn’t just a technical debate. In essence, the difference matters because each level of validation – from self-declaration up to certification – builds trust in performance figures. Data on efficiencies, capacities and noise levels is critical for decision-makers and designers who need highly accurate data to reliably compare products, ensure regulatory compliance, and minimise risk of system underperformance. Transparent performance data impacts on operation too, as it’s essential for accurately predicting long-term energy use and costs – something dear to the heart of every energy bill payer.
The bottom line
Here’s the secret that’s often left unsaid:
Performance numbers only tell half the story. How those numbers are produced matters just as much.
Self-declared data offers flexibility and low cost for the manufacturer, but those using the figures must trust that the data is accurate and unbiased.
Independent laboratory data adds credibility and objectivity, but remains a snapshot in time, with no guarantee the figures are up-to-date, or the tested unit reflects everyday production.
Certified data, while more demanding and costly for the manufacturer, provides the highest level of confidence - because it’s standardised, unbiased, independently verified, continuously checked, and fully transparent.
In a market where performance claims directly influence investment decisions, energy targets and regulatory compliance, certification isn’t just a nice-to-have. It’s the difference between taking data at face value and truly being able to rely on it. And once you know that you start looking at heat pump performance data very differently.
View and compare certified heat pumps
View our certification programmes
Join our LinkedIn community!
Heat pump certification: a direct response to unreliable data
Rooftop heat pump collaboration meets new heights
Certify Your Products
