As more buildings across Europe undergo energy-focused refurbishments, the spotlight is turning toward the long-term performance of low-carbon heating systems. For Swiss engineer Ruedi Kriesi, this isn’t just a technical curiosity, it’s a national compliance challenge.
Over the last decade, Ruedi has deployed over 300 Tinytag data loggers across 150 residential sites, using temperature monitoring to assess the performance and longevity of earth probe heat pump systems. His work helps homeowners and contractors validate system design, prove energy efficiency compliance, and ensure buildings meet performance expectations years after installation.
Monitoring Beyond Commissioning
Ground-source heat pumps are a popular low-carbon choice in Swiss property refurbishments due to their low running costs and reduced emissions. But according to Ruedi, the long-term success of these systems often depends on what happens after commissioning.
“After around 20 years, many probes begin to fail,” he explains. “It’s not the heat pump, but the ground source. If you take heat from the ground but don’t replenish it in summer, the ground doesn’t recover. Probes cool and eventually freeze.”
This deterioration compromises performance and breaches local building codes but without data, it’s difficult to detect. That’s where Tinytag Ultra 2 temperature loggers come in.
Simple Tools, Powerful Insight
Ruedi’s approach is deliberately straightforward. Loggers are deployed during the winter heating season, usually installed in the mechanical room or near the heat pump. Once the season is over, users post them back, and he provides a full analysis of system performance.
“No Wi-Fi, no cloud platform, just independent data,” says Ruedi. “It’s a low-cost, low-tech way to gain high-impact insight, especially in retrofitted homes.”
This approach supports:
- Early detection of underperformance or system imbalance
- Verification of compliance with national energy standards
- Regeneration planning for earth probes
- Evidence-based reporting for building owners and retrofit contractors
The loggers are easy to use, highly accurate, and require no permanent installation, making them ideal for seasonal monitoring or post-refurbishment audits.
From Temperature to Energy: A Natural Next Step
While Ruedi’s work centres on temperature logging, the logical next step in retrofit verification is power monitoring. For engineers and building professionals looking to track system efficiency and consumption patterns alongside thermal performance, pairing the Ultra 2 with the Tinytag Energy Logger creates a comprehensive data set.
The Tinytag Energy Logger allows for real-time monitoring of electricity use, capturing energy drawn by heat pumps and other connected systems. Used together, both devices can offer a clear picture of how much energy is consumed, where it goes, and how efficiently it’s used. Essential insight for smart building strategies, compliance audits, and client transparency.
This powerful pairing is particularly relevant where integrated energy and environmental monitoring is critical to informed decision-making in retrofit and renovation projects.
Data That Shapes Regulation
Ruedi’s long-term monitoring efforts have contributed to updates in Swiss national guidance around earth probe systems. His findings helped influence changes in borehole design recommendations, especially around seasonal regeneration and system lifespan.
Where regulations once assumed earth probes could run indefinitely, Tinytag data revealed gradual temperature degradation over time, a challenge invisible without long-term logging.
“The drop happens slowly. If you only check performance one or two years in, you miss the trend entirely,” says Ruedi.
Practical, Scalable, Proven
With mounting pressure to decarbonise existing housing stock, the need to validate and future-proof building systems is greater than ever. Tinytag provides engineers, energy consultants, and building owners with a practical, scalable solution to capture the data that matters without overcomplicating the process.
Whether validating a retrofit, informing an upgrade, or helping a client understand long-term system health, Tinytag Ultra 2 and Energy Loggers deliver quiet, reliable insight from installation to ongoing assurance.
Find out more about out data loggers and more at this year’s EMEX show – find us on stand B90