{"id":2739,"date":"2024-12-09T12:26:02","date_gmt":"2024-12-09T12:26:02","guid":{"rendered":"https:\/\/heatpumpingtechnologies.org\/annex62\/?page_id=2739"},"modified":"2025-09-12T14:39:45","modified_gmt":"2025-09-12T14:39:45","slug":"ch005-st-julien","status":"publish","type":"case_studies","link":"https:\/\/heatpumpingtechnologies.org\/project62\/case-studies\/ch005-st-julien\/","title":{"rendered":"CH005 St Julien"},"content":{"rendered":"\n
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Defying clich\u00e9s in Geneva, Switzerland<\/h2>\n<\/div><\/div>\n\n\n
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This retrofit of a 1972 building counters HP-sceptics\u2019 arguments on many different levels. Except for the roof, no renovations took place, the existing heat distribution system (including the radiators in the dwellings) remained and the back-up oil boiler was removed after two years without being used.  <\/p>\n<\/div>\n\n

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This existing MFH (multi-family building), built in 1972 in Geneva, contains 53 apartments over eight floors. It suffered no major envelope retrofit before this project and the total oil consumption amounted to 700 MWh\/yr (for space heating and domestic hot water of its 4\u2019049m\u00b2 of heated area).(Photo credit SIG, CSD Ing\u00e9nieurs SA)<\/em><\/p>\n<\/div>\n\n

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It is now equipped with a monovalent system comprising two industrial-type air-source HPs. In the last year of monitoring, the annual SPF was 2.3, including auxiliaries, with DHW consumption accounting for almost half of the total heat requirement. Operating errors were detected during the first year of monitoring, due to incorrect device settings, and were largely rectified by optimizing the control strategy, improving the system’s performance since commissioning.<\/p>\n<\/div>\n\n

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A 300 kW back-up oil boiler was initially kept in the system but after two years of monitoring it proved utterly useless and was removed.<\/p>\n<\/div>\n\n

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Lessons learned <\/strong><\/p>\n<\/div><\/div>\n\n\n

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