{"id":3538,"date":"2026-03-17T11:14:25","date_gmt":"2026-03-17T11:14:25","guid":{"rendered":"https:\/\/heatpumpingtechnologies.org\/project62\/?post_type=case_studies&#038;p=3538"},"modified":"2026-03-17T11:14:25","modified_gmt":"2026-03-17T11:14:25","slug":"ch006-daru-geneva-switzerland","status":"publish","type":"case_studies","link":"https:\/\/heatpumpingtechnologies.org\/project62\/case-studies\/ch006-daru-geneva-switzerland\/","title":{"rendered":"CH006 Daru, Geneva, Switzerland"},"content":{"rendered":"<div class=\"container container--no-margin\">\n<p class=\"wp-block-paragraph \"><\/p>\n<\/div>\n\n<div class=\"container container--no-margin\">\n<p class=\"wp-block-paragraph \">This project concerns the replacement of an existing gas heating system by a hybrid HP+gas solution in an existing<br>multifamily building. With the goal of having the maximum annual heat production from HP origin, six air\/water heat<br>pumps were implemented on the rooftop. One of the previous gas boilers was kept for the peak loads in winter.<\/p>\n<\/div>\n\n<div class=\"container\">\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"436\" height=\"351\" src=\"https:\/\/heatpumpingtechnologies.org\/content\/uploads\/sites\/75\/2026\/03\/screenshot-2026-03-17-115545.png\" alt=\"\" class=\"wp-image-3539\" srcset=\"https:\/\/heatpumpingtechnologies.org\/content\/uploads\/sites\/75\/2026\/03\/screenshot-2026-03-17-115545.png 436w, https:\/\/heatpumpingtechnologies.org\/content\/uploads\/sites\/75\/2026\/03\/screenshot-2026-03-17-115545-300x242.png 300w, https:\/\/heatpumpingtechnologies.org\/content\/uploads\/sites\/75\/2026\/03\/screenshot-2026-03-17-115545-400x322.png 400w\" sizes=\"auto, (max-width: 436px) 100vw, 436px\" \/><\/figure>\n<\/div>\n\n<div class=\"container container--no-margin\">\n<p class=\"wp-block-paragraph \">The existing MFH (multi-family building), built in 1992 in Geneva, contains 68 apartments, within 4 floors, plus commercial establishments on the ground floor (restaurant, bakery, \u2026). It suffered no major envelope retrofit before this project and the total gas consumption amounted to 1\u2019000 MWh\/yr (for space heating and domestic hot water of 7\u2019563m\u00b2). (Photo credit SIG, CSD Ing\u00e9nieurs SA).<\/p>\n<\/div>\n\n<div class=\"container container--no-margin\">\n<p class=\"wp-block-paragraph \"><strong>Lessons learned<\/strong><\/p>\n<\/div>\n\n<div class=\"container container--no-margin\">\n<ul class=\"wp-block-list\">\n<li>Major air HP constraints encountered: noise emissions, vibrations, safety\u2026 These implied important costs and planning work.<\/li>\n\n\n\n<li>Hybrid HP+gas system: optimization of the gas boiler switching point is crutial for a good HP share in the overall heat production (specially with an old boiler without variable power output).<\/li>\n\n\n\n<li>The constraints of the old heat and DHW distribution system should not be underestimated.<\/li>\n<\/ul>\n<\/div>\n\n<div class=\"container container--no-margin\">\n<p class=\"wp-block-paragraph \"><strong>Key Facts<\/strong><\/p>\n<\/div>\n\n<div class=\"container container--no-margin\">\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><tbody><tr><td><strong>Building<\/strong><\/td><td><\/td><td><strong>Heat Pump and Source<\/strong><\/td><td><\/td><\/tr><tr><td>Location<\/td><td>Geneva, Switzerland<\/td><td>Heat source<\/td><td>ambient air <\/td><\/tr><tr><td>Construction<\/td><td>1992<\/td><td>Number of HPs<\/td><td>6<\/td><\/tr><tr><td>Heated area<\/td><td>7563m\u00b2<\/td><td>Installed power <\/td><td>6 x 30 kW HP (A2\/W50)<\/td><\/tr><tr><td>Level of insulation<\/td><td>low (1992 standard)<\/td><td>Operation mode<\/td><td>hybrid (HP + gas)<\/td><\/tr><tr><td><\/td><td><\/td><td>Existing gas boiler<\/td><td>240 kW<\/td><\/tr><tr><td><\/td><td><\/td><td><\/td><td><\/td><\/tr><tr><td><strong>Heat demand<\/strong><\/td><td>700 MWh\/yr<\/td><td><strong>Other Information<\/strong><\/td><td><\/td><\/tr><tr><td>Space heating<\/td><td>71% of demand<\/td><td>Electricity cons.<\/td><td>190 MWh\/yr<\/td><\/tr><tr><td>Heating temperature<\/td><td>60 \u00b0C (@ -7\u00b0 ext)<\/td><td>Gas cons<\/td><td>230 MWh\/yr<\/td><\/tr><tr><td>Heat distribution<\/td><td>radiators<\/td><td>Investments costs<\/td><td>unknown<\/td><\/tr><tr><td>Domestic hot water<\/td><td>39% of demand<\/td><td>PV installation<\/td><td>no<\/td><\/tr><tr><td>Type of system<\/td><td>centralized<\/td><td><\/td><td><\/td><\/tr><tr><td>Max. temperature<\/td><td>60 \u00b0C<\/td><td><\/td><td><\/td><\/tr><tr><td>Circulation system<\/td><td>yes<\/td><td><\/td><td><\/td><\/tr><\/tbody><\/table><\/figure>\n<\/div>\n\n<div class=\"container container--no-margin\">\n<hr class=\"wp-block-separator has-alpha-channel-opacity\" \/>\n<\/div>\n\n<div class=\"container\">\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"475\" src=\"https:\/\/heatpumpingtechnologies.org\/content\/uploads\/sites\/75\/2026\/03\/screenshot-2026-03-17-120948-1024x475.png\" alt=\"\" class=\"wp-image-3541\" srcset=\"https:\/\/heatpumpingtechnologies.org\/content\/uploads\/sites\/75\/2026\/03\/screenshot-2026-03-17-120948-1024x475.png 1024w, https:\/\/heatpumpingtechnologies.org\/content\/uploads\/sites\/75\/2026\/03\/screenshot-2026-03-17-120948-300x139.png 300w, https:\/\/heatpumpingtechnologies.org\/content\/uploads\/sites\/75\/2026\/03\/screenshot-2026-03-17-120948-768x356.png 768w, https:\/\/heatpumpingtechnologies.org\/content\/uploads\/sites\/75\/2026\/03\/screenshot-2026-03-17-120948-400x186.png 400w, https:\/\/heatpumpingtechnologies.org\/content\/uploads\/sites\/75\/2026\/03\/screenshot-2026-03-17-120948.png 1505w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/figure>\n<\/div>\n\n<div class=\"container container--no-margin\">\n<hr class=\"wp-block-separator has-alpha-channel-opacity\" \/>\n<\/div>\n\n<div class=\"container container--no-margin\">\n<p class=\"wp-block-paragraph \"><strong>Description of the technical concept<\/strong><\/p>\n<\/div>\n\n<div class=\"container container--no-margin\">\n<p class=\"wp-block-paragraph \">This project, part of a Geneva pilot program to replace fossil fuel boilers by heat pumps (HP) in MFH, concerns the replacement of a gas heating system by a hybrid HP+gas heating system. With the goal of having a maximum heat production from HP origin, six 30 kW air\/water heat pumps were implemented on the rooftop. For the peak loads in winter, a 240 kW gas boiler was maintained. It should be mentioned that:<\/p>\n<\/div>\n\n<div class=\"container container--no-margin\">\n<ul class=\"wp-block-list\">\n<li>The building rooftop was retrofitted before the HPs were installed. No other retrofit action was undertaken.<\/li>\n\n\n\n<li>The heat and DHW distribution system was not modified.<\/li>\n<\/ul>\n<\/div>\n\n<div class=\"container container--no-margin\">\n<p class=\"wp-block-paragraph \">The 6 HPs are divided into 2 groups of 3. 1 group exclusively for space heating, the other can either do space heating or domestic hot water. The gas boiler, when functioning, can work simultanioulsy with the HPs.<\/p>\n<\/div>\n\n<div class=\"container\">\n<figure class=\"wp-block-image is-resized\"><a href=\"https:\/\/heatpumpingtechnologies.org\/content\/uploads\/sites\/75\/2026\/03\/casestudysheetchdarunew.pdf\"><img loading=\"lazy\" decoding=\"async\" width=\"845\" height=\"237\" src=\"https:\/\/heatpumpingtechnologies.org\/annex62\/wp-content\/uploads\/sites\/75\/2024\/02\/fact-sheet-button-pic.png\" alt=\"\" class=\"wp-image-2196\" style=\"width:333px;height:auto\" srcset=\"https:\/\/heatpumpingtechnologies.org\/content\/uploads\/sites\/75\/2024\/02\/fact-sheet-button-pic.png 845w, https:\/\/heatpumpingtechnologies.org\/content\/uploads\/sites\/75\/2024\/02\/fact-sheet-button-pic-300x84.png 300w, https:\/\/heatpumpingtechnologies.org\/content\/uploads\/sites\/75\/2024\/02\/fact-sheet-button-pic-768x215.png 768w, https:\/\/heatpumpingtechnologies.org\/content\/uploads\/sites\/75\/2024\/02\/fact-sheet-button-pic-400x112.png 400w\" sizes=\"auto, (max-width: 845px) 100vw, 845px\" \/><\/a><\/figure>\n<\/div>\n\n<div class=\"container container--no-margin\">\n<p class=\"wp-block-paragraph \">Case study delivered by:\u00a0<em>Team Switzerland (CSD Ing\u00e9nieurs SA)<\/em><\/p>\n<\/div>\n\n<div class=\"container container--no-margin\">\n<p class=\"wp-block-paragraph \"><\/p>\n<\/div>","protected":false},"excerpt":{"rendered":"<p>This project concerns the replacement of an existing gas heating system by a hybrid HP+gas solution in an existingmultifamily building&#8230;.<\/p>\n","protected":false},"author":69,"featured_media":0,"menu_order":0,"template":"","filters":[],"markets":[],"applications":[],"class_list":["post-3538","case_studies","type-case_studies","status-publish","hentry"],"acf":[],"_links":{"self":[{"href":"https:\/\/heatpumpingtechnologies.org\/project62\/wp-json\/wp\/v2\/case_studies\/3538","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/heatpumpingtechnologies.org\/project62\/wp-json\/wp\/v2\/case_studies"}],"about":[{"href":"https:\/\/heatpumpingtechnologies.org\/project62\/wp-json\/wp\/v2\/types\/case_studies"}],"author":[{"embeddable":true,"href":"https:\/\/heatpumpingtechnologies.org\/project62\/wp-json\/wp\/v2\/users\/69"}],"version-history":[{"count":1,"href":"https:\/\/heatpumpingtechnologies.org\/project62\/wp-json\/wp\/v2\/case_studies\/3538\/revisions"}],"predecessor-version":[{"id":3543,"href":"https:\/\/heatpumpingtechnologies.org\/project62\/wp-json\/wp\/v2\/case_studies\/3538\/revisions\/3543"}],"wp:attachment":[{"href":"https:\/\/heatpumpingtechnologies.org\/project62\/wp-json\/wp\/v2\/media?parent=3538"}],"wp:term":[{"taxonomy":"filters","embeddable":true,"href":"https:\/\/heatpumpingtechnologies.org\/project62\/wp-json\/wp\/v2\/filters?post=3538"},{"taxonomy":"markets","embeddable":true,"href":"https:\/\/heatpumpingtechnologies.org\/project62\/wp-json\/wp\/v2\/markets?post=3538"},{"taxonomy":"applications","embeddable":true,"href":"https:\/\/heatpumpingtechnologies.org\/project62\/wp-json\/wp\/v2\/applications?post=3538"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}