{"id":3411,"date":"2025-09-26T12:56:27","date_gmt":"2025-09-26T12:56:27","guid":{"rendered":"https:\/\/heatpumpingtechnologies.org\/project62\/?post_type=case_studies&#038;p=3411"},"modified":"2025-09-29T07:51:42","modified_gmt":"2025-09-29T07:51:42","slug":"nearly-zero-energy-building-nzeb-herzogenaurach-germany","status":"publish","type":"case_studies","link":"https:\/\/heatpumpingtechnologies.org\/project62\/case-studies\/nearly-zero-energy-building-nzeb-herzogenaurach-germany\/","title":{"rendered":"nearly Zero Energy Building (nZEB) Herzogenaurach, Germany"},"content":{"rendered":"<div class=\"container\">\n<figure class=\"wp-block-image size-full is-resized\"><img loading=\"lazy\" decoding=\"async\" width=\"1000\" height=\"667\" src=\"https:\/\/heatpumpingtechnologies.org\/content\/uploads\/sites\/75\/2025\/09\/herzocase.jpg\" alt=\"\" class=\"wp-image-3415\" style=\"width:507px;height:auto\" srcset=\"https:\/\/heatpumpingtechnologies.org\/content\/uploads\/sites\/75\/2025\/09\/herzocase.jpg 1000w, https:\/\/heatpumpingtechnologies.org\/content\/uploads\/sites\/75\/2025\/09\/herzocase-300x200.jpg 300w, https:\/\/heatpumpingtechnologies.org\/content\/uploads\/sites\/75\/2025\/09\/herzocase-768x512.jpg 768w, https:\/\/heatpumpingtechnologies.org\/content\/uploads\/sites\/75\/2025\/09\/herzocase-400x267.jpg 400w\" sizes=\"auto, (max-width: 1000px) 100vw, 1000px\" \/><\/figure>\n<\/div>\n\n<div class=\"container container--no-margin\">\n<p class=\"wp-block-paragraph \">In Germany, the \u201cKfW Effizienzhaus 40 Plus\u201d is defined by heating demand of 40 % and transmission heat loss of 55 % compared to the EnEV minimal requirement as well as additional technology equipment. This includes mainly a self-generated energy system, an electrical storage and mechanical ventilation with heat recovery. To demonstrate a more ambitious level, the terraced houses are also designed as plus energy building, which means a negative annual final energy demand including the whole energy balance incl. appliances.<\/p>\n<\/div>\n\n<div class=\"container container--no-margin\">\n<p class=\"wp-block-paragraph \">The terraced houses, achieving \u201cKfW Effizienzhaus 40 Plus\u201d, has been monitored for two years from April 2018 &#8211; March 2020. The all-electric building is equipped with two central 17 kW ground-source heat pumps (B0\/W35), eight decentral heat pumps for providing DHW and a 88 kWp solar PV-system. Beside the buffer storage cascade of 2800 litres and eight DHW-storage tanks of 200 litre each, a 40 kWh battery serves as additional energy storage in order to increase the PV self-consumption. Moreover, decentral mechanical ventilation devices with 86 % heat recovery are installed. The ground-source is used for free-cooling in summer operation. The plus energy balance has been reached in the two monitoring years. The ground-coupled heat pump system achieved an SPF of 5.6 and the DHW heat pumps achieved an SPF of 4.0, while the SPF of the whole energy system is 3.4. Optimized PV operation of the heat pumps led to an increase of the supply cover factor from about 32 % to around 37 %.<\/p>\n<\/div>\n\n<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 \"><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><em>Herzogenaurach, Germany<\/em><\/td><td>Number of HP<\/td><td>2 for heating, 8 for DHW<\/td><\/tr><tr><td>Construction<\/td><td><em>201<\/em>7<\/td><td>Heat distribution<\/td><td>Underfloor + radiators<\/td><\/tr><tr><td>Heated area<\/td><td><em>1200 m\u00b2<\/em><\/td><td>Heat source<\/td><td><em><em>Geothermal<\/em><\/em><\/td><\/tr><tr><td>No. of apartments<\/td><td>8<\/td><td>Type of system<\/td><td><em>HP Only<\/em><\/td><\/tr><tr><td>Level of insulation<\/td><td><em>Very good<\/em><\/td><td>Model<\/td><td>Alpha innoTec SWCV 162<\/td><\/tr><tr><td><\/td><td><\/td><td>Geothermal heat exchanger <\/td><td>7x 100 m<\/td><\/tr><tr><td><strong>Heating sytem<\/strong><\/td><td><\/td><td><strong>Domestic Hot Water (DHW)<\/strong><\/td><td><\/td><\/tr><tr><td>Heating temperature<\/td><td><em>35\u202f\u00b0C<\/em><\/td><td>DHW demand <\/td><td><em>20.9 kWh\/(m2a)<\/em><\/td><\/tr><tr><td>Installed power<\/td><td><em>13 kW<\/em><\/td><td>Battery <\/td><td>40 kWh<\/td><\/tr><tr><td>Heat demand<\/td><td><em>9.6 kWh\/(m2a)<\/em><\/td><td>DMW storage tanks<\/td><td>8x 200 L<\/td><\/tr><tr><td><strong>Other information<\/strong><\/td><td><\/td><td><\/td><td><\/td><\/tr><tr><td>Climatic zone<\/td><td><em>Cfb<\/em><\/td><td><\/td><td><\/td><\/tr><tr><td>SPF of whole energy system <\/td><td>3.4<\/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 container--no-margin\">\n<p class=\"wp-block-paragraph \"><\/p>\n<\/div>\n\n<div class=\"container\">\n<figure class=\"wp-block-image size-full is-resized\"><img loading=\"lazy\" decoding=\"async\" width=\"917\" height=\"554\" src=\"https:\/\/heatpumpingtechnologies.org\/content\/uploads\/sites\/75\/2025\/09\/bildschirmfoto26-9-2025145118.jpeg\" alt=\"\" class=\"wp-image-3412\" style=\"width:683px;height:auto\" srcset=\"https:\/\/heatpumpingtechnologies.org\/content\/uploads\/sites\/75\/2025\/09\/bildschirmfoto26-9-2025145118.jpeg 917w, https:\/\/heatpumpingtechnologies.org\/content\/uploads\/sites\/75\/2025\/09\/bildschirmfoto26-9-2025145118-300x181.jpeg 300w, https:\/\/heatpumpingtechnologies.org\/content\/uploads\/sites\/75\/2025\/09\/bildschirmfoto26-9-2025145118-768x464.jpeg 768w, https:\/\/heatpumpingtechnologies.org\/content\/uploads\/sites\/75\/2025\/09\/bildschirmfoto26-9-2025145118-400x242.jpeg 400w\" sizes=\"auto, (max-width: 917px) 100vw, 917px\" \/><\/figure>\n<\/div>\n\n<div class=\"container\">\n<figure class=\"wp-block-image is-resized\"><a class=\"wp-block-button__link has-vivid-cyan-blue-color has-white-background-color has-text-color has-background has-text-align-center wp-element-button\" href=\"https:\/\/heatpumpingtechnologies.org\/content\/uploads\/sites\/75\/2025\/09\/factsheetherzogenaurach.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: IEA HPT Project (annex) 49<\/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>In Germany, the \u201cKfW Effizienzhaus 40 Plus\u201d is defined by heating demand of 40 % and transmission heat loss of&#8230;<\/p>\n","protected":false},"author":62,"featured_media":0,"menu_order":0,"template":"","filters":[],"markets":[24],"applications":[7,41],"class_list":["post-3411","case_studies","type-case_studies","status-publish","hentry","markets-germany","applications-buildings","applications-multi-family-buildings"],"acf":[],"_links":{"self":[{"href":"https:\/\/heatpumpingtechnologies.org\/project62\/wp-json\/wp\/v2\/case_studies\/3411","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\/62"}],"version-history":[{"count":5,"href":"https:\/\/heatpumpingtechnologies.org\/project62\/wp-json\/wp\/v2\/case_studies\/3411\/revisions"}],"predecessor-version":[{"id":3422,"href":"https:\/\/heatpumpingtechnologies.org\/project62\/wp-json\/wp\/v2\/case_studies\/3411\/revisions\/3422"}],"wp:attachment":[{"href":"https:\/\/heatpumpingtechnologies.org\/project62\/wp-json\/wp\/v2\/media?parent=3411"}],"wp:term":[{"taxonomy":"filters","embeddable":true,"href":"https:\/\/heatpumpingtechnologies.org\/project62\/wp-json\/wp\/v2\/filters?post=3411"},{"taxonomy":"markets","embeddable":true,"href":"https:\/\/heatpumpingtechnologies.org\/project62\/wp-json\/wp\/v2\/markets?post=3411"},{"taxonomy":"applications","embeddable":true,"href":"https:\/\/heatpumpingtechnologies.org\/project62\/wp-json\/wp\/v2\/applications?post=3411"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}