Energy for domestic hot water in the Norwegian low emission society

The research project "Energy for domestic hot water in the Norwegian low emission society" is called "VarmtVann2030" and lasted from 2017 to 2021. In this project, building owners and suppliers worked together with SINTEF and NTNU to increase knowledge of the use of domestic hot water (DHW) in Norway. Based on knowledge about the use of hot water in different types of buildings, the team proposed more energy efficient and environmentally friendly solutions. In the future low-emission society, there is a need for efficient and smart DHW systems and management. It is expected that the energy demand for domestic hot water (DHW) will constitute a substantial part of the total energy demand in buildings also in the future. Knowledge about actual use of DHW is important when planning, designing and operating heating systems. However, the level of knowledge about the actual DHW demand in various Norwegian building categories is relatively low. Increased knowledge about the DHW use and system solutions is needed, as a basis for new technological solutions and smart management. VarmtVann2030 has focused on the building categories residential buildings, nursing homes and hotels. These building categories have a high demand for hot water and represent a large number of comparable buildings. Measurements are done in apartments from OBOS and Boligbygg, nursing homes from Drammen eiendom and Omsorgsbygg, and hotels from Olav Thon Gruppen. The product suppliers Armaturjonsson, Høiax, Geberit, Uponor and FM Mattsson Mora Group are also a part of the project. After project start-up spring 2017, information is collected for a number of apartment buildings, nursing homes and hotels. Existing historical measurements are collected, and provides information on how DHW is used in the buildings. The project has conducted detailed energy measurements in the heating central of 12 selected buildings: four nursing homes, four hotels and four apartment buildings. These measurements provide information on heat losses, daily variations, etc. The project has also done measurements in lab, focusing on heat losses in the DHW system. In addition, end user measurements are done in a hotel, to increase the knowledge of energy use and simultaneity of showers. Energy measurements are analyzed and published in about 18 research articles. A PhD student has finalized his work on statistical analysis of energy measurements. The project also includes 6 student thesis from 8 bachelor- and MSc students from Oslo MET, NMBU and NTNU. VarmtVann2030 provides the basis for new opportunities in the HVAC industry and among building owners, as well as improves the knowledge basis for planning, public administration and standardization work. Specification SN-NSPEK 3031 is revised, i.a. based on project results. The homepage for the project is www.sintef.no/varmtvann

Prosjektet VarmtVann2030 har økt kunnskapsnivået om energibruk og varmetap tilknyttet varmtvannssystemet, med særlig fokus på boligblokker, sykehjem og hoteller. Resultatene viser et betydelig potensial for mer energieffektive og miljøvennlige løsninger for bruk av tappevann i ulike bygningstyper. Resultater fra analysene er formidlet i blant annet 18 forskningsartikler, 2 SINTEF Fag rapporter og fagpresse. Prosjektet har bidratt til utdanningen av en PhD-student (NTNU) og 8 bachelor- og MSc studenter (Oslo MET, NMBU og NTNU). VarmtVann2030 gir grunnlag for nye muligheter i VVS-bransjen og blant byggeiere, samt bedrer grunnlaget for forvaltnings- og standardiseringsarbeid. Spesifikasjon SN-NSPEK 3031 er revidert, blant annet basert på prosjektresultater.

It is expected that the energy demand for domestic hot water (DHW) will be a substantial part of the total energy demand in future buildings. Heating DHW in residential buildings in Europe amounts to about 13% of the total household energy consumption. In very well insulated buildings, the relative importance of DHW is around 50%. Knowledge about actual DHW demands is important when planning, designing and operating heating systems. However, there is a relatively low level of knowledge about the actual DHW demand in various Norwegian building categories. In the future low-emission society, there is a need for efficient and smart DHW systems and management. Increased knowledge about the DHW use and system solutions is needed, as a basis for new technology solutions and smart management. The primary objective of VarmtVann2030 is to gain increased knowledge about the DHW demand in Norway, to document the energy efficiency of DHW distribution systems as well as to assess the impacts of different technology solutions in the DHW systems. Residential buildings, nursing homes and hotels will be in focus, since these building categories have a high demand for hot water and also represent a large number of comparable buildings. The project will be divided on 5 Work Packages (WP). WP 1 will register building and occupancy characteristics of the buildings, as a basis for selecting suitable buildings for field measurements. WP 2 will measure DHW consumption and energy loss in the DHW systems. WP 3 will be an energy analysis of DHW consumption and heat loss in the systems. WP 4 will identify important variables of DHW energy use. WP 5 will propose more energy efficient and environmentally friendly solutions for DHW systems based on analyses of existing conditions. VarmtVann2030 will provide the basis for new opportunities in the HVAC industry and among building owners, as well as improve the knowledge basis for planning, public administration and standardization work.