Fraunhofer Gesellschaft Hansastrasse 27c, München,

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1 Hospitals Partners: The County of South Jutland, DK Esbensen Consulting Engineers, DK Fachkrankenhaus Nordfriesland, DE MEYER Children Hospital, IT Torun City Hospital, PL Deventer Ziekenhuis, NL Fraunhofer ISE, DE Partner: Address: Fraunhofer Gesellschaft Hansastrasse 27c, 8686 München, Company responsible for this report: Fraunhofer Institute for Solar Energy Heidenhofstrasse 2, 7911, Freiburg, DE Tel.: Project Number: Title of Project: NNE HOSPITALS - Exemplar Energy Conscious European Hospitals and Health Care Buildings HOSPITALS web site: With the support from EU- DGTREN H O S P I T A L S Deliverable DWP 32 and DWP 33 Documentation and comparison of global performance data and lessons learned from monitoring for the five Hospitals projects primary energy [kwh/(m²a)] energy flow renewable energy primary energy end energy conversion losses: exploration, transport, power plant, grid,.. Aabenraa Hospital, DK U-Value [W/m²K] Deventer Hospital, NL newly auxiliary : pumps, fans controllers,.. heat recovery thermal losses: storage, distribution,... net space heating DHW Aabenraa, DK Deventer, NL Bredstedt, D Florence, I Torun, PL facade roof floor window doors Fachkrankenhaus Nordfriesland; D newly Meyer Children s Hospital, I newly Torun City Hospital, PL renovated renovated thermal energy total primary ,8 275, energy

2 EC THERMIE/ENERGY Final Report Hospitals - Exemplary Energy-Conscious European Hospitals and Health Care Buildings Project Number: NNE WP 3 Monitoring Christel Russ Fraunhofer Institute for Solar Energy Systems Freiburg Freiburg, 8 th June 26 rev :23 2 Fraunhofer ISE

3 Summary The state of repair of the existing hospital building stock, the special physiological and psychological situation of the patients and the intensive medical treatment result in a large energy demand. New concepts with a high-performance building envelope and an efficient energy supply system can reduce the energy demand of the hospitals and improve comfort for the patients, doctors and all other employees. Five demonstration projects, newly and renovated hospitals demonstrated that it is possible to decrease the demand for heating and and to increase comfort. The Aabenraa Hospital, DK, the Deventer Hospital, NL, the Fachkrankenhaus Nordfriesland in Bredstedt, D, the Meyer Children s Hospital in Florence, I, and the Torun City Hospital, PL have used various concepts to reduce the end energy demand and finally the primary energy needed for the hospitals. A very high insulation level, with a U-value for the walls between.2 W/(m²K) and.3 W/(m²K), for the roof between.12 and. 8 W/(m²K) and for the windows between 1.3 and 1.8 W/(m²K) (except Meyer Children s Hospital with 3.2 W/(m²K)), ensured a low energy demand. As a result of the planning for the hospital projects, we can state that they comply with the requirements of the project, the reduction of primary energy on average by about 3%. Between 46 kwh/(m²a)to 17 kwh/(m²a) primary energy can be saved. The primary energy saving for heating is between 26 kwh/(m²a) and 17 kwh/(m²a).the average reduction in air pollution is about 26% for CO 2 and 23% for SO 2 and NO x. The monitoring results of the first period after construction had been completed in Fachkrankenhaus Nordfriesland and Torun City Hospital confirm the predictions from the planning data. In Aabenraa Hospital the primary energy consumption is decreased by a further 28 % in comparison to the planning data. The results of the planning and monitoring demonstrated that the aim of the project has been achieved. rev :23 3 Fraunhofer ISE

4 Definition air pollution average of the annual temperature collector yield end energy form factor gross area of collector field gross envelope surface gross heated volume heating degree days net heated floor area solar radiation primary energy CHP HVAC DHW To compare the projects with each other, the air pollution must be related to the net heated area (kg/m²a). This is the annual average of the temperature over a long time or the value of the test reference year for the outdoor temperature. The collector yield is the thermal energy from the collector or the input from the collector to the storage system related to the collector gross area This is energy for total heating (space heating and domestic hot water), cooling and ; including useful energy and conversion efficiency (all heat losses by burners, storage, tubes, control etc.) with respect to the energy carrier used. This is the relation between the gross envelope surface and the gross heated volume, usually a basic parameter for primary energy demand. Collector data should be presented normalised by the gross system area. This includes the aperture as well as the frame. Envelope calculated with the exterior dimension of the facade including windows and doors, roof and floor area. Volume of the building calculated with the exterior dimensions of the building. These are the sum of the difference between the room temperature 2 C and the ambient temperature for all heating days. Heating days are all days with a daily average of the ambient temperature under 12 C. This is the sum of the net floor areas (indoor dimension) of all heated rooms including heated corridors, heated building stairways but not unheated building areas. The net floor space may change due to renovation or new construction. The relevant solar radiation is measured or calculated for the orientation and inclination of the solar collector. In the case of more than one orientation, the yearly sum of all orientations is normalised with the gross collector area. Shading of the collector array has to be considered by estimation or calculation. The end energy data are converted to primary energy use by applying suitable conversion factors. The same is done to calculate the related CO 2, NO x and SO 2 emission. The EU standard is used to convert the end energy for heating to primary energy and national standards are used for conversion of, based on GEMIS 4.1( Combined Heat and Power Heating Ventilation Air Conditioning Domestic Hot Water rev :23 4 Fraunhofer ISE

5 Contents 1 Project details 6 2 Aim and general description Aim of the project Description of the site Description of the performance of the monitoring/measurement system Measurement concepts 9 3 Construction, installation and commissioning Time schedule Cost 13 4 Operation and results Climate at the location of the hospitals Building Construction Building areas Form factor Insulation Level HVAC systems in the hospitals Aabenraa Hospital, DK Deventer Ziekenhuis, NL Fachkrankenhaus Nordfriesland, D Meyer Children s Hospital, I Torun City Hospital, PL End Energy Demand Primary energy Reduction of pollution Monitoring results End energy consumption for heating End energy consumption of Primary energy Air pollution 24 5 Summary - Lesson Learning from Project Monitoring 24 6 Literature 24 rev :23 5 Fraunhofer ISE

6 1 Project details Project Number: NNE Title of Project: Hospitals - Exemplary Energy-Conscious European Hospitals and Health Care Buildings Final Technical Report Period covered: from 1/1/22 to 31/12/25 Phases and/or Work packages covered: WP3 Monitoring Date of report: 8/6/26 SESAME-Sheet enclosed: yes/no Name of the company: Contact person: Address: Country Post-code, Town, Street 1 st Contractor 2 nd Contractor* Fraunhofer Institute for Solar Energy Systems Christel Russ Germany 7911 Freiburg Heidenhofstrasse 2 Tel:(country) (area) number Fax:(country) (area) number (mandatory) christel.russ@ise.fraunhofer.de Report prepared by: Name of company: Fraunhofer Institute for Solar Energy Systems ISE Freiburg Contact person: Christel Russ Address: Germany, 7911, Freiburg, Heidenhofstrasse 2 Tel: Fax: christel.russ@ise.fraunhofer.de If more contractors, extend the table as appropriate and number any consecutive cover pages i, ii, iii... rev :23 6 Fraunhofer ISE

7 2 Aim and general description 2.1 Aim of the project Hospitals and health care buildings usually need a high energy demand because the medical technology, the operating rooms and the special treatment methods lead to a high demand and large heat demand including steam generation in some projects. Furthermore, the sensitive patients in the wards and in the patients' rooms need special conditions for heating and in some cases for cooling. New building concepts in combination with high-efficiency energy techniques should reduce the energy demand in the hospitals and improve the micro-climatic conditions and the thermal comfort in the rooms. The main objective of this project is to document and analyse the energy consumption of the new energy-efficient hospitals and health-care buildings with respect to indoor and outdoor conditions. The objective of the planning process for the building design and the HVAC is to reduce the energy demand of the hospitals in relation to the present building standard by about 3 5 %. In a monitoring project, the building design and the energy demand of the five hospitals Aabenraa, DK, Deventer, NL, Meyer Children s Hospital Florence, I, Fachkrankenhaus Nordfriesland Bredstedt, D, Torun City Hospital, PL will be compared from the base state or standard building, over the planning data, to the measured results. Building and energy data were collected building renovation/new construction and in the planning stage. After renovation/new construction, the energy consumption was measured. All data have been analysed and the efficiency of the buildings has been compared. 2.2 Description of the site In co-operation with the project partners, the monitoring concept was developed, depending on the specific conditions of each hospital. To compare the building design and the energy demand of the hospitals, a structure for the data acquisition was developed. To collect important data on the location, the building design and the energy parameters, an evaluation format was created. This format distinguished three sections of information: the location, the building design and the energy consumption of the present building standards the planning data for the building design and the energy demand the measured data of the energy consumption of the new/renovated building. During the project duration, the data was recorded for the basic and the planning state. When the building process was finished, measurement of the energy was started. Because during the project duration, only the Aabenraa hospital and Fachkrankenhaus Nordfriesland Bredstedt were finished at the end of 24, the data there from January 25 to November 25 could be collected and analysed. In the Torun City Hospital, the renovation was realized step by step during the project duration, so the collected data for the energy consumption presented only an intermediate value during the renovation period. The project will be finished at the end of December 25 and the final data cannot be analysed in this report. The Meyer Children s Hospital Florence and the Deventer Hospital will be finished after the end of the project duration. For these projects, the energy consumption cannot be analysed in this monitoring report. rev :23 7 Fraunhofer ISE

8 2.3 Description of the performance of the monitoring/measurement system The basis of the comparative analysis based in all projects on the determination of the primary energy demand. The difference between the energy consumption in the base state and after the renovation/new construction characterizes the efficiency of the new building and HVAC concepts. End energy The measurement concept was developed for each of the projects. The important parameters are the measurement of the end energy for heat consumption - for heating, separately for space heating, hot water, sometimes for steam - for lighting, ventilation, controls, sometimes cooling, other appliances. Boundary conditions The climatic data for radiation, outdoor temperature and humidity are collected too. The measured data are collected as weekly values in an Excel sheet. Indoor conditions The temperature and humidity in the rooms are collected, iin Aabenraa Hospital and Meyer Children s Hospital in Florence the day-lighting coefficient is determined. Data evaluation In a comparative analysis the energy data are determined. On the basis of the end energy consumption, the primary energy and the air pollution can be calculated. The realisation of the measurement concept, the installation of the sensors, the measurement and data collection is managed by of the project partners. rev :23 8 Fraunhofer ISE

9 2.3.1 Measurement concepts In the following figures, the positions of the sensors in the energy system of the hospitals are shown. Aabenraa Hospital, DK In the Aabenraa Hospital district heating is used for space heating and hot water. Only the courtyard is integrated in the EU-HOSPITAL project. The hot water production is generated by a thermal solar collector and electric heater. Electricity is monitored separately for lighting, ventilation and pumps. The for controls is integrated into the total consumption. Furthermore, the room and ambient temperature, the humidity and the ventilation rate are measured. The day-lighting situation is estimated too. Lighting grid I_horizontal I_coll.plane Fans, hybrid ventilation Pumps, solar heating system Heating element, hot water storage tank Other district heating solar hot water storage tank heat meter heat meter hot water storage tank heat meter space heating domestic hot water ambient rooms air inlet humidity rooms ambient heat meter solar collector (liquid) ventilation air exchange daylighting DF 2 rooms DF office desk DF Courtyard -2 places Figure 1 Hospital Aabenraa, DK. HVAC scheme and position of the sensors. rev :23 9 Fraunhofer ISE

10 Deventer Hospital, NL A complex system is used for heating and cooling in the Deventer Hospital. Two heat pumps use the aquifer for cooling, space heating and hot water. The hot water generation is supported by CHP and a gas boiler. A heat pump is used for space heating and cooling. The air quality in special rooms will be monitored. Because the hospital is not finished during the project time the measurement program stated after the end of the project. Than DHW and cooling demand, the consumption for the heat pump (separately for heating and cooling), auxiliary for pumps, for lighting and the total,. furthermore temperatures of the outdoor air, rooms and the heat pump inlets and outlets, humidity and solar radiation are measured. grid natural gas grid gas meter CHP unit I_horiz wind speed total 38kV fan heat pump pumps heat cooling heat cooling heat meter lighting? temperature heat I heat II cool I Coll II aquifer aquifer volume flux heat pump volume flux air quality storage unit heat meter domestic hot water space heating cooling CO 2 - meter temperature ambient heat recovery in heat recovery out room air 4x supply air 4x humidity room 4x supply air exhaust air Figure 2 Deventer Hospital, NL, HVAC scheme with sensor positions. rev :23 1 Fraunhofer ISE

11 Fachkrankenhaus Nordfriesland, D With a gas boiler, heat for space heating and hot water is generated I the Fachkrankenhaus Nordfriesland. Electricity is used for ventilation, lighting, and other appliances. In the first measurement period, only the gas consumption, the total water consumption and the total consumption were measured. I_horizontal I_verticaly lighting/other grid fan natural gas gas meter gas boiler electricit total heat meter heat meter hot water storage tank heat meter space heating domestic hot water temperature ambient room humidity ambient room Figure 3 Fachkrankenhaus Nordfriesland, D, HVAC scheme with sensor position. rev :23 11 Fraunhofer ISE

12 Meyer Children s Hospital, I A complex energy supply system is installed in Meyer Children s Hospital in Florence. Cooling is provided by a heat pump. Cooling is supported by a chiller. With a heat pump supported by a gas boiler, heat was generated for the space heating and hot water The heat consumption for hot water and space heating and for cooling should be measure. Electricity meters should measure the for lighting, fans, pumps, heat pump, chiller and total consumption. electric meter* photovoltaic generator* chiller heat pump chiller heat meter heat meter I_horiz space cooling lighting? fan pumps temperature ambient humdity ambient grid natural gas total heat pump boiler heat meter heat meter storage unit domestic hot water humidity temperturature room heat meter space heating *PV is not integrated in the EU energy concept Figure 4 Meyer Children s Hospital, I HVAC scheme with sensor position. rev :23 12 Fraunhofer ISE

13 Torun City Hospital, PL In the City Hospital Torun the space heating and hot water, supplied by district heating, is measured. The consumption total, for auxiliary equipment and for heating is measured too. grid total lighting pumps,control district heating heat meter t heat meter space heating temperature ambient room air storage unit heat meter domestic hot water Figure 5 Torun City Hospital, PL HVAC scheme with sensor positions. 3 Construction, installation and commissioning Not relevant 3.1 Time schedule The time schedule was met for the central monitoring work package. 3.2 Cost The costs agree with the contract agreement. rev :23 13 Fraunhofer ISE

14 4 Operation and results If we compare the energy consumption of a building, we must consider the way from the energy generation to the energy consumption for space heating, hot water, cooling,. This is the way from primary energy over the end energy to the useful energy. The follow scheme described the energy flow from primary energy to the useful energy. energy flow heat recovery renewable energy primary energy end energy net space heating DHW conversion losses: exploration, transport, power plant, grid,.. auxiliary : pumps, fans controllers,.. thermal losses: storage, distribution,... The comparable base of the energy demand in all investigated hospitals is the primary energy. The primary energy is transformed to end energy by conversion losses for exploration, transport, power plants. The end energy (gas, oil, ) enters on the building periphery and a heating supply system generate useful energy (space heating, DHW, sometimes steam or cooling) by using auxiliary for pumps, fans and control and with thermal losses of storage and distribution. The conversion losses of the heating supply system are enclosed in the end energy. Renewable energy supported the energy consumption in the building and substitute primary energy. When renewable energy is used in a HVAC, the primary energy demand is decreased and the energy system is very efficient. Efficient building design and HVAC concepts leads to the reduction of the primary energy demand in the researched hospitals. In a monitoring we analyse both, the end energy and the primary energy during the planning and in the renovated/ newly hospitals. 4.1 Climate at the location of the hospitals The five hospitals are located in five different countries. The latitude and longitude of the projects in Aabenraa, Deventer and Bredstedt is not so various. The climatic parameters are not very different for these three hospital locations. We find different conditions in the temperate climate of Florence, with more solar radiation and a higher ambient temperature throughout the year. The heating degree days is very slow in comparison with the Deventer and Aabenraa hospital. Torun is located in a cold climatic with a high heating degree days over 41 kkd. Table 1 shows an overview of the locations and the climatic data for the hospitals. rev :23 14 Fraunhofer ISE

15 Table 1 Overview of the location and climate of the hospital projects Latitude [degree] (northern latitude) Longitude [degree] (- eastern longitude) DK NL D I PL Aabenraa Hospital Deventer Hospital Fachkrankenhaus Nordfriesland Meyer Children s Hospital Torun City Hospital Altitude [m] Average annual ambient temperature [ C] Minimum ambient temperature [ C] Heating degree days (basis 2 C/12 C) [kkd] Global solar radiation, horizontal plane (kwh/m²a] The local climatic conditions are important for the energy evaluation of a building. Figure 6 shows the solar radiation and the average of the ambient temperature for the demonstration projects. solar radiation [kwh/m²a] solar radiation - horizontal plane average of ambient temperature average of ambient temperature [ C] Aabenraa Hospital, DK** Deventer Hospital, NL* Fachkrankenhaus Meyer Children's Nordfriesland, D* Hospital, I* Torun City Hospital, P** * new building; **renovated building Figure 6 Local solar radiation and average of the ambient temperature for the five demonstration hospitals. We can see that Florence is the city with the highest solar radiation total and the highest ambient temperature in this five analysed projects. This are good conditions for a low energy demand for space heating at this location. A high solar radiation total is the basis for more passive solar energy usage in buildings, but there is in combination with high internal heat gains a danger of overheating in the summer. As a result, energy for cooling will be necessary. The planning results illustrated, that in the Florence hospital, more energy is needed for cooling than for space heating (figure 7). 7 rev :23 15 Fraunhofer ISE

16 End Energy Demand [kwh/m²a] space heating DHW cooling Figure 7 Meyer Children s Hospital, End energy demand for space heating and cooling (planning results) At the locations of the other hospitals, the solar radiation totals and the average of ambient temperature are all similar, but not so large than in Florence. We can expect that in a location with a lower ambient temperature, the energy demand for space heating will be higher. The number of heating degree-days is a value to characterise the space heating demand. The number of heating degree-days is the annual total of the daily average temperature difference between a room temperature of 2 C and the outdoor temperature for outdoor temperatures of 12 C and lower. Florence is the location with a small number of heating degree-days and a low energy demand for space heating of the Meyer Hospital. Torun, Poland is the location with the highest number of heating degree-days and a higher energy demand will be necessary to cover the space heating. Figure 8 illustrates the number of heating degree-days for the locations of the demonstration projects. 45 Heating degree days [Kd] Aabenraa Hospital, DK** Deventer Hospital, NL* Fachkrankenhaus Nordfriesland, D* Meyer Children's Hospital, I* Torun City Hospital, P** Figure 8 Heating degree days for the locations of the demonstration hospitals * new building; **renovated building rev :23 16 Fraunhofer ISE

17 4.2 Building Construction Building areas The building envelope in the new and renovated buildings are very different. The various areas of the building components are listed in table 4. To compare the buildings, the separate parts of the building envelope areas will be considered as ratios of the total envelope area. Figure 9 shows the different parts of the building envelope. On average about 22% of the envelope is used for the façade (without window area), the windows cover 11% of the envelope. On average, about 32% of the area is used for the roof and about 37 % for the floor. Table 2 Building envelope areas in the hospitals DK NL D I PL Aabenraa Hospital* Deventer Hospital areas of windows; total [m²] South East West North area of façade [m²] area of roof [m²] area of doors [m²] façade incl. area of floor [m²] *Only the new glazed courtyard is evaluated in the EU project. 12 Fachkrankenhaus Nordfriesland window doors 1128 Meyer Children s Hospital Torun City Hospital part of the building envelope [%] floor facade without windows window roof Deventer Hospital, NL Fachkrankenhaus Nordfriesland, D Meyer Children's Hospital, I Torun City Hospital, PL Figure 9 Different parts of the building envelope related on the total envelope area of the building rev :23 17 Fraunhofer ISE

18 The part of the windows on the envelope are only 11%, but in average the area of windows on the façade is on average 33%, a good ratio for a building. This proportion of window in the facade was found because of the special social function of the hospitals e.g. the wards are located in all building orientation (Torun, Deventer, Florence). The Fachkrankenhaus Nordfriesland has a complete glazed facade to the unglazed courtyard in the centre of the building and the proportion of glazing is 51%. Figure 1 shows on the left side the proportion of the windows related to the total façade of the hospitals and on the right side the proportion of the window area related to the building orientation. On average 34% or the main orientation of the windows is to the south. About 2 % of the windows are installed on the east and west sides of the building. The size of windows in the east, south and west orientations is important for the passive use of solar energy for space heating, but it presents the danger of overheating in summer. All windows in these orientations must be protected by a shading system during the summer and the rooms must have good ventilation. The Aabenraa Hospital used only the glazed courtyard with a large glass area in the roof. Its main orientation is south and north. In Meyer Children s Hospital Florence and Deventer Hospital, a cooling system is installed. In Aabenraa Hospital only exhaust air ventilation is used. In the courtyard in Aabenraa Hospital, a hybrid ventilation system is used fresh air enters via an earth-to-air heat exchanger and the outlet of the exhaust air is integrated into the glazed roof. In Torun City Hospital, ventilation gaps are installed under the ceiling and fresh air comes in through gaps in the frame of the windows. In Fachkrankenhaus Nordfriesland in Bredstedt a mechanical ventilation system with heat recovery is installed, but during the summer time a natural ventilation is used. In this building an active cooling system does not exist. rev :23 18 Fraunhofer ISE

19 part of window area on the total facade [%] Deventer Hospital, NL Fachkrankenhaus Meyer Children's Nordfriesland, D Hospital, I Torun City Hospital, PL part of windows on the facade [%] south east west north Aabenraa Hospital, DK Deventer Hospital, NL Fachkrankenhaus Nordfriesland, D Meyer Children's Hospital, I Torun City Hospital, PL Figure 1 Proportion of windows related to the façade (at the top) and to the orientation of the hospitals at the bottom). The main orientation of the windows in the hospitals depends on the principal axis of building. In Aabenraa, and Deventer Hospitals the main orientation of the windows is to the south and north, in the Fachkrankenhaus Nordfriesland in Bredstedt and Torun City Hospitals they are on the east and west and in the Meyer Children s Hospital in Florence it is on the south sides of the building Form factor The aim of the project is to reduce the energy demand in the hospitals by using innovative building constructions and components. There are different approaches to reduce the space heating demand in buildings. One step is to reduce the transmission heat losses in the building if the building envelope is reduced and the building have a compact structure. Table 3 gives information on the building dimensions and the form factor, the ratio of the gross envelope surface area to the gross building volume, in the new/renovated hospitals. A minimised envelope area leads to a small ratio of the building envelope aerate the gross building volume, the form factor of the building. The form factor is rev :23 19 Fraunhofer ISE

20 a measure of the compactness of the building. With a decreased envelope area, the form factor will be smaller and the transmission losses will be lower, making it simpler to achieve a lower heat demand. With the exception of the Fachkrankenhaus Nordfriesland and the Torun City Hospital, all demonstration hospitals have a very low form factor of about.3 m -1, they are very compact buildings. This is a good basis for a low energy demand of the buildings. Figure 11 illustrates the form factor of all demonstration buildings. The form factors of the Fachkrankenhaus NF Bredstedt and the Torun hospital are high. The Fachkrankenhaus is a square building with one floor. The four parts of the building surround a courtyard, so we find a large envelope area for this building. We have not calculated the form factor for Aabenraa Hospital, because only the courtyard is integrated into the EU project and this is a small part of the total hospital. form factor /Envelope area to gross volume) [per m] Deventer Hospital, NL Fachkrankenhaus Nordfriesland, D Meyer Children's Hospital, I Torun City Hospital, PL Figure 11 Planned values of the form factor, the ratio of the gross envelope area to the gross volume of the demonstration buildings. A small form factor results from the compact building structure in the hospitals of Deventer, Florence and Torun. rev :23 2 Fraunhofer ISE

21 Table 3 Information on the building dimensions of the five hospitals. DK NL D I PL Aabenraa Hospital* Deventer Hospital Fachkrankenhaus Nordfriesland Meyer Children s Hospital year of construction (new hospital) Torun City Hospital year of renovation type of construction light mixed massive massive massive number of heated storeys /5 basement (yes/no) no no no no yes if yes: heated/unheated unheated net heated floor area A N [m²] gross heated volume V e [m³] gross envelope surface area A [m²] form factor A/V e [m -1 ] number of buildings number of storeys /5 *only the courtyard is evaluated in the EU project, this is a small part of the total hospital Insulation Level The heat transfer coefficient, i.e. the heat flux through 1 m² envelope area with 1 K temperature difference between the indoor and outdoor sides of the building, or the U value, is important to characterise the transmission losses through the building envelope. If the U value is low, the transmission heat losses and finally the space heating demand will be low. In Table 4 and figure 12, the U values for the building components of the hospitals are shown. The facade, roof and the floor are very energy-efficient building components with a high insulation level, characterised by a low U value. The weak spot in the buildings are the windows with high U values, which lead to higher transmission losses. On the other hand, the windows contribute with solar gains to compensate for heat losses from the building. rev :23 21 Fraunhofer ISE

22 Table 4 Insulation level (U value) for the building components in the demonstration projects Aabenraa Hospital Deventer Hospital Fachkrankenhaus Nordfriesland Meyer Children s Hospital Torun City Hospital DK NL D I PL windows [W/(m²K)] wall [W/(m²K)].27.27,22.32,24 roof [W/(m²K)] ,2 doors [W/(m²K)] ground [W/(m²K)] windows greenhouse [W/(m²K)] U-Value [W/m²K] Aabenraa Hospital, DK Deventer Hospital, NL Fachkrankenhaus Nordfriesland, D Meyer Children's Hospital, I Torun City Hospital, PL facade roof floor window doors Figure 12 Planned value for the heat transfer coefficient U value - of the building components in the demonstration hospitals The U values for the building parts of the Meyer Children s Hospital are not as low as for the other locations. The transmission losses are lower than in the other hospitals, because more solar radiation, and higher ambient temperature exist in Florence (cf. 4.1). In the result, the demands on thermal insulation are not as important for the space heating demand. 4.3 HVAC systems in the hospitals Before the end energy and the primary energy are evaluated, we consider the different heating, hot water, cooling and ventilation systems of the hospitals. rev :23 22 Fraunhofer ISE

23 4.3.1 Aabenraa Hospital, DK Figure 13 Aabenra Hospital Courtyard after the renovation District heating is used for space heating and hot water. The generation of hot water is supported by total 15 m 2 thermal solar collector area, which provides an annual yield of about 54 kwh/(m²a), covering about 6% of the annual need for DHW. The renovation part includes covering three courtyards with glass and a well-insulated opaque roof, changing the courtyards from outdoor areas to real indoor areas. For the Aabenra Hospital, optimisation of the use of day-lighting has been given special attention, since optimum day-lighting conditions had to be provided not only in the glazed courtyards themselves but also in the rooms surrounding the glazed courtyards. For the hybrid ventilation - natural fan assisted ventilation - careful planning of the system controls was necessary in order to ensure that the patients would have optimum thermal comfort during summer, when the risk of overheating has been determined, and in winter, when the cold outdoor air needs preheating in order to provide draft-free fresh air to the building. Figure 14 The courtyards to be covered are B and C from the ward wings plus K from the operation wing, (left). The operating scheme of the hybrid ventilation is sketched on the right. The ventilation system in the glazed courtyards is designed as a displacement ventilation system. Fresh air is provided through external fresh air inlets and passed through the basement, assuring a constant air temperature around 16 C. Fresh air then passes a filter and a convector element. Exhaust is ensured via roof-integrated wind cowls, utilising the wind load to create sufficient under-pressure in the glass-covered courtyard to ensure the required air change of approximately 1. to 1.5 h -1. The roofintegrated wind cowls are equipped with assisting fans, to ensure a satisfactory ventilation level when the wind load is not sufficient. The hybrid ventilation system is controlled with a new Building Management System, BMS, including the necessary control points. For each building section, the rev :23 23 Fraunhofer ISE

24 BMS system controls a number of throttle motors, valve motors, sensors for fresh air temperature, and combined room air temperature and CO 2 sensors. All sensors are placed 1.6 m above floor level Deventer Hospital, NL Figure15 View of the Deventer Ziekenhuis on the left. Windows with radiator elements allow free arrangement of the rooms (right). The low-temperature heating system uses heat pumps for the standard load (ca. 8% of heat demand) combined with boilers for covering the peak loads. The standard demand for heating and cooling is met by an energy-efficient heat pump, which covers about 5% of the total thermal capacity. Only for the peak loads (ca. 3% of the total capacity) are conventional boilers used. Underground aquifers serve as warm and cold reservoirs. Heat pumps use warm wells as the source for heat generation. Condensing gas boilers are specified as peak load boilers. The ventilation air is pre-heated by humidity regenerators, and the regenerated humidity is used for the regulation of the air humidity. Heat recovery will be used, based on the application of a rotating air wheel. The buffered heating/cooling energy is used for pre-warming or precooling. Peak load cooling is provided with heat pumps for buffering the cooling energy (6% energy reduction). The remaining heat and cooling energy from the system is buffered in a heat-buffering layer of sand in the ground of the hospital. All cooling is provided by underground cold storage sources. Heat pumps can provide peak load cooling. Figure 16 Heating supply system in the Deventer Ziekenhuis. rev :23 24 Fraunhofer ISE

25 Domestic hot water The innovative energy system combines a low temperature system for the generation of heat with a high temperature system for the generation of hot tap water, which has to be kept at a high temperature to prevent legionella. The high temperature is generated by a Combined Heat and Power system (75% energy reduction), producing 5% heat and 35%. Combined Heat and Power generates the heat for domestic hot water, while is generated for immediate use in the hospital. All-air concept The "all-air concept" for ventilation is a low-temperature heating system, in which air-conditioning with ventilation air provides energy-efficient temperature control and draught-free distribution of air. The heat/coolness is distributed via the ventilation air ( all-air concept ). Instead of radiators, energyefficient short-distance heaters and control flaps are applied. Flexibility in making connections to the façade enables flexibility in using the floor space of the hospital. There are no installation elements near the façade. The heating ventilation system is therefore a highly efficient and flexible system enabling free arrangement and adaptation of the rooms. The specified system is based on an all-air concept for ventilation. Short-distance heaters and individual, motorised air-flow regulators in the supply duct of the ventilation air give flexibility in using spaces throughout the hospital. Figure 17 Cross-section with basic principle of the "all-air" systems in the rooms Fachkrankenhaus Nordfriesland, D Figure 18 Views of the Fachkrankenhaus Nordfriesland. The building and its surroundings (left), and part of the courtyard (right). Natural gas is the basis of the heating supply in the Fachkrankenhaus Nordfriesland. All wards use floor heating and radiators are installed in the bathrooms. The hot water is heated by the gas boiler and is collected in a storage tank. Figure 19 shows the schematic diagram of the heating system. rev :23 25 Fraunhofer ISE

26 preheating supply air space heating natural gas boiler floor heating radiator hot water storage domestic hot water Figure 19 Fachkrankenhaus Nordfriesland schematic diagram of heating system A mechanical ventilation system with heat recovery is installed to provide enough fresh air in the rooms. In the winter, the fresh air can be preheated with a hydraulic heater. Figure 2 illustrates the design of the ventilation system. supply air air to air heat exchanger supply air fan exhaust air fan air heater exhaust air Figure 2 Fachkrankenhaus Nordfriesland Schematic diagram of the mechanical ventilation system with heat recovery Meyer Children s Hospital, I Figure 21 Meyer Children s Hospital. View of the building (left), glazed corridor (right). The aim of the project is an energy-conscious design, where the term "conscious" means that the aim of energy saving has to be compatible with comfort. The concept of comfortable has to be applied case for case and depends on a difficult evaluation of three main factors: visual comfort, acoustic comfort and thermal comfort. All patients' rooms are designed for children: the use of suitable colours and materials on the walls, ceiling and floor, rev :23 26 Fraunhofer ISE

27 furniture and equipment was important. Each room has a large window looking onto green hills that are all around the Hospital. In terms of acoustic comfort, patient rooms are designed for no more than two children; the construction materials adopted and the position of the hospital are able to guarantee that noise does not penetrate into the patients' rooms. To the occupants, especially for children in a hospital, the most important consideration to create a comfortable place is thermal comfort, defined as that state of mind which expresses satisfaction with the thermal environment (as defined by ASHRAE). Heat pumps are used to generate heating and cooling. These are appropriate where both summer cooling and winter heating are required. Since the efficiency of the heat pumps drops with the outside temperature, they are not appropriate in cold climates. Heat is extracted from the cold outdoor air and added to the warm indoor air. Heat pumps are special air conditioners running in reverse during the winter. In the winter, a gas condensing combined boiler supports the generation of hot water. Figure 22 shows the heating and cooling scheme. Figure 22 Meyer Children s Hospital schematic diagram of the heating and cooling system A combination of shading and ventilation systems can keep the temperature to within 1 C above ambient. To save on energy for cooling, passive cooling and ventilation techniques are used as much as possible with air-conditioning only where necessary. A sun space functions as a buffer area for the building. The heated air is used to create solar drafts providing a natural air flow through the building. Trees will be planted around the hospital and part of the roof will be covered with grass. The respiration of the vegetation will provide a cool microclimate. A centralized energy management system selects the operational strategy in each case. Figure 23 Meyer Children s Hospital scheme of ventilation strategy rev :23 27 Fraunhofer ISE

28 4.3.5 Torun City Hospital, PL Figure 24 Hospital Torun, view after renovation In the Torun hospital, district heating from a CHP is used for space heating and hot water. A cooling system is not necessary, because the hospital is located in a cool climatic zone. A natural ventilation system is used. The fresh air enters the room through gaps at the top of the windows in the frame. The warm air will be brought outwards via a central duct system. Figure 25 Hospital Torun, schematic diagram of ventilation strategy 4.4 End Energy Demand An energy-efficient building is characterised by very low transmission and ventilation losses and a good ratio of usable solar and internal gains. Transmission losses can be reduced by a high insulation level. Ventilation losses can be decreased by using a controlled ventilation strategy with a mechanical ventilation system. If heat recovery is integrated into the ventilation system, the heat gains from heat recovery can contribute to reduce the heat losses and the energy demand for space heating can be decreased. Because is necessary for the heating system as auxiliary energy for pumps, controls, fans or as additional for space heating (heat pump) or direct electric heating, the integrated system for HVAC must be considered. To evaluate the total energy demand for space heating, DHW, ventilation, cooling and steam, the end energy (or better the primary energy) must be calculated. To evaluate the results of the planning of the new/renovated buildings, these hospitals are compared with existing old hospitals at the same location as the projects 1.. In table 5, the energy data are listed for the present building standard and the new /renovated building. 1 For the Deventer Hospital a reference building is used for the base state, based on the current standards in the Netherlands rev :23 28 Fraunhofer ISE

29 Thermal energy demand In figure 26, the end energy for heating in the hospitals is showed, for the base state and for the renovated or new buildings. The left graph in figure 26 shows the distribution of the thermal energy. In the base state, about 85 % of end energy for heating is used for space heating with the exception of the Meyer Hospital in Florence. Because of the temperate climate, the space heating demand is low, only 43%of the total heating demand. However, the cooling demand is about 5% of the thermal energy demand. Table 5 Energy demand of the hospitals - base and planning value End energy [kwh/m²a] total thermal energy Aabenraa Hospital, DK renovated Deventer Hospital, NL 1 newly Fachkrankenhaus Nordfriesland; D newly Meyer Children s Hospital, I newly Torun City Hospital, PL renovated * 155.* space heating ,3 176.* 48.* domestic hot water steam cooling total ** 45.** lighting fan controls cooling (11.) space heating CHP generated * including 22 kwh/m² for space heating and cooling ** without for cooling and heating, because this is integrated in the heating demand 1 For the Deventer Hospital, a reference building is used for the base state, based on the current standards in the Netherlands rev :23 29 Fraunhofer ISE

30 heating demand [kwh/m²] space heating cooling hot water steam newly newly newly renovated renovated Abenraa Deventer Fachkrankenhaus Meyer Childrens's Torun City Hospital, DK Hospital, NL Nordfriesland, D Hospital, I Hospital, PL heating demand [kwh/m²] space heating cooling hot water steam renovated newly newly newly reno- vated Abenraa Deventer Fachkrankenhaus Meyer Childrens's Torun City Hospital, DK Hospital, NL Nordfriesland, D Hospital, I Hospital, PL Figure 26 End energy demand of the demonstration projects for thermal energy - base state in comparison with the new/renovated building. At the top, the separate applications of the thermal energy are illustrated. At thebottom the end energy for the total thermal energy demand is shown. In the new/renovated buildings, the space heating demand has decreased, by about 43 % of the total thermal end energy demand. With the exception of Deventer, the hospitals achieved heat savings of about 3 5 % because very efficient insulation is used. In Florence the cooling demand amounts to 54 % of the thermal end energy demand. The best results with respect to reduction of end energy for the space heating demand appears in the Deventer hospital. Because we consider the end energy demand for space heating, the for the heat pump is also integrated into the space heating demand Therefore the proportion of the space heating is only 3% of the total thermal energy demand. In reality the net space heating demand is higher because the heat pump used 22 kwh/(m²a) to generate space heating with a COP = 4. rev :23 3 Fraunhofer ISE

31 Thus, the net space heating demand is 88 kwh/(m²a) and the total net space heating demand reached about 114 kwh/m²a. Under these conditions, the saved space heating demand with reference to the standard building is similar to the other hospitals. In Deventer, the hot water demand and the steam production have increased in the new building. In the new hospital, 16 % of the thermal energy is used to generate steam. The right side of figure 26 shows the total thermal end energy demand of the hospitals. After renovation/new construction, the average end energy savings for thermal energy amount to about 35 %. The Fachkrankenhaus NF Bredstedt achieved higher energy savings of 46 % because efficient insulation is used and energy for cooling and steam is not necessary. Electricity The end energy for includes the auxiliary energy for pumps, controls, fans, heating (heat pump) and the for lighting and cooling. In the Deventer and Florence hospitals, a heat pump is installed to provide space heating, hot water and cooling. The energy demand for this application is integrated into the total demand. Figure 27 illustrates the various applications of in the buildings. Except for Deventer, the largest amount of is used for lighting, followed by for fans in the ventilation system. In the Deventer Hospital, a CHP station will generate power to cover 3% of the necessary, so the end energy demand for is decreased. In the Deventer Hospital the largest share of is used for fans, about 45% of the total. In the newly hospitals, about 2 % of the total demand is used for the heat pump. Electricity is generated by CHP. This can used for ventilation, control and heat pump and the total consumption in the hospital will be minimized. The use of more than 35% for cooling in the Meyer Children s Hospital should be noted. The demand for the heat pumps is not specified in the planning documents. So in reality, the total demand must be higher than we calculated in the monitoring evaluation. In total, the energy demand for in the renovated/new hospitals is reduced on average by about 17% in Deventer, but only by 7% in Aabenraa, by 9 % in Bredstedt and by about 37 % in the Meyer Children s Hospital. In the Torun hospital, the demand was not changed after the renovation. demand [kwh/m²] lighting control heating fan cooling CHP-generation -35 newly newly newly Abenraa Hospital, DK Deventer Hospital, NL Fachkrankenhaus Meyer Children's Torun City Nordfriesland, D Hospital, I Hospital, PL renovated renovated rev :23 31 Fraunhofer ISE

32 12 total demand [kwh/m²] renovated newly newly newly renovated Abenraa Hospital, DK Deventer Hospital, NL Fachkrankenhaus Meyer Childrens's Torun City Nordfriesland, D Hospital, I Hospital, PL Figure 27 End energy demand of the demonstration projects for - base state in comparison with the new/renovated building. At the top of the figure, the separate applications of the demand are illustrated. At the bottom of the figure, the total demand is shown. In the Deventer and Florence hospitals, the energy demand for heat pumps and chiller is included Primary energy In the previous section, the thermal energy and demand of the hospitals was characterised. The best relation of the efficiency of a building is given by the value of the primary energy demand. The primary energy will be calculated by multiplication of the end energy with a specific factor. The primary energy gives a value which allows the energy saving of the projects to be compared on a common basis. The type and the number of energy-saving measures in the demonstration projects are very diverse. To compare the primary energy demand of all hospitals, the primary energy was calculated from the end energy, and multiplied by a factor, which is based on GEMIS for oil and gas factor 1.1, district heating plant, conventional fuels factor 1.3 CHP (district heating) factor.7. For, the specific factor for each country is used, because the components for generation is different in the various countries. D 2.89 DK 2.85 I 2.36 NL 2.59 PL 2.36 All hospitals have a good insulation level, and a highly efficient heating and ventilation strategy using heat pumps, CHP, district heating, solar collectors and/or mechanical ventilation systems with heat recovery. All projects are planned to reduce the primary energy demand by between 13% (Aabenraa) and 36% (Florence), on average by about 3%. Figure 28 shows the primary energy saving, in total 2 Global Emission Model for Integrated Systems, version 4.1, rev :23 32 Fraunhofer ISE