The effect of low ventilation rates (1 or 0.5 air change per hour) on thermal comfort and ventila... more The effect of low ventilation rates (1 or 0.5 air change per hour) on thermal comfort and ventilation effectiveness was experimentally studied in a simulated residential room equipped with radiant floor heating/cooling and mixing ventilation systems. The tests were performed for various positions of supply and extract air terminals and different winter and summer boundary conditions. Vertical air temperature, operative temperature and air velocity profiles were measured in different positions in the room, and equivalent temperatures were derived, in order to characterize thermal comfort.Contaminant removal effectiveness (CRE) and local air change index was measured in order to characterize ventilation effectiveness in the occupied zone. Acceptable thermal comfort was found in most experiments; however, air temperature differences higher than 3 °C occurred when floor cooling was combined with unconditioned outdoor air supply, i.e. at the supply air temperatures higher than the room a...
Eine Bewertung der Kombina-tion von Solarkollektor-Ab-sorptionskältemaschine und Fußbodenkühlung ... more Eine Bewertung der Kombina-tion von Solarkollektor-Ab-sorptionskältemaschine und Fußbodenkühlung war die Aufgabe eines europäischen Forschungsvorhabens unter dem JOULE III-Programm. Die Veröffentlichung gibt einen Überblick über einige erreich-te Ergebnisse. Das Projekt ist in mehrere Teilaufgaben wie Fußbodenkühlung (Leistung, Regelung), Solarkollektoren (Neuentwicklung Flach-und Röhrenkollektoren), Absorp-tionskältemaschine (neuer Prototyp) aufgeteilt. Radiant floor cooling with absorp-tion heat pump and solar collectors The combination of solar collector, absorption heat pump and radiant floor cooling was stu-died in an European research project under the JOULE III -Program. This paper presents an overview of some of the results. The project was split up in several parts like floor cooling (cooling capacity, control), solar collector (new development of flat plate and an evacuated tube collector) and absorption heat pump (new prototype). F ür größere Gebäude mit hohen in-ternen L...
The purpose of this paper is to investigate what the heat exchange coefficient for floor cooling ... more The purpose of this paper is to investigate what the heat exchange coefficient for floor cooling is and to study the consequences of using different reference temperatures in the space for calculating the heat exchange between the floor surface and the space. Sometimes the heat exchange is calculated as total heat exchange, convection and radiation combined. In other cases, it
This study is an outcome of Elforsk, project number 344-060, Bæredygtige Energi-Plus huse (Sustai... more This study is an outcome of Elforsk, project number 344-060, Bæredygtige Energi-Plus huse (Sustainable plus-energy houses). The focus of this report is to document the approach and the results of different analyses concerning a plus-energy, single family house. The house was designed for an international student competition, Solar Decathlon Europe 2012 and after the competition it was used as a full-scale experimental facility for one year. During this period, different heating and cooling strategies were tested and the performance of the house regarding the thermal indoor environment and energy was monitored. This report is structured as follows. Chapter 1 presents the project and briefly explains the different phases of the project. The details of the house’s construction and its HVAC system are explained in Chapter 2, along with the energy efficiency measures and innovations. Chapter 3 introduces the investigations carried out in detail, with respect to different phases of the pr...
Sixteen subjects evaluated the indoor environment in four experiments with different combinations... more Sixteen subjects evaluated the indoor environment in four experiments with different combinations of ventilation systems and radiant heating/cooling systems. In the first two tests, the simulated residential room was equipped either by a mixing ventilation system supplying warm air for space heating or by a combination of radiant floor heating and mixing ventilation system. The vertical air temperature distribution was more uniform for floor heating. The discomfort due to cold feet/lower legs was higher for warm air heating, but no significant difference in thermal perceptions between the two mixing ventilation systems was found. The next two tests simulated an office room during summer, ventilated and cooled either by a displacement ventilation system alone or by a displacement ventilation system combined with radiant floor cooling. Displacement ventilation combined with floor cooling had lower floor temperature, warmer supply air, and less homogeneous vertical temperature profile,...
The performance of radiant heating systems (floor heating, ceiling panels) is relatively well doc... more The performance of radiant heating systems (floor heating, ceiling panels) is relatively well documented. Water based systems, where pipes are embedded in the building structure, are now being increasingly used for cooling purposes. Several theoretical studies based on the use of computer simulations have been published, but very little is reported on the actual performance in existing buildings. There are still uncertainties on how such systems operate and on how well the space temperatures under varying external and internal load is kept within the comfort range. To study this aspect, field measurements of thermal comfort conditions were made in several buildings with radiant surface cooling systems. The systems comprise floor cooling, wall cooling and cooling with pipes embedded in the concrete slabs between each floor in a multi storey building. Long term measurements of operative, air, surface, system and external temperatures have been carried out. The analysis of the data sho...
Since the end of the 80's, intensive work on standardisation has been taken place in Europe. ... more Since the end of the 80's, intensive work on standardisation has been taken place in Europe. The goal is to establish uniform standards in Europe among the countries who are members of EFTA and the European Union. Inside the building and HVAC area, mainly standards for products have been published. Now design of systems and calculation methods are also being standardised. The present paper presents the standardisation work going on in Europe related to the design and operation of heating systems in buildings. Standards for calculation of building energy demand, heat load calculations, system design, installation and operation, sizing of heat emitter, and for calculation of yearly energy performance will be presented and discussed.
Due to intensive use of energy and high costs in several European countries it is often debated i... more Due to intensive use of energy and high costs in several European countries it is often debated if air-conditioning of buildings is recommendable or should be prohibited by law. Of course, air-conditioning will give better control of the indoor temperature and then improve comfort and productivity. But there also exist many examples of discomfort in air-conditioned buildings due to draught, noise and sick building syndrome. By air-conditioning, heating, cooling and ventilation are achieved alone by air, where the cooling and heating requirements determine the amount of required air circulation. Alternatively, the heating and sensible component of cooling may be done by hydronic radiant heating and cooling systems, where pipes are embedded in concrete slabs between each storey. The system may be combined with a ventilation system, where the amount of outside air is based on the requirements for acceptable are quality. This paper discusses the possibilities and limitations of such hea...
Indoor terminal units can be defined as the building elements that use different heat transfer me... more Indoor terminal units can be defined as the building elements that use different heat transfer mechanisms and media to emit and remove heat or moisture from indoor spaces (e.g. hydronic radiant heating and cooling systems, fan-coil units, active beams). Indoor temperature and humidity fields depend on the chosen terminal units. Terminal units differ in their capabilities of addressing sensible and latent loads, methods of heat emission or removal, maximum heating and cooling capacities, medium of energy distribution, and local or total volume conditioning. In the present study, operation characteristics, possibilities and limitations of different terminal units were specified. Considered terminal units were radiant heating and cooling systems, all-air systems (mixing, displacement, and personalized ventilation), passive and active beams. The results were summarized in a table, which aims at providing a reference for terminal unit selection during the design phases of HVAC systems.
The effect of low ventilation rates (1 or 0.5 air change per hour) on thermal comfort and ventila... more The effect of low ventilation rates (1 or 0.5 air change per hour) on thermal comfort and ventilation effectiveness was experimentally studied in a simulated residential room equipped with radiant floor heating/cooling and mixing ventilation systems. The tests were performed for various positions of supply and extract air terminals and different winter and summer boundary conditions. Vertical air temperature, operative temperature and air velocity profiles were measured in different positions in the room, and equivalent temperatures were derived, in order to characterize thermal comfort.Contaminant removal effectiveness (CRE) and local air change index was measured in order to characterize ventilation effectiveness in the occupied zone. Acceptable thermal comfort was found in most experiments; however, air temperature differences higher than 3 °C occurred when floor cooling was combined with unconditioned outdoor air supply, i.e. at the supply air temperatures higher than the room a...
Eine Bewertung der Kombina-tion von Solarkollektor-Ab-sorptionskältemaschine und Fußbodenkühlung ... more Eine Bewertung der Kombina-tion von Solarkollektor-Ab-sorptionskältemaschine und Fußbodenkühlung war die Aufgabe eines europäischen Forschungsvorhabens unter dem JOULE III-Programm. Die Veröffentlichung gibt einen Überblick über einige erreich-te Ergebnisse. Das Projekt ist in mehrere Teilaufgaben wie Fußbodenkühlung (Leistung, Regelung), Solarkollektoren (Neuentwicklung Flach-und Röhrenkollektoren), Absorp-tionskältemaschine (neuer Prototyp) aufgeteilt. Radiant floor cooling with absorp-tion heat pump and solar collectors The combination of solar collector, absorption heat pump and radiant floor cooling was stu-died in an European research project under the JOULE III -Program. This paper presents an overview of some of the results. The project was split up in several parts like floor cooling (cooling capacity, control), solar collector (new development of flat plate and an evacuated tube collector) and absorption heat pump (new prototype). F ür größere Gebäude mit hohen in-ternen L...
The purpose of this paper is to investigate what the heat exchange coefficient for floor cooling ... more The purpose of this paper is to investigate what the heat exchange coefficient for floor cooling is and to study the consequences of using different reference temperatures in the space for calculating the heat exchange between the floor surface and the space. Sometimes the heat exchange is calculated as total heat exchange, convection and radiation combined. In other cases, it
This study is an outcome of Elforsk, project number 344-060, Bæredygtige Energi-Plus huse (Sustai... more This study is an outcome of Elforsk, project number 344-060, Bæredygtige Energi-Plus huse (Sustainable plus-energy houses). The focus of this report is to document the approach and the results of different analyses concerning a plus-energy, single family house. The house was designed for an international student competition, Solar Decathlon Europe 2012 and after the competition it was used as a full-scale experimental facility for one year. During this period, different heating and cooling strategies were tested and the performance of the house regarding the thermal indoor environment and energy was monitored. This report is structured as follows. Chapter 1 presents the project and briefly explains the different phases of the project. The details of the house’s construction and its HVAC system are explained in Chapter 2, along with the energy efficiency measures and innovations. Chapter 3 introduces the investigations carried out in detail, with respect to different phases of the pr...
Sixteen subjects evaluated the indoor environment in four experiments with different combinations... more Sixteen subjects evaluated the indoor environment in four experiments with different combinations of ventilation systems and radiant heating/cooling systems. In the first two tests, the simulated residential room was equipped either by a mixing ventilation system supplying warm air for space heating or by a combination of radiant floor heating and mixing ventilation system. The vertical air temperature distribution was more uniform for floor heating. The discomfort due to cold feet/lower legs was higher for warm air heating, but no significant difference in thermal perceptions between the two mixing ventilation systems was found. The next two tests simulated an office room during summer, ventilated and cooled either by a displacement ventilation system alone or by a displacement ventilation system combined with radiant floor cooling. Displacement ventilation combined with floor cooling had lower floor temperature, warmer supply air, and less homogeneous vertical temperature profile,...
The performance of radiant heating systems (floor heating, ceiling panels) is relatively well doc... more The performance of radiant heating systems (floor heating, ceiling panels) is relatively well documented. Water based systems, where pipes are embedded in the building structure, are now being increasingly used for cooling purposes. Several theoretical studies based on the use of computer simulations have been published, but very little is reported on the actual performance in existing buildings. There are still uncertainties on how such systems operate and on how well the space temperatures under varying external and internal load is kept within the comfort range. To study this aspect, field measurements of thermal comfort conditions were made in several buildings with radiant surface cooling systems. The systems comprise floor cooling, wall cooling and cooling with pipes embedded in the concrete slabs between each floor in a multi storey building. Long term measurements of operative, air, surface, system and external temperatures have been carried out. The analysis of the data sho...
Since the end of the 80's, intensive work on standardisation has been taken place in Europe. ... more Since the end of the 80's, intensive work on standardisation has been taken place in Europe. The goal is to establish uniform standards in Europe among the countries who are members of EFTA and the European Union. Inside the building and HVAC area, mainly standards for products have been published. Now design of systems and calculation methods are also being standardised. The present paper presents the standardisation work going on in Europe related to the design and operation of heating systems in buildings. Standards for calculation of building energy demand, heat load calculations, system design, installation and operation, sizing of heat emitter, and for calculation of yearly energy performance will be presented and discussed.
Due to intensive use of energy and high costs in several European countries it is often debated i... more Due to intensive use of energy and high costs in several European countries it is often debated if air-conditioning of buildings is recommendable or should be prohibited by law. Of course, air-conditioning will give better control of the indoor temperature and then improve comfort and productivity. But there also exist many examples of discomfort in air-conditioned buildings due to draught, noise and sick building syndrome. By air-conditioning, heating, cooling and ventilation are achieved alone by air, where the cooling and heating requirements determine the amount of required air circulation. Alternatively, the heating and sensible component of cooling may be done by hydronic radiant heating and cooling systems, where pipes are embedded in concrete slabs between each storey. The system may be combined with a ventilation system, where the amount of outside air is based on the requirements for acceptable are quality. This paper discusses the possibilities and limitations of such hea...
Indoor terminal units can be defined as the building elements that use different heat transfer me... more Indoor terminal units can be defined as the building elements that use different heat transfer mechanisms and media to emit and remove heat or moisture from indoor spaces (e.g. hydronic radiant heating and cooling systems, fan-coil units, active beams). Indoor temperature and humidity fields depend on the chosen terminal units. Terminal units differ in their capabilities of addressing sensible and latent loads, methods of heat emission or removal, maximum heating and cooling capacities, medium of energy distribution, and local or total volume conditioning. In the present study, operation characteristics, possibilities and limitations of different terminal units were specified. Considered terminal units were radiant heating and cooling systems, all-air systems (mixing, displacement, and personalized ventilation), passive and active beams. The results were summarized in a table, which aims at providing a reference for terminal unit selection during the design phases of HVAC systems.
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Papers by Bjarne Olesen