The Experts below are selected from a list of 12855 Experts worldwide ranked by ideXlab platform
Jarek Kurnitski - One of the best experts on this subject based on the ideXlab platform.
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financial viability of energy efficiency measures in a new Detached House design in finland
Applied Energy, 2012Co-Authors: Arto Saari, Targo Kalamees, Juha Jokisalo, Rasmus Michelsson, Kari Alanne, Jarek KurnitskiAbstract:Abstract This study analyses alternative energy-saving design concepts for a typical new Detached House design in Finland. The impact of these design concepts on the construction costs and on the total delivered energy needs of the building were calculated, and the financial viability of the different concepts analysed. Different thermal insulation and airtightness properties of the building envelope and different ventilation’s heat recovery efficiency assumptions were tested in the analysis work. Other variations modelled included the heating mode: direct electrical floor heating, or floor heating via an air or ground source heat pump. Among these alternatives, the estimated annual consumption of purchased energy for running the Household varied extensively, in the range 57–182 kW h/net floor m2. With the real interest rate set at 3%, the payback period was shortest for the air source heat pumps (9 years). When a heat pump was installed in a House with higher energy consumption, the payback period was 7 years, and if it was installed in the ‘ultra low-energy’ House designs, the payback period was over 13 years. Investment to thick thermal insulation of envelope was unattractive in Finland. The results of this study can be generalized to similar climates and techno-economic environments.
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cost optimal and nearly zero nzeb energy performance calculations for residential buildings with rehva definition for nzeb national implementation
Energy and Buildings, 2011Co-Authors: Jarek Kurnitski, Targo Kalamees, Mika Vuolle, Arto Saari, Jouko Niemela, Teet TarkAbstract:Abstract This study determined cost optimal and nearly zero energy building (nZEB) energy performance levels following the REHVA definition and energy calculation methodology for nZEB national implementation. Cost optimal performance levels – meaning the energy performance leading to minimum life cycle cost – were calculated with net present value method according to the cost optimal draft regulation. The seven-step procedure was developed to conduct cost optimal and nZEB energy performance levels calculations in systematic and robust scientific fashion. It was shown that cost optimal primary energy use can be calculated with limited number of energy simulations as only four construction concepts were simulated and cost calculated. The procedure includes the specification of building envelope components based on specific heat loss coefficient and systems calculation with post processing of energy simulation results, without the need to use iterative approach or optimization algorithm. Model calculations were conducted for Estonian reference Detached House to analyse the difference between the cost optimal and nZEB energy performance levels. Cost optimal energy performance level of Estonian reference Detached House was 110 kW h/(m2 a) primary energy including all energy use with domestic appliances and it was significantly lower than the current minimum requirement of 180 kW h/(m2 a).
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simulation of the heating performance of the kang system in one chinese Detached House using biomass
Energy and Buildings, 2011Co-Authors: Guangyu Cao, Juha Jokisalo, Guohui Feng, Lin Duanmu, Mika Vuolle, Jarek KurnitskiAbstract:A traditional Chinese heating system, the Chinese Kang, is used by 175 million people in Detached Houses in the rural regions of China, especially in Northeast China. This system utilizes biomass such as corn stalks, straw, corncob and energy plants as the heat sources. The objective of this paper is to establish a set of models to simulate the energy performance of the Kang heating system in one Chinese Detached House. An experimental field study was carried out to collect practical parameters in a newly constructed Chinese Detached House. The dynamic performance of the Kang heating system was simulated by using IDA-ICE 4.0 embedded with an empirical model built in the field study. The results show that the simulation can obtain good overall agreement with the field measurement results. It was confirmed that the Kang model created by IDA-ICE 4.0 is capable of simulating the performance of the Kang system and of calculating energy consumption in the Detached House. Moreover, the result reveals that the thermal environment in the present Chinese Detached House is still poor during the severe cold season if only the Kang system is used to heat the whole House.
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building leakage infiltration and energy performance analyses for finnish Detached Houses
Building and Environment, 2009Co-Authors: Juha Jokisalo, Minna Korpi, Targo Kalamees, Jarek Kurnitski, Juha VinhaAbstract:Abstract This study focuses on the relation between the airtightness of a building envelope, infiltration, and energy use of a typical modern Finnish Detached House in the cold climate of Finland. The study is conducted with an empirically tested dynamic IDA-ICE simulation model of a Detached House. The effect of several factors, such as Finnish climate and wind conditions, balance of ventilation system and leakage distribution, on infiltration was studied and a simple adapted model for the rough estimation of annual infiltration in Finnish Detached Houses was determined from the numerical simulation results. The energy impact of infiltration is also studied, taking into account the infiltration heat recovery effect. According to the results, infiltration causes about 15–30% of the energy use of space heating including ventilation in the typical Finnish Detached House. The average infiltration rate and heat energy use increase almost linearly with the building leakage rate n50. Finland can be roughly divided into two zones based on the average infiltration rate of Detached Houses, for which stack-induced infiltration is typically dominant, regardless of the climate zone. The infiltration heat recovery effect is minor in the studied Detached House.
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a comparison of measured and simulated air pressure conditions of a Detached House in a cold climate
Journal of Building Physics, 2008Co-Authors: Juha Jokisalo, Targo Kalamees, Jarek Kurnitski, Lari Eskola, Kai Jokiranta, Juha VinhaAbstract:This study discusses the evaluation exercise of a multi-zone infiltration model of an existing two-storey Detached House in the cold Finnish climate. This study is performed by comparing the simulated and measured pressure conditions of the building during a 3-week test period in the heating season. The simulations are carried out using a dynamic simulation tool, IDA-ICE, which combines whole-building energy simulation and infiltration modeling. The initial data of the building model are obtained with extensive field measurements, including measurements of the airtightness and air leakage distribution of the envelope and performance of the ventilation system. The study shows that the model is realistically able to predict the air pressure conditions of a Detached House in a cold climate and it is suitable for detailed infiltration and energy analyses. The model allows the prediction of the effects of leakage distribution, airflows between rooms and floors, building leakage rate, pressure conditions, and c...
Juha Jokisalo - One of the best experts on this subject based on the ideXlab platform.
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indoor temperature conditions and energy demand of a finnish Detached House in a changing climate
E3S Web of Conferences, 2021Co-Authors: Azin Velashjerdi Farahani, Juha Jokisalo, Natalia Korhonen, Risto KosonenAbstract:This study investigated the effect of passive strategies (orientation, thermal mass of building structure, window opening, and window properties) and the usage of an active cooling system on energy demand and indoor temperature conditions of a Detached House in Finland in the current (TRY 2012) and future climatic conditions (2050). So that nine different cases were defined and simulated. The goal was to improve the indoor temperature conditions in the cooling season and analyze the effects of global warming on energy demand. Regarding the results of passive strategies, in the current climate, using openable windows would be the best solution for decreasing the cooling demand and providing acceptable indoor air temperature of the spaces. In this case, 96% of the time in the cooling season, the indoor temperature is below the maximum recommended indoor temperature (27 °C) of the thermal environment category III of the standard EN 15251 and EN 16798–1. While using an active cooling system in the hall of the upper floor, it is the only studied solution that can provide thermal comfort in all the spaces during the cooling season in both current and future climate based on the standards. In the future 2050 climate, the heating demand decreases much more than the amount of increase in the cooling demand. So that the total electricity demand of electrically heated Detached Houses in the future climate would be less than in the current climate.
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financial viability of energy efficiency measures in a new Detached House design in finland
Applied Energy, 2012Co-Authors: Arto Saari, Targo Kalamees, Juha Jokisalo, Rasmus Michelsson, Kari Alanne, Jarek KurnitskiAbstract:Abstract This study analyses alternative energy-saving design concepts for a typical new Detached House design in Finland. The impact of these design concepts on the construction costs and on the total delivered energy needs of the building were calculated, and the financial viability of the different concepts analysed. Different thermal insulation and airtightness properties of the building envelope and different ventilation’s heat recovery efficiency assumptions were tested in the analysis work. Other variations modelled included the heating mode: direct electrical floor heating, or floor heating via an air or ground source heat pump. Among these alternatives, the estimated annual consumption of purchased energy for running the Household varied extensively, in the range 57–182 kW h/net floor m2. With the real interest rate set at 3%, the payback period was shortest for the air source heat pumps (9 years). When a heat pump was installed in a House with higher energy consumption, the payback period was 7 years, and if it was installed in the ‘ultra low-energy’ House designs, the payback period was over 13 years. Investment to thick thermal insulation of envelope was unattractive in Finland. The results of this study can be generalized to similar climates and techno-economic environments.
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simulation of the heating performance of the kang system in one chinese Detached House using biomass
Energy and Buildings, 2011Co-Authors: Guangyu Cao, Juha Jokisalo, Guohui Feng, Lin Duanmu, Mika Vuolle, Jarek KurnitskiAbstract:A traditional Chinese heating system, the Chinese Kang, is used by 175 million people in Detached Houses in the rural regions of China, especially in Northeast China. This system utilizes biomass such as corn stalks, straw, corncob and energy plants as the heat sources. The objective of this paper is to establish a set of models to simulate the energy performance of the Kang heating system in one Chinese Detached House. An experimental field study was carried out to collect practical parameters in a newly constructed Chinese Detached House. The dynamic performance of the Kang heating system was simulated by using IDA-ICE 4.0 embedded with an empirical model built in the field study. The results show that the simulation can obtain good overall agreement with the field measurement results. It was confirmed that the Kang model created by IDA-ICE 4.0 is capable of simulating the performance of the Kang system and of calculating energy consumption in the Detached House. Moreover, the result reveals that the thermal environment in the present Chinese Detached House is still poor during the severe cold season if only the Kang system is used to heat the whole House.
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building leakage infiltration and energy performance analyses for finnish Detached Houses
Building and Environment, 2009Co-Authors: Juha Jokisalo, Minna Korpi, Targo Kalamees, Jarek Kurnitski, Juha VinhaAbstract:Abstract This study focuses on the relation between the airtightness of a building envelope, infiltration, and energy use of a typical modern Finnish Detached House in the cold climate of Finland. The study is conducted with an empirically tested dynamic IDA-ICE simulation model of a Detached House. The effect of several factors, such as Finnish climate and wind conditions, balance of ventilation system and leakage distribution, on infiltration was studied and a simple adapted model for the rough estimation of annual infiltration in Finnish Detached Houses was determined from the numerical simulation results. The energy impact of infiltration is also studied, taking into account the infiltration heat recovery effect. According to the results, infiltration causes about 15–30% of the energy use of space heating including ventilation in the typical Finnish Detached House. The average infiltration rate and heat energy use increase almost linearly with the building leakage rate n50. Finland can be roughly divided into two zones based on the average infiltration rate of Detached Houses, for which stack-induced infiltration is typically dominant, regardless of the climate zone. The infiltration heat recovery effect is minor in the studied Detached House.
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a comparison of measured and simulated air pressure conditions of a Detached House in a cold climate
Journal of Building Physics, 2008Co-Authors: Juha Jokisalo, Targo Kalamees, Jarek Kurnitski, Lari Eskola, Kai Jokiranta, Juha VinhaAbstract:This study discusses the evaluation exercise of a multi-zone infiltration model of an existing two-storey Detached House in the cold Finnish climate. This study is performed by comparing the simulated and measured pressure conditions of the building during a 3-week test period in the heating season. The simulations are carried out using a dynamic simulation tool, IDA-ICE, which combines whole-building energy simulation and infiltration modeling. The initial data of the building model are obtained with extensive field measurements, including measurements of the airtightness and air leakage distribution of the envelope and performance of the ventilation system. The study shows that the model is realistically able to predict the air pressure conditions of a Detached House in a cold climate and it is suitable for detailed infiltration and energy analyses. The model allows the prediction of the effects of leakage distribution, airflows between rooms and floors, building leakage rate, pressure conditions, and c...
Targo Kalamees - One of the best experts on this subject based on the ideXlab platform.
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financial viability of energy efficiency measures in a new Detached House design in finland
Applied Energy, 2012Co-Authors: Arto Saari, Targo Kalamees, Juha Jokisalo, Rasmus Michelsson, Kari Alanne, Jarek KurnitskiAbstract:Abstract This study analyses alternative energy-saving design concepts for a typical new Detached House design in Finland. The impact of these design concepts on the construction costs and on the total delivered energy needs of the building were calculated, and the financial viability of the different concepts analysed. Different thermal insulation and airtightness properties of the building envelope and different ventilation’s heat recovery efficiency assumptions were tested in the analysis work. Other variations modelled included the heating mode: direct electrical floor heating, or floor heating via an air or ground source heat pump. Among these alternatives, the estimated annual consumption of purchased energy for running the Household varied extensively, in the range 57–182 kW h/net floor m2. With the real interest rate set at 3%, the payback period was shortest for the air source heat pumps (9 years). When a heat pump was installed in a House with higher energy consumption, the payback period was 7 years, and if it was installed in the ‘ultra low-energy’ House designs, the payback period was over 13 years. Investment to thick thermal insulation of envelope was unattractive in Finland. The results of this study can be generalized to similar climates and techno-economic environments.
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cost optimal and nearly zero nzeb energy performance calculations for residential buildings with rehva definition for nzeb national implementation
Energy and Buildings, 2011Co-Authors: Jarek Kurnitski, Targo Kalamees, Mika Vuolle, Arto Saari, Jouko Niemela, Teet TarkAbstract:Abstract This study determined cost optimal and nearly zero energy building (nZEB) energy performance levels following the REHVA definition and energy calculation methodology for nZEB national implementation. Cost optimal performance levels – meaning the energy performance leading to minimum life cycle cost – were calculated with net present value method according to the cost optimal draft regulation. The seven-step procedure was developed to conduct cost optimal and nZEB energy performance levels calculations in systematic and robust scientific fashion. It was shown that cost optimal primary energy use can be calculated with limited number of energy simulations as only four construction concepts were simulated and cost calculated. The procedure includes the specification of building envelope components based on specific heat loss coefficient and systems calculation with post processing of energy simulation results, without the need to use iterative approach or optimization algorithm. Model calculations were conducted for Estonian reference Detached House to analyse the difference between the cost optimal and nZEB energy performance levels. Cost optimal energy performance level of Estonian reference Detached House was 110 kW h/(m2 a) primary energy including all energy use with domestic appliances and it was significantly lower than the current minimum requirement of 180 kW h/(m2 a).
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building leakage infiltration and energy performance analyses for finnish Detached Houses
Building and Environment, 2009Co-Authors: Juha Jokisalo, Minna Korpi, Targo Kalamees, Jarek Kurnitski, Juha VinhaAbstract:Abstract This study focuses on the relation between the airtightness of a building envelope, infiltration, and energy use of a typical modern Finnish Detached House in the cold climate of Finland. The study is conducted with an empirically tested dynamic IDA-ICE simulation model of a Detached House. The effect of several factors, such as Finnish climate and wind conditions, balance of ventilation system and leakage distribution, on infiltration was studied and a simple adapted model for the rough estimation of annual infiltration in Finnish Detached Houses was determined from the numerical simulation results. The energy impact of infiltration is also studied, taking into account the infiltration heat recovery effect. According to the results, infiltration causes about 15–30% of the energy use of space heating including ventilation in the typical Finnish Detached House. The average infiltration rate and heat energy use increase almost linearly with the building leakage rate n50. Finland can be roughly divided into two zones based on the average infiltration rate of Detached Houses, for which stack-induced infiltration is typically dominant, regardless of the climate zone. The infiltration heat recovery effect is minor in the studied Detached House.
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a comparison of measured and simulated air pressure conditions of a Detached House in a cold climate
Journal of Building Physics, 2008Co-Authors: Juha Jokisalo, Targo Kalamees, Jarek Kurnitski, Lari Eskola, Kai Jokiranta, Juha VinhaAbstract:This study discusses the evaluation exercise of a multi-zone infiltration model of an existing two-storey Detached House in the cold Finnish climate. This study is performed by comparing the simulated and measured pressure conditions of the building during a 3-week test period in the heating season. The simulations are carried out using a dynamic simulation tool, IDA-ICE, which combines whole-building energy simulation and infiltration modeling. The initial data of the building model are obtained with extensive field measurements, including measurements of the airtightness and air leakage distribution of the envelope and performance of the ventilation system. The study shows that the model is realistically able to predict the air pressure conditions of a Detached House in a cold climate and it is suitable for detailed infiltration and energy analyses. The model allows the prediction of the effects of leakage distribution, airflows between rooms and floors, building leakage rate, pressure conditions, and c...
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infiltration simulation in a Detached House empirical model validation
2007Co-Authors: Juha Jokisalo, Targo Kalamees, Jarek Kurnitski, Lari Eskola, Kai Jokiranta, Juha VinhaAbstract:SUMMARY This study discusses the empirical validation of a multi-zone infiltration model of an existing two-storey Detached House in the cold Finnish climate. Empirical validation was performed by comparing simulated and measured pressure conditions of the building during a three-week test period in the heating season. The simulations were carried out using a dynamic simulation tool, IDA-ICE, which combines whole-building energy simulation and infiltration modelling. The initial data of the building model were obtained with extensive field measurements including the measurements of airtightness and leakage distribution of the envelope and performance of a ventilation system. According to the results, pressure conditions are slightly negative on the first floor and positive on the second due to the stack effect in the heating season. The empirical validation shows that the correspondence between the simulated and measured pressure conditions is good and the studied building model can be used for the infiltration and energy analyses.
Juha Vinha - One of the best experts on this subject based on the ideXlab platform.
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building leakage infiltration and energy performance analyses for finnish Detached Houses
Building and Environment, 2009Co-Authors: Juha Jokisalo, Minna Korpi, Targo Kalamees, Jarek Kurnitski, Juha VinhaAbstract:Abstract This study focuses on the relation between the airtightness of a building envelope, infiltration, and energy use of a typical modern Finnish Detached House in the cold climate of Finland. The study is conducted with an empirically tested dynamic IDA-ICE simulation model of a Detached House. The effect of several factors, such as Finnish climate and wind conditions, balance of ventilation system and leakage distribution, on infiltration was studied and a simple adapted model for the rough estimation of annual infiltration in Finnish Detached Houses was determined from the numerical simulation results. The energy impact of infiltration is also studied, taking into account the infiltration heat recovery effect. According to the results, infiltration causes about 15–30% of the energy use of space heating including ventilation in the typical Finnish Detached House. The average infiltration rate and heat energy use increase almost linearly with the building leakage rate n50. Finland can be roughly divided into two zones based on the average infiltration rate of Detached Houses, for which stack-induced infiltration is typically dominant, regardless of the climate zone. The infiltration heat recovery effect is minor in the studied Detached House.
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a comparison of measured and simulated air pressure conditions of a Detached House in a cold climate
Journal of Building Physics, 2008Co-Authors: Juha Jokisalo, Targo Kalamees, Jarek Kurnitski, Lari Eskola, Kai Jokiranta, Juha VinhaAbstract:This study discusses the evaluation exercise of a multi-zone infiltration model of an existing two-storey Detached House in the cold Finnish climate. This study is performed by comparing the simulated and measured pressure conditions of the building during a 3-week test period in the heating season. The simulations are carried out using a dynamic simulation tool, IDA-ICE, which combines whole-building energy simulation and infiltration modeling. The initial data of the building model are obtained with extensive field measurements, including measurements of the airtightness and air leakage distribution of the envelope and performance of the ventilation system. The study shows that the model is realistically able to predict the air pressure conditions of a Detached House in a cold climate and it is suitable for detailed infiltration and energy analyses. The model allows the prediction of the effects of leakage distribution, airflows between rooms and floors, building leakage rate, pressure conditions, and c...
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infiltration simulation in a Detached House empirical model validation
2007Co-Authors: Juha Jokisalo, Targo Kalamees, Jarek Kurnitski, Lari Eskola, Kai Jokiranta, Juha VinhaAbstract:SUMMARY This study discusses the empirical validation of a multi-zone infiltration model of an existing two-storey Detached House in the cold Finnish climate. Empirical validation was performed by comparing simulated and measured pressure conditions of the building during a three-week test period in the heating season. The simulations were carried out using a dynamic simulation tool, IDA-ICE, which combines whole-building energy simulation and infiltration modelling. The initial data of the building model were obtained with extensive field measurements including the measurements of airtightness and leakage distribution of the envelope and performance of a ventilation system. According to the results, pressure conditions are slightly negative on the first floor and positive on the second due to the stack effect in the heating season. The empirical validation shows that the correspondence between the simulated and measured pressure conditions is good and the studied building model can be used for the infiltration and energy analyses.
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measurement and simulations of air pressure in a two storey Detached House and in a five storey apartment building
2007Co-Authors: Targo Kalamees, Jarek Kurnitski, Juha Jokisalo, Juha VinhaAbstract:Air pressure conditions in a two-storey Detached House and in a five-storey apartment building are analyzed using data from field measurements and computer simulations. The effects of airtightness, ventilation rate, air leakage distributions, and outdoor environmental conditions on air pressure conditions in a Detached House were simulated on a multi-zone simulation model using the IDA ICE simulation program. There is almost always a positive and negative air pressure difference across the building envelope in Detached Houses and in apartment buildings. During winter, in Detached Houses there is continuous positive air pressure at ceiling level on the top floor and negative pressure at floor level on the bottom floor. For Detached Houses, value of air pressure difference across the building envelope at the 10% percentile level is close to ±10 Pa. The control of air pressure difference in normal and leaky Houses is difficult: ± 15 differences in ventilation airflows have only a minor influence on the air pressure difference. To control air pressure differences, the balancing of ventilation systems in airtight Houses is very important.
Keramatollah Akbari - One of the best experts on this subject based on the ideXlab platform.
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influence of indoor air conditions on radon concentration in a Detached House
Journal of Environmental Radioactivity, 2013Co-Authors: Keramatollah Akbari, Jafar Mahmoudi, Mahdi GhanbariAbstract:Radon is released from soil and building materials and can accumulate in residential buildings. Breathing radon and radon progeny for extended periods hazardous to health and can lead to lung cance ...
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Influence of indoor air conditions on radon concentration in a Detached House.
Journal of environmental radioactivity, 2012Co-Authors: Keramatollah Akbari, Jafar Mahmoudi, GhanbariAbstract:Radon is released from soil and building materials and can accumulate in residential buildings. Breathing radon and radon progeny for extended periods hazardous to health and can lead to lung cancer. Indoor air conditions and ventilation systems strongly influence indoor radon concentrations. This paper focuses on effects of air change rate, indoor temperature and relative humidity on indoor radon concentrations in a one family Detached House in Stockholm, Sweden. In this study a heat recovery ventilation system unit was used to control the ventilation rate and a continuous radon monitor (CRM) was used to measure radon levels. FLUENT, a computational fluid dynamics (CFD) software package was used to simulate radon entry into the building and air change rate, indoor temperature and relative humidity effects using a numerical approach. The results from analytical solution, measurements and numerical simulations showed that air change rate, indoor temperature and moisture had significant effects on indoor radon concentration. Increasing air change rate reduces radon level and for a specific air change rate (in this work Ach = 0.5) there was a range of temperature and relative humidity that minimized radon levels. In this case study minimum radon levels were obtained at temperatures between 20 and 22 °C and a relative humidity of 50-60%.
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radon mitigation using heat recovery ventilation system in a swedish Detached House
WSEAS Transactions on Environment and Development, 2012Co-Authors: Keramatollah Akbari, Robert OmanAbstract:Balanced ventilation with heat recovery has strong effects on radon mitigation and energy saving in residential buildings. This new technology enables improvement of both indoor air quality and energy efficiency without sacrificing either. Reducing radon by means of forced ventilation requires an increase in outdoor supplied air (i.e. ventilation rate), which in turn can increase energy use. Energy losses in ventilation systems are inevitable, but new technologies such as heat recovery systems make it possible to recover most of this ventilation heat loss. Heat recovery ventilation systems, which recover energy from exhaust air, can significantly reduce ventilation losses, and balancing the indoor air pressure plays a positive role in the effectiveness of ventilation to reduce and mitigate radon levels and control indoor air quality. This paper describes a case study which considers the effects of a heat recovery ventilation system on the radon concentration and energy consumption in a Detached House in Stockholm, Sweden. The performance of the heat recovery ventilation system is examined with respect to radon mitigation and energy saving by measuring the radon concentration and analyzing the life cycle cost in winter. The results of the measurements and dynamic simulation showed that a heat recovery ventilation system was able to reduce the radon level from around 600 Bq.m -3 to below 100 Bq.m -3 and reduce energy loss from ventilation by 80%, equivalent to around 3500 kWh per year. The results of life cycle cost analysis used to assess total costs showed that this system is cost-effective and investment would pay for itself in 12 years. It should be noted that this saving is a representative sample, and that actual savings would be influenced by a large number of factors. IDA 4.0 Indoor Climate and Energy software was used to perform the dynamic simulations.