Occupant-centric controls(OcC)is an indoor climate control approach whereby occupant feedback is used in the sequence of operation of building energy systems.While OcC has been used in a wide range of building applica...Occupant-centric controls(OcC)is an indoor climate control approach whereby occupant feedback is used in the sequence of operation of building energy systems.While OcC has been used in a wide range of building applications,an OcC category that has received considerable research interest is learning occupants'thermal preferences through their thermostat interactions and adapting temperature setpoints accordingly.Many recent studies used reinforcement learning(RL)as an agent for OcC to optimize energy use and occupant comfort.These studies depended on predicted mean vote(PMV)models or constant comfort ranges to represent comfort,while only few of them used thermostat interactions.This paper addresses this gap by introducing a new off-policy reinforcement learning(RL)algorithm that imitates the occupant behaviour by utilizing unsolicited occupant thermostat overrides.The algorithm is tested with a number of synthetically generated occupant behaviour models implemented via the Python APl of EnergyPlus.The simulation results indicate that the RL algorithm could rapidly learn preferences for all tested occupant behaviour scenarios with minimal exploration events.While substantial energy savings were observed with most occupant scenarios,the impact on the energy savings varied depending on occupants'preferences and thermostat use behaviour stochasticity.展开更多
Severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),the cause of the current coronavirus disease 2019(COVID-19)pandemic,is evolving.Thus,the risk of airborne transmission in confined spaces may be higher,and c...Severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),the cause of the current coronavirus disease 2019(COVID-19)pandemic,is evolving.Thus,the risk of airborne transmission in confined spaces may be higher,and corresponding precautions should be re-appraised.Here,we obtained the quantum generation rate(q)value of three SARS-CoV-2 variants(Alpha,Delta,and Omicron)for the Wells-Riley equation with a reproductive number-based fitted approach and estimated the association between the infection probability and ventilation rates.The q value was 89–165 h^(−1)for Alpha variant,312–935 h^(−1)for Delta variant,and 725–2,345 h^(−1)for Omicron variant.The ventilation rates increased to ensure an infection probability of less than 1%,and were 8,000–14,000 m^(3)h^(−1),26,000–80,000 m^(3)h^(−1),and 64,000–250,000 m^(3)h^(−1)per infector for the Alpha,Delta,and Omicron variants,respectively.If the infector and susceptible person wore N95 masks,the required ventilation rates decreased to about 1/100 of the values required without masks,which can be achieved in most typical scenarios.An air purifier was ineffective for reducing transmission when used in scenarios without masks.Preventing prolonged exposure time in confined spaces remains critical in reducing the risk of airborne transmission for highly contagious SARS-CoV-2 variants.展开更多
To achieve required indoor air quality,fresh air supply in buildings should meet relevant standards and regulations.However,the handling of fresh air introduced a cooling load that takes up a large portion of building...To achieve required indoor air quality,fresh air supply in buildings should meet relevant standards and regulations.However,the handling of fresh air introduced a cooling load that takes up a large portion of building energy consumption,especially in tropical and subtropical areas.A proper way should be employed to reduce the cooling load of fresh air.Radiative sky cooling,which is the process that an object cools itself by emitting thermal radiation to outer space without any energy input,is a cost-effective and eco-friendly technology.In this work,a fresh air pre-cooling system using radiative sky cooling is proposed to reduce fresh air cooling load.The system,consisting of filters,a radiative air-cooling system,an air handling unit(AHU),fans,etc.,is installed on the rooftop of the modeled building.Six cities in low-latitude areas are selected and investigated.Results show that with the radiative air-cooling system installed,annual cooling energy consumption of the modeled building can be reduced by around 10%in most cities.For arid areas,e.g.,Abu Dhabi,the system has even better performance with 19.34%annual cooling energy saving.展开更多
Background:Atopic dermatitis(AD)is a distressing disease associated with pruritus and sleep disturbance.It is not known how well these symptoms correlate with the extent and intensity of eczematous involvement.We eval...Background:Atopic dermatitis(AD)is a distressing disease associated with pruritus and sleep disturbance.It is not known how well these symptoms correlate with the extent and intensity of eczematous involvement.We evaluated whether:(i)the level of sleep loss correlates with pruritus and(ii)the level of pruritus correlates with the extent or severity of AD in children according to the SCORing Atopic Dermatitis(SCORAD)index.Method:Patients with AD younger than 18 years old were recruited from the pediatric dermatology clinic of a university teaching hospital,and AD severity was evaluated by the SCORAD index.Results:One hundred and eighty-two Chinese children with AD(107 boys and 75 girls)[mean(SD)age of 9.6(4.2)years] were recruited.Their mean(SD)overall SCORAD was 30.1(19.2).Sleep loss was strongly correlated with pruritus(r=0.57,P < 0.001).However,the two subjective symptoms were only weakly correlated with the objective signs(extent and intensity)of AD.The correlations between pruritus and extent and intensity were 0.42(P < 0.001)and 0.38(P < 0.001),respectively,and the correlations between sleep loss and extent and intensity were 0.38(P < 0.001)and 0.34(P < 0.001),respectively.Conclusion:We speculate that the lack of a better correlation was either because pruritus and sleep loss as reported by parents were imprecise,or that mechanisms other than disease extent or severity are responsible for the pathogenesis of these subjective symptoms.展开更多
文摘Occupant-centric controls(OcC)is an indoor climate control approach whereby occupant feedback is used in the sequence of operation of building energy systems.While OcC has been used in a wide range of building applications,an OcC category that has received considerable research interest is learning occupants'thermal preferences through their thermostat interactions and adapting temperature setpoints accordingly.Many recent studies used reinforcement learning(RL)as an agent for OcC to optimize energy use and occupant comfort.These studies depended on predicted mean vote(PMV)models or constant comfort ranges to represent comfort,while only few of them used thermostat interactions.This paper addresses this gap by introducing a new off-policy reinforcement learning(RL)algorithm that imitates the occupant behaviour by utilizing unsolicited occupant thermostat overrides.The algorithm is tested with a number of synthetically generated occupant behaviour models implemented via the Python APl of EnergyPlus.The simulation results indicate that the RL algorithm could rapidly learn preferences for all tested occupant behaviour scenarios with minimal exploration events.While substantial energy savings were observed with most occupant scenarios,the impact on the energy savings varied depending on occupants'preferences and thermostat use behaviour stochasticity.
基金We are grateful to Miss Ye Wang and the support provided by the Tsinghua University Spring Breeze Fund(2020Z99CFZ025).
文摘Severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),the cause of the current coronavirus disease 2019(COVID-19)pandemic,is evolving.Thus,the risk of airborne transmission in confined spaces may be higher,and corresponding precautions should be re-appraised.Here,we obtained the quantum generation rate(q)value of three SARS-CoV-2 variants(Alpha,Delta,and Omicron)for the Wells-Riley equation with a reproductive number-based fitted approach and estimated the association between the infection probability and ventilation rates.The q value was 89–165 h^(−1)for Alpha variant,312–935 h^(−1)for Delta variant,and 725–2,345 h^(−1)for Omicron variant.The ventilation rates increased to ensure an infection probability of less than 1%,and were 8,000–14,000 m^(3)h^(−1),26,000–80,000 m^(3)h^(−1),and 64,000–250,000 m^(3)h^(−1)per infector for the Alpha,Delta,and Omicron variants,respectively.If the infector and susceptible person wore N95 masks,the required ventilation rates decreased to about 1/100 of the values required without masks,which can be achieved in most typical scenarios.An air purifier was ineffective for reducing transmission when used in scenarios without masks.Preventing prolonged exposure time in confined spaces remains critical in reducing the risk of airborne transmission for highly contagious SARS-CoV-2 variants.
基金support from the Natural Science Foundation of Jiangsu Province,China(Grant No.BK20200373).
文摘To achieve required indoor air quality,fresh air supply in buildings should meet relevant standards and regulations.However,the handling of fresh air introduced a cooling load that takes up a large portion of building energy consumption,especially in tropical and subtropical areas.A proper way should be employed to reduce the cooling load of fresh air.Radiative sky cooling,which is the process that an object cools itself by emitting thermal radiation to outer space without any energy input,is a cost-effective and eco-friendly technology.In this work,a fresh air pre-cooling system using radiative sky cooling is proposed to reduce fresh air cooling load.The system,consisting of filters,a radiative air-cooling system,an air handling unit(AHU),fans,etc.,is installed on the rooftop of the modeled building.Six cities in low-latitude areas are selected and investigated.Results show that with the radiative air-cooling system installed,annual cooling energy consumption of the modeled building can be reduced by around 10%in most cities.For arid areas,e.g.,Abu Dhabi,the system has even better performance with 19.34%annual cooling energy saving.
文摘Background:Atopic dermatitis(AD)is a distressing disease associated with pruritus and sleep disturbance.It is not known how well these symptoms correlate with the extent and intensity of eczematous involvement.We evaluated whether:(i)the level of sleep loss correlates with pruritus and(ii)the level of pruritus correlates with the extent or severity of AD in children according to the SCORing Atopic Dermatitis(SCORAD)index.Method:Patients with AD younger than 18 years old were recruited from the pediatric dermatology clinic of a university teaching hospital,and AD severity was evaluated by the SCORAD index.Results:One hundred and eighty-two Chinese children with AD(107 boys and 75 girls)[mean(SD)age of 9.6(4.2)years] were recruited.Their mean(SD)overall SCORAD was 30.1(19.2).Sleep loss was strongly correlated with pruritus(r=0.57,P < 0.001).However,the two subjective symptoms were only weakly correlated with the objective signs(extent and intensity)of AD.The correlations between pruritus and extent and intensity were 0.42(P < 0.001)and 0.38(P < 0.001),respectively,and the correlations between sleep loss and extent and intensity were 0.38(P < 0.001)and 0.34(P < 0.001),respectively.Conclusion:We speculate that the lack of a better correlation was either because pruritus and sleep loss as reported by parents were imprecise,or that mechanisms other than disease extent or severity are responsible for the pathogenesis of these subjective symptoms.
