Masaya Okumiya's research while affiliated with Nagoya University and other places

Publications (66)

Article
The present global trend towards decarbonization under the Paris Agreement encourages regions and economies to explore possible ways to reduce energy intensity and minimize emissions into the environment. The Asia-Pacific Economic Cooperation (APEC), which accounts for 60% of world energy demand, aims to reduce energy intensity by 45% from 2005 lev...
Article
Full-text available
Building energy consumption in the Asia-Pacific region continues to rise. It is important to understand the energy use and future trends of 21 members of Asia-Pacific Economic Cooperation (APEC) and to find more effective ways to achieve APEC's dual goals of reducing energy intensity by 45 % of 2005 levels by 2035 and doubling the share of renewabl...
Article
Full-text available
A desiccant air handling unit is one of the major types of dehumidification handling systems and requires hot water or hot air to regenerate sorption materials. If solar thermal energy is used as the heat source for regeneration, in general, a backup electrical heater, backup boiler, or combined heat and power (CHP) is installed in order to maintai...
Article
Full-text available
Desiccant air handling unit (DAHU) dehumidifies moisture in the air with adsorbent or sorbent. Hot water is necessary to regenerate them. In many buildings, for regeneration of the dehumidifier, hot water from combined heat and power (CHP) is used because it can supply hot water at stable temperature. When using fluctuating energy such as hot water...
Article
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In hot and humid summer as in Japan, dehumidification is important process for air conditioning. Desiccant air handling unit is one of the major system for dehumidification in which absorbent or sorbent absorbs moisture in the air and hot heat source is required in order to regenerate them. In order to use solar thermal energy efficiently, flexible...
Article
The facilities at university are composed of various buildings and rooms, and the multi sprit type air conditioning system is mainly used as the cooling and heating equipment. In energy conservation measures with many buildings like university facilities, improvement of efficiency to existing air conditioning equipment becomes a big issue. In recen...
Article
In hot and humid climate such as in Japan and south east Asia, dehumidification in summer is really important for air conditioning. Temperature and humidity independent control (THIC) of air conditioning system can handle sensible heat and latent heat separately, and provide good indoor environment and achieve energy conservation. Desiccant air han...
Article
This paper discusses about an examination of an energy management method for multi-sprit type air conditioner using centralized controller with a function of gas rate proportional division. The objective system is a gas engine heat pump air-conditioner installed in an agricultural research building. For energy conservation of multi-sprit type air c...
Chapter
Fragility of energy supply structure in Japan was exposed with Great East Japan Earthquake as a turning point. Then it is required to reduce consumption of fossil fuel and utilize renewable and unused energy for securing the safety of society. Also shift of energy supply from centralized system to decentralized one for improving efficiency of syste...
Article
This paper discusses about an examination on adequate capacity for multi-sprit type air conditioner using centralized controller with a function of gas rate proportional division. The objective system is a gas heat pump air-conditioner of an agricultural research building. The effect of energy saving was analyzed by LCEM tool using the estimated ac...
Article
In the present study, the cost effectiveness was examined of simultaneous implementation of seismic reinforcement and energy-saving renovation, retrofitted in wooden housing that was built before 1980. To start with, basic data on simultaneous implementation were examined. As methods that are used separately, a typical seismic reinforcement method...
Article
Changes of the energy consumption in welfare facilities before and after the Great Earthquake of East Japan were analyzed based on the investigation for development of the DECC. Both electricity and primary energy consumption in the facilities with the residential function were reduced by approximately 8% in the Tohoku region and 16% in the Kanto r...
Article
This research aims to construct a total building “commissioning” process that is currently underdeveloped in the architectural planning and design field and clarify its value through practical cases of total building commissioning at a university research facility. We organized and verified lifecycle commissioning from the predesign phase to the oc...
Article
Full-text available
In this study, a coupled analysis of computational fluid dynamics (CFD) and heating, ventilation, and air-conditioning (HVAC) system simulations was applied to a multi-split air-conditioning system in the operation phase during a power-saving period in summer. Two different forced operation schemes for the indoor units, i.e., a regular rotation con...
Article
Full-text available
System behavior analysis and performance evaluation of solid desiccant air handling unit using polymer sorbent are conducted under various operation condition in summer. In this system, solar thermal and CGS is used for regeneration coil and well water is supplied to pre- And after-coil. The system performance is determined with not only performanc...
Article
In this study, a coupled analysis of computational fluid dynamics (CFD) and heating, ventilation, and air-conditioning (HVAC) system simulations was applied to a multi-split air-conditioning system in the operation phase during a power-saving period in summer. Two different forced operation schemes for the indoor units, i.e., a regular rotation con...
Article
Because of the lack of power in Tokyo and Tohoku due to Tohoku-Pacific Ocean Earthquake that occurred on March 11, 2011, ordinance of electric power usage restrictions were triggered for the first time in 37 years. Large consumers of more than 500kW electric power contract were asked to reduce power consumption of 15%. Furthermore, since the power...
Article
Because of the lack of power in Tokyo and Tohoku due to Tohoku-Pacific Ocean Earthquake that occurred on March 11, 2011, ordinance of electric power usage restrictions were triggered for the first time in 37 years. Large consumers of more than 500kW electric power contract were asked to reduce power consumption of 15%. Furthermore, since the power...
Article
This paper presents a novel solar-ground source heat pump system (SGSHPS) designed for an office building in Beijing for heating, cooling, and producing domestic hot water. An operation strategy of the system in transition seasons is proposed to keep the heat pump off and connect ground heat exchanger (GHE) directly to the heat exchangers of fan co...
Article
In this study, a coupled analysis of computational fluid dynamics (CFD) and heating, ventilation, and air-conditioning (HVAC) system simulations was applied to a multi-split airconditioning system in the operation phase during a power-saving period in summer. In particular, the effects of two different forced operation controls for indoor units, re...
Article
In this study, we aimed to confirm whether it is possible to improve the accuracy of the estimation equations of energy consumption rate of office buildings.By the difference in the type of heat source equipment, we classified the DECC survey data of 2009 fiscal year into three categories: “the electrical type”, “the fuel-based type with boiler” an...
Article
In this study we aimed to identify characteristics of energy consumption of accommodation building by drawing on 2009 fiscal year of DECC survey data. Conducting statistical analysis on the base-load and the fluctuation-load on a national scale derived from patterns of variation in the monthly energy consumption, we obtained estimation equations fo...
Article
Authors gathered and investigated annual energy consumption of 4,194 retail facilities. The retail facilities were classified by the retail categories into department store, general merchandise store, grocery store, garment store, household merchandise store, home center, drag store, convenience-store, shopping center and specialized store. The ave...
Article
抄録 Through numerical simulation, the solar heat gain and thermal transmittance of a double-skin façade in a hot and humid climate was investigated using Indonesia’s climate condition as a case study and considering the orientation (east and west), the thickness, and the distance between glass skins. The results show that as the thickness of the gla...
Article
Full-text available
抄録 The number of commercial buildings in Japan is estimated over 10 million and these buildings are considered to emit large amounts of CO2. However, environmental load for commercial buildings has not been fully researched and those researches done in the past have focused on limited subjects or areas in Japan. This research aims to develop a nati...
Article
Full-text available
抄録 Double-skin façade is a technique covered with glasses the building exterior, it can realize energy saving as well as highly transparent façade. From these perspectives, the installation of double-skin façade for office building has increased in recent years. The design of the recent focus on life cycle assessment needs annual or seasonal perfor...
Article
抄録 This research intends to define base load and fluctuation load from the pattern of monthly changes in the energy consumption of office buildings in Japan obtained from the investigation in 2009 fiscal year, and to clarify the characteristics of energy consumption by determining estimation equations. It became possible to confirm the tendency by...
Article
A coupled analysis of CFD and HVAC system simulations was carried out to assess the mixing energy loss in an air-conditioned office room where heating and cooling operate in the perimeter and interior zones simultaneously. To evaluate the mixing energy loss, we conducted two simulations; one was the case with the airflow mixing between the perimete...
Article
This study is a part of the project that aims to construct the database for energy consumption of commercial buildings on the national scale. The purpose of this study is to obtain the basic data for energy consumption in the welfare facilities for the most of aged persons. The authors classified the buildings into two types of the residential and...
Article
The energy saving technique clearly as energy reduction quantitatively is effectual to promote an application of the technique in the design, execution and operation of the building. In this study, about some energy saving technique, we evaluated the effect quantitatively for the typical office building with system simulation. In addition, we deal...
Article
Models of double-skin facade with various outer and inner glass skin combinations, distances and orientations has been analyzed using numerical simulation. The results show that the thickness of the glass skin is important in reducing solar heat gain: as the thickness of the glass is increased, solar heat gain decreases. On the contrary, as the dis...
Article
Full-text available
This report describes the utility of coupling an energy simulation tool and computational fluid dynamics (CFD) for modelling a heating, ventilation and air-conditioning (HVAC) system, and demonstrates the application of this method in the design phase. A case study was conducted for the design phase of an air-conditioning system with an under floor...
Article
Full-text available
A coupled analysis of heating, ventilation and air-­ conditioning (HVAC) system simulation tool and computational fluid dynamics (CFD) model was carried out to assess the mixing energy loss in an air-­ conditioned room where heating and cooling operate in the perimeter and interior zones simultaneously. To evaluate the mixing energy loss, we conduc...
Article
From the viewpoint of indoor environmental control and CO2 discharge reduction, it’s necessary to evaluate the air-conditioning system in life cycle. And the system simulation is effective for evaluating an air-conditioning system. We compared “DeST” with “LCEM tool”, which are the air-conditioning system simulation program, in the characteristic,...
Article
The subject of this study is to improve the efficiency of the air-conditioning system, and to support the life cycle energy management for HVAC system of the building. And, it is considered that the HVAC system simulation tool coupling with CFD is a useful measure to realize the subject of this study. In this paper, it is described the significance...
Article
Full-text available
The objective of this study is to contribute to widespread use of earth-to-air heat exchangers by proposing a design procedure. In this paper, it is discussed the design method when an earth-to-air heat exchanger system consists of multiple pipes with a close arrangement.A numerical model for this multi-cool/heat tube system was developed and it wa...
Article
A double-skin system (double-glazed external wall) is an effective passive system that can be used to decrease solar heat gain into buildings. Detailed information on the thermal distribution of double-skin facades is necessary to design better systems that can provide thermal comfort and conserve energy. In this study, the three-dimensional therma...
Article
Full-text available
The objective of this study is to propose a prediction technique for cooling effect of dry mist, and present useful data for design / control of a dry mist system. In this paper, the cooling effect of dry mist system was verified by two dry mist systems there were actually introduced and operated. One of the verified systems is a dry mist system th...
Article
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A cooling system that sprays micro water droplets could prove useful in mitigating temperature increases in urban areas by using the heat of water evaporation, a process that consumes only small amounts of water and energy. If water mist is sprayed in a semi-outdoor area, for example, under a canopy, it could potentially improve conditions on hot d...
Article
The importance of LCEM (life cycle energy management) has been recognized from the view of life cycle energy savings for sustainable buildings. The purposes of this research are the proposal of an LCEM framework and development of prototype HVAC system simulation tools for LCEM. In this paper, the necessity of energy simulation tools for LCEM is di...
Article
Light artificial soil planted with sedum is commonly used in thin green roof units today. This paper shows the effects of the percentage of water content and some meteorological data on the evapotranspiration rate in summer. From a field measurement and multivariable analysis, the evapotranspiration rate could be well estimated in the form of a non...
Article
Green roof units consisted of sedum plants and artificial soil has been popular because of its simple and light structure. The evapotranspiration characteristics is enough complex, however, and it is not discussed yet. We conducted a long term experiment that cleared the amount of evaporation is connected with the amount of solar radiation and the...
Article
This study aims to propose a planning and design method for a residential co-generation system. This paper discuss about a gas-engine generator system. The system simulation program is developed to analyze the system behavior and the performance, and the program is verified in comparison between simulation results and experimental data. It is repre...
Article
When the several cool/heat tubes are buried under ground into proximity arrangement, heat exchange capability of the tubes is decreased from the influence of the adjoining tube. Although each tube needs sufficient distance, tubes are buried into proximity arrangement frequently, because of the restriction of space and the cost for digging. Therefor...
Conference Paper
The paper presents a tropical courtyard as a design strategy in promoting indoor air movement within a single storey dwelling. The results of a computer simulation (CFD) carried out for indoor airflow pattern reveals that wind entering from the openings of the external envelope travels through the indoor spaces and finally discharges into the sky f...
Article
Full-text available
The paper investigates the potential of a courtyard for passive cooling in a single storey high mass building in a warm humid climate. The inclusion of an internal courtyard in building design is attributed to the optimization of natural ventilation in order to minimize indoor overheating conditions. However, the efficiency of this strategy greatly...
Article
This paper presents a feasibility study of a fresh air load reduction system by using an underground double floor space. The fresh air is introduced into the double slab space and pass the opening bored through footing beam. The air is cooled by the heat exchange with inside surface of the double slab space in summer, and heated in winter. Then the...
Conference Paper
For increasing total efficiency of solar collectors, PV/T hybrid collectors are focused. A number of simulation models for the PV/T hybrid collector have been proposed, but there are few models that checked the relevance by comparison with the actual measurement. Therefore we picked up sheet-tube type hybrid collectors and measured the thermal and...
Article
This paper investigates the effects of airflow patterns and airflow rates on thermal behavior of a ventilated courtyard building in a warm humid climate. With some airflow patterns indoor air temperature can be brought to a level below the ambient, while with others the indoor air temperature may be higher than the ambient. The integration of a cou...
Conference Paper
This paper assesses the effects of indoor airflow behavior modifying the indoor air temperature on thermal comfort conditions in a residential tropical courtyard building where courtyard maintains direct contacts with outdoor environment through openings found in the envelope. Results taken from a field investigation and a computer simulation revea...
Article
The purpose of this study is to understand the performance of floor heating system using solar energy (i.e. with collector and storage tank as a heat source) by simulation method. The main points are focused on the using of solar energy, the indoor thermal environment and the energy saving performance of the system. The floor heating model was deve...
Article
In this paper, performance of three types of district heating/cooling and hot water supply system with natural and unused energy utilization were examined by using system simulation. An area zoned for both commercial and residential buildings was chosen for this study. The first system is the conventional system in which an electric driven turbo ch...
Article
A photovoltaic-thermal hybrid collector consisting of a solar panel and a collector can produce electric and thermal energy simultaneously. We made an experiment in winter and found the effect of wind velocity on the hybrid collector performance should not be ignored. The large wind velocity provides a decrease in heat gain greatly and an increase...
Article
TRNSYS was developed as a dynamic system simulation program, however, a Flat Plate Collector (FPC) model included in the standard TRNSYS library is a steady-state model. The purpose of this paper is to develop and propose a transient FPC model which takes the effect of thermal capacity into account. Firstly a conventional FPC model and two transien...
Article
This paper presents a feasibility study of a fresh air load reduction system by using an underground double floor space. The system was introduced into a real building (Aichi Children's Center in Japan) and was examined by the field measurement. Judging from the measurements during two years (summer, 1996 ~ summer, 1998), the state of the system op...
Article
In this study, the viability of annual cycle energy system -ACES- with seasonal thermal storage was examined using system simulation. The annual cycle energy utilization is basically achieved by sifting hot and cold exhaust heat by cooling and heating to winter and summer respectively. And the difference of both quantity is made up by the solar ene...
Article
The laws of scaling for unsteady-state smoke movement were derived by dimensional analysis of the governing equations (continuity, conservation of momentum and conservation of energy) and the boundary condition at the flames and the wall. Experiments were conducted in two stages, two different sizes (1:2.5)and real fire test and its reduced model (...
Article
Theoretical development and a practical design process, accompanied by easy to apply data, are presented for some practical types of water thermal storage tanks. The first part describes basic design concepts, system composition and controls, characteristics of the most popular multi-connected complete mixing tanks, and an estimation table of stora...
Article
To make the data base for desing concept of thermal and air condition of school measurement of these conditions of classroom were cassied out in winter. The type of classrooms are non-climate controlled and climate controlled which are caused sound proof. The results may be summarized as follows; (1) In the non-climate-controlled classroom used the...
Article
Mathematical estimation models were mainly developed for two types of thermal storage water tank; a temperature-stratified type and a balanced type. Regression equations between a model parameter and input conditions were derived from many experiments for the temperature-stratified tank. The model of temperature-stratified type can be modified to b...
Article
Full-text available
The purpose of this study is to establish the water mist (Dry-Mist) spraying system that improves environmental conditions in the cities. In Japan we have traditional method for cooling, which is called "Uchimizu" (fig.1) by utilizing the effect of water evaporation. This time we have developed the system which utilizes this effect more efficiently...
Article
Results of comparative study for five typical simulation programs (HASP/ACSS, EnergyPlus, DOE-2, Dest and HVACSIM+(J) are discussed using. a certain reference model of an actual building. The maximum and annual cooling and heating loads and annual energy consumption are compared. Efforts were made to make calculation conditions coincide with each o...

Citations

... The process orientation indicators are to achieve the target building energy consumption under the premise of meeting the indoor environmental parameters, by guiding the envelope performance and efficiency of the energy system [9]. The evaluation method of building energy consumption is based on primary energy consumption by constraining heating/cooling demand and energy consumption synchronously [10]. Meanwhile, the envelope performance is mainly satisfied by recommending heat transfer coefficient [11]. ...
... In China, commercial building energy monitoring platforms have been deployed in dozens of provinces and cities (e.g., Shanghai) to collect hourly/daily energy data of different end-uses in building operations [63]. In terms of building structure design, ultralow energy buildings, near-zero energy buildings, and zero-carbon buildings need to be promoted [64]. Highperformance building envelopes (e.g., colored low-emissivity films [65] and variable conductivity materials [66]) should be designed to enhance building energy efficiency and reduce emissions. ...
... The proposed air conditioning unit was able to ensure thermal and humidity comfort over 90% of the time in an arid climate, whereas only 50% to 60% comfort time share was experienced in a warm humid climate. A solar-based heat pump-assisted system was modelled by Luo et al. [31] in Taiwan, and it was found to be suitable for application in such a warm and humid climate; the results were corroborated by Ukai et al. [32] who also incorporated the effect of optimised system regulation. ...
... Developers are working really hard to minimalize the energy consumption of their developed devices; however, there are many imperfections in the actual available product catalogues, technical data, and technical support service systems, especially for the annual energy designing provided by the ventilation producers for building service and energy design engineers [10,11]. Therefore, it would be particularly significant to have measured and recorded data obtained from field studies [12,13], which may be utilized in the course of design work, and which would allow a proper estimation of the expected realizable annual energy consumption of air handling elements in the function of the temperature and relative humidity of ambient and indoor air and operating parameters [14]. ...
... In a typical AHU, chilled water in the cooling coils cools the air, and hot water (or steam) in the heating coils heats the air, in order to maintain the desired temperature of the supply [4]. The supply and return fans assist in moving the air for heat exchange, as well as circulating it in the HVAC system at the required flow rate [5]. ...
... Currently, DSF is not a new type of architectural building's element. DSF is getting more attention due to its ability especially on the decreased of energy consumption Mulyadi et al. [34], energy conservation and creates good door environment [12]. As a multifunctional facade, DSF gives positive impact to a building design and accommodating a comfortable space to stay. ...
... Then it is just conceivable that a combination of the distributed generation system and hot water floor heating (HWFH) improves energy conservation in winter. Tanaka has calculated an optimum facility capacity of its system incorporating a hot-water storage tank (Tanaka 2005). The total efficiency including building thermal performance is not clarified because the simulation program is simply developed with no consideration of building physics of heat transfer. ...
... 18 The results of this study were published in the Database for Energy Consumption of Commercial Buildings (DECC), and there are many reports on the results of analysis of energy consumption rates, etc., using this data. [19][20][21] This information is being used in consideration of energy efficiency policies, such as the revision of energy efficiency standards. ...
... In previous studies, turf and sedum were planted on rooftops and changes in the water balance and heat balance were observed [32,33]. Yoshinaga [34] reported that sedum is often used with artificial lightweight soil to minimize increases in building loads, taking advantage of sedum's resistance to parching; however, the grass and sedum conventionally used for rooftop greening retains only modest amounts of water, which constrains cooling effects [35]. ...