scholarly journals Selected Aspects of Indoor Climate in a Passive Office Building with a Thermally Activated Building System: A Case Study from Poland

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 860
Author(s):  
Piotr Michalak
Keyword(s):  
Air Temperature ◽  
Thermal Conditions ◽  
Office Building ◽  
Normal Operation ◽  
Indoor Climate ◽  
Thermally Activated ◽  
System A ◽  
Warm Sensation ◽  
Building System ◽  
Heating Energy Consumption

Modern buildings with new heating, ventilation and air conditioning (HVAC) systems offer possibility to fit parameters of the indoor environment to the occupants’ requirements. The present paper describes the results of measurements performed in an office room in the first Polish passive commercial office building during four months of normal operation. They were used to calculate parameters describing thermal comfort: vertical air temperature profile, floor surface temperature, predicted mean vote (PMV) and predicted percent of dissatisfied (PPD). Obtained results confirmed good thermal conditions in the analysed room. The average temperature of the floor’s surface varied from 20.6 °C to 26.2 °C. The average vertical air temperature, calculated for working days, was from 22.5 °C to 23.1 °C. The temperature difference between the floor and 5 cm below the ceiling was from −0.9 °C to 6.3 °C. The PMV index varied from 0.52 to 1.50 indicating ‘slightly warm’ sensation, in spite of ‘neutral’ reported by employees. Also measured cooling and heating energy consumption was presented. The performed measurements confirmed the ability of thermally activated building system (TABS) to keep good thermal conditions.

scholarly journals Thermal comfort and draught assessment in a modern open office building in Tallinn

2019 ◽  
Vol 111 ◽  
pp. 02013 ◽  
Author(s):  
Martin Kiil ◽  
Alo Mikola ◽  
Martin Thalfeldt ◽  
Jarek Kurnitski
Keyword(s):  
Thermal Comfort ◽  
Air Temperature ◽  
Energy Demand ◽  
Working Environment ◽  
Office Building ◽  
Indoor Climate ◽  
Air Velocity ◽  
Air Exchange Rate ◽  
Air Speed ◽  
Open Office

Modern office building users have high expectations about the working environment and thermal comfort, which requires the installation of complex technical systems such as combined cooling and ventilation. Room conditioning units of these systems must ensure temperature and ventilation control in a way that air velocity is low and the air temperature in acceptable range. Achieving air distribution avoiding draught is one of the key elements of a thermal comfort in modern office landscape. Higher air velocity in occupied zone is easily perceived as draught, which causes occupant dissatisfaction and complaints, as well as decrease in the productivity or effective floor space area. To reduce complaints, room air temperature setpoints or ventilation airflow rates are often modified, which may result in higher heating energy demand. In addition, excessive heating setpoint rise will not only consume more energy, but may cause health problems. Compared to cellular offices it is more difficult to ensure thermal comfort conditions in open office spaces where there are no walls for air flows. In addition, due to the higher number of employees it is more difficult to meet satisfactory conditions for everyone. The aim of this study was to evaluate thermal comfort parameters such as room air temperature, air speed and supply air temperature and how the users sense it in a modern office building in Tallinn, Estonia. Design room air temperature setpoints and air exchange rate were evaluated on open office spaces. Measured data with web-based indoor climate questionnaire was analysed. Results show which design and measured parameters make it possible to match the user comfort at all times.

scholarly journals Improving Building Energy Performance Using Dual VAV Configuration Integrated with Dedicated Outdoor Air System

Buildings ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 466
Author(s):  
Nabil Nassif ◽  
Iffat Ridwana
Keyword(s):  
Energy Consumption ◽  
Air Temperature ◽  
Energy Savings ◽  
Energy Performance ◽  
Office Building ◽  
Effective Control ◽  
Cooling Load ◽  
Outdoor Air ◽  
System A ◽  
Cooling Loads

As building systems account for almost half of the total energy consumed by the building sector to provide space heating, cooling, and ventilation, efficiently designing these systems can be the key to energy conservation in buildings. Dual VAV systems with an effective control strategy can substantially reduce the energy consumption in buildings, providing a significant scope of further research on this system configuration. This paper proposes to utilize the warm air duct of the dual VAV system as a dedicated outdoor air (DOA) unit when no heating is required, which allows the cooling load to be effectively distributed between two ducts. A specific control sequence is proposed with different supply air temperature reset strategies to estimate the heating, cooling loads, and fan power energy consumption of the proposed system. A simple two-zone office building is taken as a preliminary case study to simulate the airflow rates and fan power of a single duct VAV and proposed dual VAV systems to illustrate the concept. Finally, a larger multi-zone office building is simulated to measure the annual heating, cooling loads, and fan power energy and compare the energy savings among the systems. The results show significant fan power reduction ranging from 1.7 to 9% and notable heating energy reduction up to 76.5% with a small amount of cooling load reduction varying from 0.76 to 2.56% depending on the different locations for the proposed dual VAV systems. Further energy savings from different supply air temperature reset strategies demonstrate the opportunity of employing them according to climates and case studies. The proposed dual VAV system proves to have the potential to be adapted in buildings for the purpose of sustainability and energy savings.

scholarly journals Utilization of Thermally Activated Building System with Horizontal Ground Heat Exchanger Considering the Weather Conditions

Energies ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7927
Author(s):  
Woong June Chung ◽  
Sang Hoon Park
Keyword(s):  
Air Temperature ◽  
Peak Load ◽  
Weather Conditions ◽  
Ground Temperature ◽  
Outdoor Air ◽  
Ground Temperatures ◽  
Thermally Activated ◽  
Ground Heat Exchangers ◽  
Building System ◽  
Energy Simulations

The thermally activated building system (TABS) can reduce the peak load by integrating with the ground heat exchangers. When integrated, the cost of groundwork and stability of the ground temperature would counteract because the weather conditions would influence the ground temperature in shallow depth. However, previous studies on TABS assumed constant ground temperatures such as average outdoor air temperature. In this study, ground temperatures in different depths are simulated for their detailed investigations, and simulated results of ground temperature were applied to building energy simulations for observing the load-handled ratio (LHR), representing the peak load reduction by TABS evaluated in various weather conditions. Simulation results of ground temperatures from 1 m to 39 m depths show that the temperature stabilized at 2 m to 11 m depths depending on the characteristics of the outdoor air temperature. LHR increased as the ground depth increased because the ground temperature at shallow depths increased during peak hours. Ground depths of 8 m were found ideal for maintaining consistent LHR for all weather conditions. Detailed observation of ground temperature and its effect on LHR in various weather conditions can help system engineers design and operate the TABS with the ground system.

ON THE THERMAL REGIME OF THE SURFACE AIR LAYER IN THE DEBED RIVER BASIN (ARMENIA)

2021 ◽  
Vol 1 (1) ◽  
pp. 31-44
Author(s):  
MARGARYAN V.G. ◽  
Keyword(s):  
River Basin ◽  
Air Temperature ◽  
Thermal Regime ◽  
Time Course ◽  
Temporal Distribution ◽  
Thermal Conditions ◽  
High Mountain ◽  
Air Temperatures ◽  
Using Data ◽  
Surface Air Layer

The features of the thermal regime of the surface air layer in the Debed river basin are considered. A statistical analysis of the average annual and average seasonal values of air temperature from 1964 to 2018 was carried out, two periods were identified, their time course was shown. The analysis was carried out using data from six meteorological stations representing the lowland, mountain and high-mountain climatic zones of the Debed river basin. A correlation was obtained between the absolute altitude and the monthly average values of air temperature for January and July, which can be used to assess the thermal conditions of unexplored or poorly studied territories and for cartography. The time course of average values of air temperatures for the seasonal period has been studied. Analysis of trend lines of temporal changes in air temperatures shows that in all situations on the territory of the basin as a whole, there is a tendency of temperature growth. Moreover, with a range of interannual fluctuations, a break in the course of temperatures in the early to mid 1990 is clearly visible, after which their significant increase began. It turned out that a significant increase in seasonal temperatures is observed especially over the period 1993-2018, which means that the annual warming after the mid 1990 occurred primarily due to summer and spring seasons. The regular dynamics indicates that in the studied area in terms of temperatures, a tendency of softening winters, a decrease in the water content of rivers, aridization of the climate. The results obtained can be used to assess the regularities of the spatial-temporal distribution of the temperature of the study area, to clarify the thermal balance, for the rational use of heat resources, as well as in the development of strategic programs for longterm analysis.

scholarly journals Basic Passive Side-Day lighting Considerations for High Rise office Building

2020 ◽  
Vol 9 (5) ◽  
pp. 78-87
Keyword(s):  
Energy Consumption ◽  
Construction Industry ◽  
Positive Impact ◽  
Building Design ◽  
High Energy ◽  
Office Building ◽  
High Rise ◽  
Design Considerations ◽  
System A ◽  
Modern Era

High rise office building design is one of the essential buildings in construction industry due to the limited space especially in the urban area. After home, a high rise office building is an important space for human in modern era. Due to the issue of high energy consumption especially inefficient artificial light strategy, side-day lighting becomes the best solution for a high rise office building design. Despite providing efficient energy consumption, side-day lighting creates a positive impact to the worker as well as the office's indoor environment. Hence, this paper aims to explore the basic passive side-day lighting considerations that educate people especially for those who are involved in the building construction industry. Beside, this paper focuses on the passive design considerations due to the various advantages that not involved especially with complex electrical and mechanical system. A systematic literature review is the main methodology for this paper to identify the basic passive side-day lighting considerations for a high rise office building design. Base on this research, it revealed that eight elements for building design considerations should be applied to provide a better day lighting impact for a high rise office building design. Considerations for non-building design aspects should also need to be applied since those aspects contribute to produce a better day lighting impact for a high rise office building design.

scholarly journals Altitude and Canopy Cover Effects on Air Temperature in a Mountainous Region of Ionian Islands, Greece

2018 ◽  
Vol 13 (3) ◽  
pp. 292-298
Author(s):  
ATHANASIOS KAMOUTSIS ◽  
KOSTAS CHRONOPOULOS ◽  
ARISTIDIS MATSOUKIS
Keyword(s):  
Air Temperature ◽  
Canopy Cover ◽  
Decisive Role ◽  
Thermal Conditions ◽  
Special Importance ◽  
Mean Values ◽  
Ionian Islands ◽  
Hiking Trails ◽  
Forested Areas ◽  
Of Greece

Topography and canopy play a decisive role on air temperature (T) conditions in forested areas. Air temperature is a crucial factor in decision making process for the development of these areas. To our knowledge, there is no information regarding the effect of topography along with canopy cover (Pc) on thermal conditions of a vulnerable mountainous forested region of Greece, Mount (Mt) Aenos in the island of Cephalonia, Ionian Islands, Greece. Therefore, the purpose of our work is the investigation of the aforementioned parameters, especially the effect of altitude (alt) and Pc on T of Mt Aenos. Mean values for maximum air temperature (Tx) and Pc were estimated for twelve sites at various alts in Mt Aenos during the period May-October of three consecutive years (2011-2013). The analysis of the results showed that Tx was related to alt and Pc. Altitude has a greater effect on T in relation to Pc. When examining same or similar alts, an increase of Pc up to 51% resulted in a significant decrease of Tx (p<0.05) up to 3.6 °C. Our findings could be taken into account in planning the construction of hiking trails for recreational activities in Mt Aenos, and, in general, in mountainous forest areas of special importance.

scholarly journals Decorative values of selected cultivars of climbing roses (Rosa L.) with regard to thermal conditions

2012 ◽  
Vol 60 (1) ◽  
pp. 135-142
Author(s):  
Zofia Włodarczyk ◽  
Agnieszka Perzanowska
Keyword(s):  
High Temperatures ◽  
Air Temperature ◽  
Thermal Conditions ◽  
Temperature Pattern ◽  
Flowering Period ◽  
Green Areas

In the years 2004-2006 in Kraków, phenological observations of climbing roses were conducted in order to determine the length and dates of their flowering period. The diameters of their flowers were also compared. Eight flowering repeating cultivars were selected for the experiment: 'Climbing Souvenir de la Malmaison', 'Dortmund', 'Golden Showers', 'Goldstern', 'New Dawn', 'Parade', 'Sympathie' and 'White New Dawn'. During the studies, the shrub roses were not artificially watered in order to create conditions similar to those prevailing in public green areas. It was observed that irrespective of the air temperature pattern in a given year, the studied cultivars did not bloom before 15 June. In 2006 high temperatures (above 20<sup>o</sup>C), which continued throughout the whole flowering period, caused its shortening, and the interval between the first and the next flowering in the season lasted longer than in the previous years. In the years 2004-2006, the cultivar 'New Dawn' bloomed the longest. In 2005 the studied cultivars produced larger flowers than the next year. The cultivars 'Dortmund' and 'White New Dawn' were characterised by the smallest diameter of flowers, whereas 'Climbing Souvenir de la Malmaison', 'Golden Showers' and 'Parade' were marked by the largest diameter.

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