THERMAL PERFORMANCE OF FELT TYPE VEGETATED FACADE SYSTEMS IN A TEMPERATE CLIMATE DURING HEATING AND COOLING PERIODS

2021 ◽  
Vol 16 (4) ◽  
pp. 199-225
Author(s):  
Elif Özer Yüksel ◽  
Nil Türkeri
Keyword(s):  
Thermal Performance ◽  
Indoor Air ◽  
Test Results ◽  
Exterior Wall ◽  
Exterior Surface ◽  
Existing Building ◽  
Cooling Period ◽  
Heating And Cooling ◽  
Surface Temperatures ◽  
Air Temperatures

ABSTRACT Using vegetated facade systems (VFS) as a sustainable solution for existing and new buildings and evaluating thermal performance of these sytems are not a new concept. However, there is a gap in literature about measuring thermal performance of VFS applied on an insulated wall. Also, in the research literature, there are few studies measuring thermal performance of felt type VFS in temperate climates, and data about the thermal performance of VFS during winter periods is still scarce. Thus, the aim of the present study is to measure the thermal performance of a felt type VFS applied on a thermal insulated existing wall that us located in Kocaeli, Turkey, under Csa climate conditions during heating and cooling periods. Test results indicate that the felt type VFS acts as a shading device and has a positive contribution to the thermal performance of building walls during a cooling period. In daytime when there is a high amount of solar radiation, felt type VFS decreased exterior surface temperatures of the insulated existing wall by a maximum of 24.4°C, 32.2°C and 37.2°C, in spring, summer and fall periods, respectively. Additionally, indoor air temperatures of the vegetated facade were lower than indoor air temperatures of the reference facade with the maximum difference of 1.8°C during the cooling period. Also, test results indicate that the vegetated facade never dropped to below 0°C while exterior surface temperatures of the reference facade dropped below 0°C at nighttime in the winter period. Thus, it can be claimed that the felt type VFS behaves as a thermal buffer and enhances the thermal performance of the exterior wall of the existing building during heating periods at nighttime. As a conclusion, although differences between exterior surface temperatures of vegetated and reference walls were high, differences between interior surface temperatures of vegetated and reference walls were not meaningful. That is due to the fact that the existing building exterior wall assembly includes 5 cm thickness thermal insulation material which enhance the thermal performance of the brick wall. Finally, according to solar reflectance results, it can be claimed that vegetated facade systems have a positive effect on reducing urban heat island effect.

scholarly journals Estimation of sensible and latent heat based on measurements for non-typical large room

2019 ◽  
Vol 116 ◽  
pp. 00085
Author(s):  
Sylwia Szczęśniak ◽  
Juliusz Walaszczyk
Keyword(s):  
Latent Heat ◽  
Air Temperature ◽  
Historical Data ◽  
Operation Mode ◽  
Ventilation System ◽  
Thermal Conditions ◽  
Existing Building ◽  
Heating And Cooling ◽  
Air Temperatures ◽  
Heating And Cooling Load

The knowledge about dynamic changing heating and cooling load in existing building is essential for proper energy management. Whenever existing building is analyzed or ventilation system is going optimized, it’s essential to estimate temporary sensible and latent heat based on historical data. The basic conditions for heat calculations are quasi-stable thermal conditions. If supply air temperature significantly varies in short time, what happens very often, the calculations can give untrue results. The procedure described in this article improves usability of measured data affected by rapid supply air temperature changing. Therefore real sensible and latent heat can be calculated, what it is important for future optimization process. Specified, on the basis of varying supply and exhaust air temperatures, thermal loads range from -55.8 kW to 40.7 kW was substitute to more authentic range from -14.1 kW to 51.2 kW received from the conducted simulations. In addition, the data obtained from the simulation showed that latent heat gains were associated with the air temperature in the room, and not with the operation mode of the ventilation unit (day/night) as observed on the basis of historical data.

scholarly journals Bayesian Calibrating Educational Building Thermal Models to Hourly Indoor Air Temperature: Methodology and Case Study

2021 ◽  
Author(s):  
Danlin Hou ◽  
Chang Shu ◽  
Lili Ji ◽  
Ibrahim Galal Hassan ◽  
Liangzhu (Leon) Wang
Keyword(s):  
Thermal Performance ◽  
Indoor Air ◽  
Real Life ◽  
Calibration Procedure ◽  
Energy Performance ◽  
Uncertainty Assessment ◽  
Vulnerable Groups ◽  
Thermal Models ◽  
Air Temperatures ◽  
The One

Abstract With the increase in the frequency and duration of heatwaves and extreme temperatures, global warming becomes one of the most critical environmental issues. Heatwaves pose significant threats to human health, including related diseases and deaths, especially for vulnerable groups. Such as the one during the 2018 summer in Montreal, Canada, caused up to 53 deaths, with most lived in buildings without access to air-conditioning. Unlike building energy models that mainly focus on energy performance, building thermal models emphasizes indoor thermal performance without a mechanical system. It is required an understanding of the complex dynamic building thermal physics in which detailed building parameters need to be specified but challenging to be determined in real life. The uncertainty assessment of the parameters estimates can make the results more reliable. Therefore, in this paper, a Bayesian-based calibration procedure was presented and applied to an educational building. First, the building was modeled in EnergyPlus based on an in-site visit and related information collection. Second, a sensitivity analysis was performed to identify significant parameters affecting the errors between simulated and monitored indoor air temperatures. Then, a Meta-model was developed and used during the calibration process instead of the original EnergyPlus model to decrease the requirement of computing load and time. Subsequently, the Bayesian inference theory was employed to calibrate the model on hourly indoor air temperatures in summer. Finally, the model was validated. It is shown that the Bayesian calibration procedure not only can calibrate the model within the performance tolerance required by international building standards/codes but also predict future thermal performance with a confidence interval, which makes it more reliable.

scholarly journals The comparison of thermal comfort test results in selected traditional and modern buildings

2021 ◽  
Vol 286 ◽  
pp. 02008
Author(s):  
Natalia Krawczyk ◽  
Justyna Krakowiak
Keyword(s):  
Renewable Energy ◽  
Thermal Comfort ◽  
Indoor Air ◽  
Electricity Generation ◽  
Renewable Energy Sources ◽  
Energy Sources ◽  
Test Results ◽  
Intelligent Building ◽  
Heating And Cooling ◽  
University Of Technology

The use of renewable energy sources in buildings is more and more common (both for heating and cooling purposes, as well as electricity generation). The paper focuses on the thermal comfort tests in two buildings: the traditional one (that uses non-renewable sources of energy) and the modern intelligent building “Energis” of Kielce University of Technology. The thermal sensations of students in these two buildings have been compared based on the questionnaire survey and conclusions have been drawn regarding the differences between the feelings of thermal comfort in those two buildings. Apart from subjective feelings of the volunteers, the measurements of indoor air parameters were conducted in both buildings and have been presented in the paper.

scholarly journals In-Service Thermal and Luminous Performance Monitoring of a Refurbished Building with Solar Control Films on the Glazing System

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1388
Author(s):  
Henriqueta Teixeira ◽  
Maria da Glória Gomes ◽  
António Moret Rodrigues ◽  
Júlia Pereira
Keyword(s):  
Thermal Comfort ◽  
Thermal Performance ◽  
Performance Monitoring ◽  
Energy Use ◽  
Positive Impact ◽  
Radiation Absorption ◽  
Cooling Period ◽  
Heating And Cooling ◽  
Solar Control ◽  
Office Rooms

The global increase in energy needs and environmental awareness for a more efficient energy use have boosted building rehabilitation to decrease energy consumption. The installation of solar control films (SCFs) in buildings with large glazing façades makes it possible to reduce excessive solar gains through the glazing. The main purpose of the work is to assess, with field experimental data, the thermal and luminous performances of double-glazing units with SCFs installed in office rooms, in Lisbon. An experimental campaign was carried out simultaneously in three adjacent offices: one with a highly reflective SCF (external installation), one with a reflective SCF (internal installation) and one without an SCF. The exterior SCF showed the best thermal performance with reductions in the peak indoor air temperature of up to 6.9 and 2.3 °C during the representative days of the heating and cooling periods, respectively, increasing thermal comfort mainly during the cooling period. The interior SCF had a poorer thermal performance since it contributed to solar radiation absorption that is then emitted as heat into the indoor environment, increasing the greenhouse effect of the office. The presence of SCFs reduced the indoor illuminance levels, having a positive impact on thermal comfort and glare reduction in the cooling period.

scholarly journals Effects of Specific Parameters on Simulations of Energy Use and Air Temperatures in Offices Equipped with Radiant Heating/Cooling Panels

2019 ◽  
Vol 9 (21) ◽  
pp. 4609 ◽  
Author(s):  
Sabina Jordan ◽  
Jože Hafner ◽  
Martina Zbašnik-Senegačnik ◽  
Andraž Legat
Keyword(s):  
Simulation Model ◽  
Indoor Air ◽  
Energy Use ◽  
Small Degree ◽  
Radiant Heating ◽  
Feedback Information ◽  
Heating And Cooling ◽  
Air Temperatures ◽  
Frequency Magnitude ◽  
Real Building

When creating a simulation model to assess the performance of buildings, there is usually a lack of feedback information. Only in the case of measurements of a real building is a direct comparison of the measured values and simulated results possible. Parameter data related to users’ behavior or other events can also be obtained. Their evaluated frequency, magnitude and duration, along with boundary conditions, are crucial for the results. It is clear that none of them can be predicted very accurately. Most of them, however, are needed for computer modeling. In this paper we analyzed the well-defined TRNSYS simulation model of offices equipped with radiant ceiling panels for heating and cooling. The model was based on real case offices and was validated based on measurements for 1 year. The analysis included simulations in order to define what effect the parameters related mainly to users have on the energy use and the indoor air temperatures. The study confirmed that specific human activities influence the annual energy use to a relatively small degree and that their effects often counteract. It also confirmed the even more important fact that although small, these activities can influence the thermal comfort of users. It is believed that despite the fact that this research was based on an analysis of offices equipped with radiant ceiling panels, most of the results could be applied generally.

Thermal performance of a radiant wall heating and cooling system with pipes attached to thermally insulating bricks

2021 ◽  
pp. 111122
Author(s):  
Michal Krajčík ◽  
Martin Šimko ◽  
Ondřej Šikula ◽  
Daniel Szabó ◽  
Dušan Petráš
Keyword(s):  
Thermal Performance ◽  
Cooling System ◽  
Heating And Cooling ◽  
Wall Heating

scholarly journals Optimum Thickness of Thermal Insulation with Both Economic and Ecological Costs of Heating and Cooling

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3835
Author(s):  
Robert Dylewski ◽  
Janusz Adamczyk
Keyword(s):  
Thermal Insulation ◽  
Construction Materials ◽  
Optimum Thickness ◽  
Degree Days ◽  
Transfer Coefficients ◽  
Cooling Period ◽  
Heating And Cooling ◽  
Optimum Heat ◽  
Materials Used ◽  
Building Walls

The energy efficiency of the construction sector should be determined by the cleanliness of the environment and, thus, the health of society. The scientific aim of this article was to develop a methodology for determining the optimum thickness of thermal insulation, taking into account both economic and ecological aspects and considering both heating and cooling costs. The method takes into account the number of degree days of the heating period, as well as the number of degree days of the cooling period. Variants in terms of different types of thermal insulation, various types of construction materials for building walls, climatic zones and heat sources, were taken into consideration. In order to find the optimum thicknesses of thermal insulation, both in economic and ecological terms, a metacriterion was used. The optimum thicknesses of thermal insulation with the use of the metacriterion were obtained in the range of 0.11–0.55 m. It was observed that the values of the optimum heat transfer coefficients for economic and ecological reasons do not depend on the type of construction materials used for vertical walls. The type of applied heat source is of the greatest importance for the size of the economic and ecological benefits. The proposed mathematical model for determining the optimum thickness of thermal insulation with the use of a metacriterion is a kind of generalization of earlier models from the literature.

Assessing ventilation strategies in a school with observed indoor air problems

Facilities ◽  
2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Ulrika Uotila ◽  
Arto Saari ◽  
Juha-Matti Kalevi Junnonen ◽  
Lari Eskola
Keyword(s):  
Decision Making ◽  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Final Decision ◽  
Target Number ◽  
Content Type ◽  
Existing Building ◽  
Ventilation Strategies

Purpose Poor indoor air quality in schools is a worldwide challenge that poses health risks to pupils and teachers. A possible response to this problem is to modify ventilation. Therefore, the purpose of this paper is to pilot a process of generating alternatives for ventilation redesign, in an early project phase, for a school to be refurbished. Here, severe problems in indoor air quality have been found in the school. Design/methodology/approach Ventilation redesign is investigated in a case study of a school, in which four alternative ventilation strategies are generated and evaluated. The analysis is mainly based on the data gathered from project meetings, site visits and the documents provided by ventilation and condition assessment consultants. Findings Four potential strategies to redesign ventilation in the case school are provided for decision-making in refurbishment in the early project phase. Moreover, the research presents several features to be considered when planning the ventilation strategy of an existing school, including the risk of alterations in air pressure through structures; the target number of pupils in classrooms; implementing and operating costs; and the size of the space that ventilation equipment requires. Research limitations/implications As this study focusses on the early project phase, it provides viewpoints to assist decision-making, but the final decision requires still more accurate calculations and simulations. Originality/value This study demonstrates the decision-making process of ventilation redesign of a school with indoor air problems and provides a set of features to be considered. Hence, it may be beneficial for building owners and municipal authorities who are engaged in planning a refurbishment of an existing building.

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