scholarly journals Energy Use and Perceived Indoor Environment in a Swedish Multifamily Building before and after Major Renovation

2018 ◽  
Vol 10 (3) ◽  
pp. 766 ◽  
Author(s):  
Lina La Fleur ◽  
Patrik Rohdin ◽  
Bahram Moshfegh
Keyword(s):  
Energy Efficiency ◽  
Thermal Comfort ◽  
Indoor Environment ◽  
Energy Use ◽  
Ventilation System ◽  
Heating Season ◽  
Indoor Temperature ◽  
Exhaust Ventilation ◽  
Heat Demand ◽  
Before And After

Improved energy efficiency in the building sector is a central goal in the European Union and renovation of buildings can significantly improve both energy efficiency and indoor environment. This paper studies the perception of indoor environment, modelled indoor climate and heat demand in a building before and after major renovation. The building was constructed in 1961 and renovated in 2014. Insulation of the façade and attic and new windows reduced average U-value from 0.54 to 0.29 W/m2·K. A supply and exhaust ventilation system with heat recovery replaced the old exhaust ventilation. Heat demand was reduced by 44% and maximum supplied heating power was reduced by 38.5%. An on-site questionnaire indicates that perceived thermal comfort improved after the renovation, and the predicted percentage dissatisfied is reduced from 23% to 14% during the heating season. Overall experience with indoor environment is improved. A sensitivity analysis indicates that there is a compromise between thermal comfort and energy use in relation to window solar heat gain, internal heat generation and indoor temperature set point. Higher heat gains, although reducing energy use, can cause problems with high indoor temperatures, and higher indoor temperature might increase thermal comfort during heating season but significantly increases energy use.

scholarly journals Spatial and Behavioral Thermal Adaptation in Net Zero Energy Buildings: An Exploratory Investigation

2020 ◽  
Vol 12 (19) ◽  
pp. 7961 ◽  
Author(s):  
Shady Attia
Keyword(s):  
Energy Efficiency ◽  
Thermal Comfort ◽  
Energy Use ◽  
Thermal Adaptation ◽  
Building Energy ◽  
Building Energy Efficiency ◽  
Zero Energy ◽  
Net Zero Energy ◽  
Net Zero ◽  
Energy Efficiency Standards

Climate responsive design can amplify the positive environmental effects necessary for human habitation and constructively engage and reduce the energy use of existing buildings. This paper aims to assess the role of the thermal adaptation design strategy on thermal comfort perception, occupant behavior, and building energy use in twelve high-performance Belgian households. Thermal adaptation involves thermal zoning and behavioral adaptation to achieve thermal comfort and reduce energy use in homes. Based on quantitative and qualitative fieldwork and in-depth interviews conducted in Brussels, the paper provides insights on the impact of using mechanical systems in twelve newly renovated nearly- and net-zero energy households. The article calls for embracing thermal adaptation as a crucial design principle in future energy efficiency standards and codes. Results confirm the rebound effect in nearly zero energy buildings and the limitation of the current building energy efficiency standards. The paper offers a fresh perspective to the field of building energy efficiency that will appeal to researchers and architects, as well as policymakers.

METHOD OF SELECTION AND CALCULATION DEVICES AIR CLEANING FROM CONDENSED AEROSOLS

2016 ◽  
Vol 6 (2) ◽  
pp. 14-18
Author(s):  
Denis N. VATUZOV ◽  
Svetlana M. PURING
Keyword(s):  
Energy Efficiency ◽  
Ventilation System ◽  
Design Parameters ◽  
Local Exhaust Ventilation ◽  
Improve Energy Efficiency ◽  
Air Cleaning ◽  
Exhaust Ventilation ◽  
Recovery System ◽  
Degree Of Purification ◽  
Ventilation Management

This article defines the options to improve the efficiency of local exhaust ventilation systems by incorporating into the circuit from the air cleaning devices droplet aerosol. Schemes connecting cleaning apparatus in ventilation management system are worked out. In the first embodiment, the placement aerozoleulovitelya purified ventilation air is discharged directly to the atmosphere, in the second embodiment, the cleaned air is used in the recovery system, which is removed after the street. The feasibility of using the heat exchanger in the scheme is justified by comparing the technical and economic options and the need to improve energy efficiency. The method of selection and calculation of air cleaning devices from droplet sprays, on the basis of which it is possible to determine the design parameters of the system, to evaluate the amount of captured material, and choose the most appropriate in each case unit, focusing on the desired performance of the ventilation system, the necessary degree of purification and the area for mounting the device.

scholarly journals Development of a Natural Soil Depressurization System Sizing Tool

2021 ◽  
Vol 2069 (1) ◽  
pp. 012185
Author(s):  
Marc Abadie ◽  
Zaid Romani ◽  
Michel Burlot ◽  
Jérôme Nicolle ◽  
Pierre Peigné ◽  
...  
Keyword(s):  
Indoor Environment ◽  
Ventilation System ◽  
Weather Conditions ◽  
Natural Soil ◽  
Heating Season ◽  
Thermal Transfer ◽  
Volatile Organic ◽  
Test House ◽  
Frame Work ◽  
One Year

Abstract This paper presents a summary of the main developments and results achieved in the frame-work of the French research project called EVAL-SDS. This project aims to analyse the performance of Natural, i.e. without use of fan for extraction, Soil Depressurization Systems (NSDS) to protect the built indoor environment from soil gaseous pollutant (Radon, Volatile Organic Compounds…). In this paper, the aeraulic performance of NSDS is studied i.e. its capacity to extract air from the ground to protect building’s occupants. To this end, we first performed measurements of airflow rates extracted by a NSDS integrated in a test-house during one year. Those data include various weather conditions (stack effect, wind) for several key parameters (wind extractor type, slab air permeability and basement pressure). Then, a dedicated calculation tool has been developed and validated against the experimental results. This numerical model has been used to evaluate the NSDS performance in France for different building heights and ventilation systems. The results show that NSDS succeed in creating a negative pressure under the building slab most of the time and that the extracted airflow rates can be enhanced by better design of wind extractor, association with mechanical insufflating ventilation system and thermal transfer from the building during the heating season.

scholarly journals Indoor climate and energy performance in nearly zero energy day care centers and school buildings

2019 ◽  
Vol 111 ◽  
pp. 02003 ◽  
Author(s):  
Kaiser Ahmed ◽  
Kalle Kuusk ◽  
Henrik Heininen ◽  
Endrik Arumägi ◽  
Targo Kalamees ◽  
...  
Keyword(s):  
Energy Use ◽  
Ventilation System ◽  
Energy Performance ◽  
Physical Parameters ◽  
Airflow Rate ◽  
Full Time ◽  
Indoor Climate ◽  
Indoor Temperature ◽  
Measured Energy ◽  
Time Operation

This study presents the assessment of actual indoor climate condition and energy performance in eight NZEB school and daycare centers of NERO H2020 project. Physical parameters such as indoor temperature, relative humidity, CO2, airflow rate and temperature were measured during heating and cooling seasons, in parallel with an occupants’ questionnaires survey. Besides, calculated and measured energy data was collected from energy performance certificates and energy bills. Thermal comfort and IAQ were assessed based on categories in EN15251 standard with color footprints. Results showed that all the buildings had good or excellent indoor climate during the heating season. However, a large percentage of occupied hours were categorized as category IV during the cooling season, which mainly occurred due to too low indoor temperature caused by the low outdoor temperature during the measurement period. Also, all buildings achieved low CO2 levels. Moreover, the conducted questionaries’ survey showed good correlation with measured results for all buildings except in one building, which had odor and noise problems. In contrast, the measured energy use in 5 buildings out of 7 was increased by factor 2.1-3.0 compared to calculated annual energy use due to a full-time operation of the ventilation system and presence of hot kitchens.

scholarly journals The Influence of Energy Renovation on the Change of Indoor Temperature and Energy Use

Energies ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 3179 ◽  
Author(s):  
Anti Hamburg ◽  
Targo Kalamees
Keyword(s):  
Energy Efficiency ◽  
Energy Consumption ◽  
Energy Use ◽  
Primary Energy ◽  
Hot Water ◽  
Indoor Temperature ◽  
Research Issues ◽  
Apartment Buildings ◽  
Electricity Use ◽  
Heating Energy Consumption

The aim of the renovation of apartment buildings is to lower the energy consumption of those buildings, mainly the heating energy consumption. There are few analyses regarding those other energy consumptions which are also related to the primary energy need for calculating the energy efficiency class, including the primary energy need of calculated heating, domestic hot water (DHW), and household electricity. Indoor temperature is directly connected with heating energy consumption, but it is not known yet how much it will change after renovation. One of the research issues relates to the change of electricity and DHW usage after renovation and to the question of whether this change is related to the users’ behavior or to changes to technical solutions. Thirty-five renovated apartment buildings have been analyzed in this study, where the data of indoor temperature, airflow, and energy consumption for DHW with and without circulation and electricity use in apartments and common rooms has been measured. During research, it turned out that the usage of DHW without circulation and the usage of household electricity do not change after renovation. Yet there is a major increase in indoor temperature and DHW energy use in buildings that did not have circulation before the renovation. In addition, a small increase in the use of electricity in common areas was discovered. This study will offer changes in calculations for the energy efficiency number.

scholarly journals Increasing the efficiency of split type air conditioners/heat pumps by using ventilating exhaust air

2019 ◽  
Vol 100 ◽  
pp. 00006 ◽  
Author(s):  
Wojciech Cepiński ◽  
Paweł Szałański
Keyword(s):  
Energy Efficiency ◽  
Heat Exchanger ◽  
Ventilation System ◽  
Electricity Consumption ◽  
Heat Pumps ◽  
Design Solution ◽  
Simple Design ◽  
Air Conditioner ◽  
Air Conditioners ◽  
Heat Demand

The article presents the possibility of using exhaust air from ventilation system to increase the efficiency (SCOP, COP, SEER and EER) of commonly used air conditioners with the function of a heat pump. These types of devices are very popular both in residential and in public buildings. The topic discussed in the article is very important, because the widespread increase of the energy efficiency of these devices significantly influences national electricity consumption. The possibility of increasing their efficiency by directing the exhaust air from the ventilation system to the heat exchanger of the air conditioner outdoor unit has been analysed. It has been shown that the use of the simple design solution described in the article allows for a significant increase of the efficiency of these devices (seasonal efficiency even up to 35% at 100% share of exhaust air), reducing the energy consumption and increasing their capacity and operation range. By increasing the share of exhaust air it is possible to ensure year-round operation of the device and even 100% coverage of heat demand.

scholarly journals Abatement of the Increases in Cooling Energy Use during a Period of Intense Heat by a Network-Based Adaptive Controller

2021 ◽  
Vol 13 (3) ◽  
pp. 1353 ◽  
Author(s):  
Jonghoon Ahn
Keyword(s):  
Energy Efficiency ◽  
Thermal Comfort ◽  
Energy Use ◽  
Deterministic Model ◽  
Thermal Conditions ◽  
Adaptive Controller ◽  
High Energy ◽  
Comfort Level ◽  
Indoor Environmental Quality ◽  
Comfort Indices

Various methods to control thermal conditions of building spaces have been developed to investigate their performances of energy use and thermal comfort in the system levels. However, the high control precision used in several studies dealing with data-driven methods may cause energy increases and the high energy efficiency may be disadvantageous for maintaining indoor environmental quality. This study proposes a model that optimizes the supply air condition to effectively reach the setting values by two-way controls of the supply air conditions. In such a process, if the results of the thermal comfort level are outside the range of the initial setting values, an adaptive model starts to work to send additional signals to adjust the set-point temperature. In order to assess its efficiency, the conventional thermostat model and fuzzy deterministic model are adopted as comparators. Comparing the results of the proposed network-based model with conventional control models, an improved control performance from 15.5% to 29.3% in thermal comfort indices was identified, as well as an over 30% improvement in energy efficiency. As a consequence, the network-based adaptive control rule supervising thermal comfort indices properly operates to abate increases in its energy use without compromising its thermal comfort. This performance can be significant in places where many spaces are woven at high density, and in situations where better thermal comfort can increase users’ workability and productivity.

Analysis of hygrothermal parameters in Finnish and Lithuanian multi-family buildings before and after energy retrofits

2018 ◽  
Vol 42 (4) ◽  
pp. 441-457 ◽  
Author(s):  
Virpi Leivo ◽  
Mihkel Kiviste ◽  
Anu Aaltonen ◽  
Tadas Prasauskas ◽  
Dainius Martuzevicius ◽  
...  
Keyword(s):  
Energy Efficiency ◽  
Measurement Data ◽  
Building Envelope ◽  
The Other ◽  
Data Logging ◽  
Indoor Temperature ◽  
Opposite Trend ◽  
Before And After ◽  
Weather Stations ◽  
Occupied Zone

This study focuses on analyzing temperature- and moisture-related parameters based on data from 45 Finnish and 20 Lithuanian multi-family buildings. The data consist of two rounds of 2-month data-logging (1-h interval) of indoor temperature and relative humidity at two locations: one representing average occupied zone and the other one nearby the coldest spot of the building envelope. Between the two rounds of data-logging, 37 buildings from Finland and 15 buildings from Lithuania underwent retrofits, aiming to improve their energy efficiency. Measurement data were coupled with outdoor data from national weather stations, based on which a temperature factor ( fc) and excess indoor moisture content (Δ v) were calculated. Based on the results, fc was significantly higher in Lithuanian case buildings after the retrofits, whereas no significant differences were observed in Finnish buildings. In addition, Δ v was significantly lower in Finnish case buildings after retrofits, whereas an opposite trend was seen in the Lithuanian buildings.

scholarly journals Predictive Optimization of the Heat Demand in Buildings at the City Level

2019 ◽  
Vol 9 (10) ◽  
pp. 1994
Author(s):  
Petri Hietaharju ◽  
Mika Ruusunen ◽  
Kauko Leiviskä ◽  
Marko Paavola
Keyword(s):  
Energy Efficiency ◽  
District Heating ◽  
Short Term ◽  
Indoor Temperature ◽  
Improve Energy Efficiency ◽  
Apartment Buildings ◽  
Heat Demand ◽  
Demand Models ◽  
The City ◽  
Modelling Approach

Easily adaptable indoor temperature and heat demand models were applied in the predictive optimization of the heat demand at the city level to improve energy efficiency in heating. Real measured district heating data from 201 large buildings, including apartment buildings, schools and commercial, public, and office buildings, was utilized. Indoor temperature and heat demand of all 201 individual buildings were modelled and the models were applied in the optimization utilizing two different optimization strategies. Results demonstrate that the applied modelling approach enables the utilization of buildings as short-term heat storages in the optimization of the heat demand leading to significant improvements in energy efficiency both at the city level and in individual buildings.

scholarly journals A PCM based cooling system for office buildings: a state of the art review

2019 ◽  
Vol 111 ◽  
pp. 01026
Author(s):  
Evdoxia Paroutoglou ◽  
Alireza Afshari ◽  
Niels Chr. Bergsøe ◽  
Peter Fojan ◽  
Göran Hultmark
Keyword(s):  
Renewable Energy ◽  
Energy Storage ◽  
Thermal Comfort ◽  
Energy Use ◽  
State Of The Art ◽  
Cooling System ◽  
Renewable Energy Sources ◽  
Ventilation System ◽  
High Energy ◽  
Cooling Systems

Cooling of air in buildings has a significant effect on thermal comfort and, consequently, productivity of office occupants. This study presents a state of the art review of energy efficient cooling systems that will provide occupants in buildings with satisfying thermal comfort. Using high-temperature cooling systems combined with renewable energy sources increases the energy efficiency in buildings. Latent heat thermal energy storage (LHTES) using Phase Change Materials (PCM) is a renewable energy source implemented in space cooling applications due to its high energy storage density. Since the share of commercial buildings in need of cooling is increasing, there is a need for developing new technical solutions in order to reduce the energy use without compromising thermal comfort. To this end, a proposed ventilation system, preliminarily analyzed in this paper, is expected to reduce further the energy use. The ventilation system is composed of an air handling unit, a 2-pipe active chilled beam system, and a cooling system including a LHTES using PCM. Few researchers have investigated chilled water air-conditioning systems that integrate a LHTES using PCM. In this review, function characteristics, possibilities and limitations of existing systems are discussed.

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