scholarly journals LOW-COST AND NON-INVASIVE ENERGY RECOVERY TECHNIQUES FOR PUBLIC RESIDENTIAL BUILDINGS MADE WITH GREAT PANEL STRUCTURES IN ITALY

2019 ◽  
Vol 14 (3) ◽  
pp. 23-46
Author(s):  
Frida Bazzocchi ◽  
Sara Ticci ◽  
Vincenzo Di Naso ◽  
Andrea Rocchetti

In Italy, a large stock of public housing was built during the 1970s and 1980s with industrialized/prefabricated techniques. These buildings have envelopes characterized by the presence of many thermal bridges and low transmittance values. In addition, they feature inefficient single heating systems in residential units and no cooling/ventilation systems. As a result, these buildings require urgent energy retrofitting actions, and it is therefore necessary to define procedures that will guarantee effective results. The possible interventions must be compatible with building construction techniques as well as be minimally invasive and inexpensive. There are only a limited number of technical solutions, considering that residents should not have to move out during the renovations. In most Italian climatic zones, current interventions are usually linked to external insulation and window replacement, leading to an improvement in energy performance and comfort only during winter. Internal comfort conditions tend to worsen in summer months because seasonal temperatures tend to increase by a few degrees. Therefore, solutions should be proposed that will improve both summer and winter conditions. This work proposes an energy recovery procedure applied to a representative building from the abovementioned period located in the Florence area and constructed with an industrialized system named the “tunnel system” (great panels structure). The procedure used in this study provides for the redevelopment of the envelope and the application of a simple mechanical ventilation system to achieve substantial energy savings and improved indoor comfort conditions.

2020 ◽  
Vol 13 (1) ◽  
pp. 235
Author(s):  
Fernando Martín-Consuegra ◽  
Fernando de Frutos ◽  
Ignacio Oteiza ◽  
Carmen Alonso ◽  
Borja Frutos

This study quantified the improvement in energy efficiency following passive renovation of the thermal envelope in highly inefficient residential complexes on the outskirts of the city of Madrid. A case study was conducted of a single-family terrace housing, representative of the smallest size subsidized dwellings built in Spain for workers in the nineteen fifties and sixties. Two units of similar characteristics, one in its original state and the other renovated, were analyzed in detail against their urban setting with an experimental method proposed hereunder for simplified, minimal monitoring. The dwellings were compared on the grounds of indoor environment quality parameters recorded over a period covering both winter and summer months. That information was supplemented with an analysis of the energy consumption metered. The result was a low-cost, reasonably accurate measure of the improvements gained in the renovated unit. The monitoring output data were entered in a theoretical energy efficiency model for the entire neighborhood to obtain an estimate of the potential for energy savings if the entire urban complex were renovated.


Author(s):  
Heangwoo Lee ◽  
Xiaolong Zhao ◽  
Janghoo Seo

Recent studies on light shelves found that building energy efficiency could be maximized by applying photovoltaic (PV) modules to light shelf reflectors. Although PV modules generate a substantial amount of heat and change the consumption of indoor heating and cooling energy, performance evaluations carried out thus far have not considered these factors. This study validated the effectiveness of PV module light shelves and determined optimal specifications while considering heating and cooling energy savings. A full-scale testbed was built to evaluate performance according to light shelf variables. The uniformity ratio was found to improve according to the light shelf angle value and decreased as the PV module installation area increased. It was determined that PV modules should be considered in the design of light shelves as their daylighting and concentration efficiency change according to their angles. PV modules installed on light shelves were also found to change the indoor cooling and heating environment; the degree of such change increased as the area of the PV module increased. Lastly, light shelf specifications for reducing building energy, including heating and cooling energy, were not found to apply to PV modules since PV modules on light shelf reflectors increase building energy consumption.


Author(s):  
Jerzy Sowa ◽  
Maciej Mijakowski

A humidity-sensitive demand-controlled ventilation system is known for many years. It has been developed and commonly applied in regions with an oceanic climate. Some attempts were made to introduce this solution in Poland in a much severe continental climate. The article evaluates this system's performance and energy consumption applied in an 8-floor multi-unit residential building, virtual reference building described by the National Energy Conservation Agency NAPE, Poland. The simulations using the computer program CONTAM were performed for the whole hating season for Warsaw's climate. Besides passive stack ventilation that worked as a reference, two versions of humidity-sensitive demand-controlled ventilation were checked. The difference between them lies in applying the additional roof fans that convert the system to hybrid. The study confirmed that the application of demand-controlled ventilation in multi-unit residential buildings in a continental climate with warm summer (Dfb) leads to significant energy savings. However, the efforts to ensure acceptable indoor air quality require hybrid ventilation, which reduces the energy benefits. It is especially visible when primary energy use is analyzed.


2020 ◽  
Vol 10 (12) ◽  
pp. 4336
Author(s):  
Yue Hu ◽  
Per Kvols Heiselberg ◽  
Tine Steen Larsen

A ventilated window system enhanced by phase change material (PCM) has been developed, and its energy-saving potential examined in previous works. In this paper, the ventilation control strategies are further developed, to improve the energy-saving potential of the PCM energy storage. The influence of ventilation airflow rate on the energy-saving potential of the PCM storage is firstly studied based on an EnergyPlus model of a sustainable low energy house located in New York. It shows that in summer, the optimized ventilation airflow rate is 300 m3/h. The energy-saving of utilizing a ventilated window with PCM energy storage is 10.1% compared to using a stand-alone ventilated window, and 12.0% compared to using a standard window. In winter, the optimized ventilation airflow rate is 102 m3/h. The energy-saving of utilizing a ventilated window with PCM energy storage is 26.6% compared to using a stand-alone ventilated window, and 32.8% compared to using a standard window. Based on the optimized ventilation airflow rate, a demand control ventilation strategy, which personalizes the air supply and heat pump setting based on the demand of each room, is proposed and its energy-saving potential examined. The results show that the energy savings of using demand control compared to a constant ventilation airflow rate in the house is 14.7% in summer and 30.4% in winter.


2018 ◽  
Vol 49 ◽  
pp. 00068 ◽  
Author(s):  
Piotr Lis

In the face of a constant increase in demand for energy, one of the important sources will be its saving and efficient use. The search for the greatest opportunities in this area should focus on the areas where the highest energy consumption occurs. The dominant role here is played by the communal and living sector, to the extent that it is the sub-sector of buildings with a majority share of residential buildings. The article presents the expected energy effects of measures reducing energy consumption for heating residential buildings in the whole country. The author used statistical data of the Central Statistical Office available in the database of this institution. These data were identified and searched for as suitable for the purposes of this article and were used as a basis for calculations and analyses. The calculations show that only thanks to simple actions such as improvement of thermal insulation of envelope components it is possible to reduce energy consumption for heating of residential buildings by over 70% in relation to the situation in 2011. The potential energy effect will also translate into an economic and environmental effect. Qualitative measures such as improving the performance of the heating and ventilation system of a building and/or changing the energy carrier will also reduce energy consumption for this purpose, but they are not the subject of this study.


Energies ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 6068
Author(s):  
Remy Carlier ◽  
Mohammad Dabbagh ◽  
Moncef Krarti

This paper evaluates the potential energy savings when switchable insulation systems (SIS) are applied to walls of residential buildings located in Belgium and other locations in Europe. The study considers two low-energy prototypical dwellings (an apartment and a detached house) that are representative of post-2010 constructions and renovations in Belgium. Using an 3R2C-based analysis tool, the performance of both dwellings is evaluated with static and dynamic wall insulation systems. First, the switchable insulating system is described along with its associated simple 2-step rule-based control strategy. Then the modeling strategy and simulation analysis tools are presented. In Belgium, it was found that SIS-integrated walls allow energy savings up to 3.7% for space heating and up to 98% for cooling. Moreover, it was found that to further reduce the energy consumption of SIS-integrated buildings in various European climates, thermal mass placement needs to be considered. By optimizing the placement and the parameters of the various wall layers, it is possible to increase the space heating savings by up to a factor of 4 and those of cooling by up to a factor of 2.5.


2014 ◽  
Vol 60 (3) ◽  
pp. 335-347
Author(s):  
A. Życzyńska ◽  
T. Cholewa

Abstract The energy saving tendencies, in reference to residential buildings, can be recently seen in Europe and in the world. Therefore, there are a lot of studies being conducted aiming to find technical solutions in order to improve the energy efficiency of existing, modernized, and also new buildings. However, there are obligatory solutions and requirements, which must be implemented during designing stage of the building envelope and its heating/cooling system. They are gathered in the national regulations. The paper describes the process of raising the energy standard of buildings between 1974–2021 in Poland. Therefore, the objective of this study is to show energy savings, which can be generated by modernization of thermal insulation of partitions of existing buildings and by the use of different ways of heat supply. The calculations are made on the selected multi-family buildings located in Poland, with the assumption of a 15 years payback time. It is shown that it is not possible to cover the costs of the modernization works by the projected savings with the compliance to the assumption of 15 years payback time.


Author(s):  
О. Симбирев ◽  
O. Simbirev

The main problem highlighted in the article is the deviation of the microclimate parameters from the standard values due to the improper organization of airflow in the residential rooms of apartment buildings. The objective is to obtain a working mathematical model of the natural ventilation system, its study for optimization or modernization. The analysis of the normative literature, scientific works of domestic and foreign scientists, developments in the field of natural ventilation and ventilation of residential buildings is carried out. A mathematical model of air exchange of a residential room with convection is presented and analyzed. The flow rate and air temperature, the temperature on the surface of the heater are set as boundary conditions when creating a mathematical model. The features and regularities of airflow distribution in the room obtained as a result of mathematical modeling are revealed. The distributions of air velocity in the room are given. Difficulties of the organization of effective natural inflow of air and the problems with design of valves of infiltration are designated. Technical solutions aimed at improving the quality of indoor microclimate and energy saving are proposed.


Author(s):  
Elvire Katramiz ◽  
Nesreen Ghaddar ◽  
Kamel Ghali

Abstract The mixed-mode ventilation (MMV) system is an energy-friendly ventilation technique that combines natural ventilation (NV) with mechanical air conditioning (AC). It draws in fresh air when the outdoor conditions are favorable or activates otherwise the AC system during occupancy hours. To improve performance of the MMV system, it is proposed to integrate it with an intermittent personalized ventilation (IPV) system. IPV delivers cool clean air intermittently to the occupant and enhances occupant thermal comfort. With the proper ventilation control strategy, IPV can aid MMV by increasing NV mode operational hours, and improve the energy performance of the AC system by relaxing the required macroclimate set point temperature. The aim of this work is to study the IPV+MMV system performance for an office space application in terms of thermal comfort and energy savings through the implementation of an appropriate control strategy. A validated computational fluid dynamics (CFD) model of an office space equipped with IPV is used to assess the thermal fields in the vicinity of an occupant. It is then coupled with a transient bio-heat and comfort models to find the overall thermal comfort levels. Subsequently, a building-performance simulation study is performed using Integrated Environmental Solutions-Virtual Environment (IES-VE) for an office in Beirut, Lebanon for the typical summer month of July. An energy analysis is conducted to predict the savings of the suggested design in comparison to the conventional AC system. Results showed that the use of IPV units and MMV significantly reduced the number of AC operation hours while providing thermal comfort.


Author(s):  
Hua Chen ◽  
Qianqian Di

To improve the applicability of water-cooled air-conditioners in the domestic sector, the development of a prediction model for energy performance analysis is needed. This paper addressed the development of an empirical model for predicting the operation performance and the annual energy consumption for the use of water-cooled air-conditioners. An experimental prototype was set up and tested in an environmental chamber in validating the empirical model. The predictions compared well with the experimental results. Furthermore, a high-rise residential building whole-year energy consumption simulation on applications of water-cooled air conditioners in South china was also analyzed. The results show 20.4% energy savings over air-cooled units while the increase in water-side consumption is 31.1%. The overall energy savings were estimated at 16.2% when including the additional water costs.


Sign in / Sign up

Export Citation Format

Share Document