Search results for "Natural ventilation"
showing 10 items of 21 documents
Vernacular and bioclimatic architecture and indoor thermal comfort implications in hot-humid climates: An overview
2018
Abstract Sustainable urban development, especially in disadvantaged regions, has increasingly gained a major strategic priority. New settlements and urban regeneration programs have to achieve an improvement of social life quality, promote economic growth and increase environmental protection practices and proper use of local resources. In this framework, building environment development must exploit natural resources with responsible approach by using local materials and traditional techniques. In this end, indoor comfort and energy consumption have to match the territories needs. Low energy and passive heating/cooling techniques should be considered as a valid option in many building proj…
Potential of Natural Ventilation and Vegetation for Achieving Low-Energy Tall Buildings in Tropical Climate: An Overview
2019
Climate change and rise in urban temperatures have further increased the cooling load demands for tall buildings located in hot climatic regions. Cooling loads in tall buildings can be reduced by integrating them with natural ventilation (NV) and building integrated vegetation (BIV) techniques. This study explores the potential of NV and BIV for obtaining low-energy buildings by analyzing ten tall buildings as case studies. Buildings are analyzed for NV, BIV, architecture design parameters, and energy savings. The results show that mixed-mode ventilation is the most commonly employed, and circular building plans have the highest potential for energy savings. Furthermore, the combination of …
Are urban water bodies really cooling?
2020
Abstract Small urban water bodies, like ponds or canals, are often assumed to cool their surroundings during hot periods, when water bodies remain cooler than air during daytime. However, during the night they may be warmer. Sufficient fetch is required for thermal effects to reach a height of 1–2 m, relevant for humans. In the ‘Really cooling water bodies in cities’ (REALCOOL) project thermal effects of typical Dutch urban water bodies were explored, using ENVI-met 4.1.3. This model version enables users to specify intensity of turbulent mixing and light absorption of the water, offering improved water temperature simulations. Local thermal effects near individual water bodies were assesse…
Optimisation of Heat Loss through Ventilation for Residential Buildings
2018
This study presents the results of research on heat loss from various types of residential buildings through ventilation systems. Experimental research was done to analyse the effectiveness of ventilation systems of different types and determine the parameters of air discharged via the ventilation ducts. A model of heat loss from the discharge of exhaust air outside through air ducts has since been developed. Experiments were conducted on three experimental systems of building ventilation: gravitational, mechanical, and supply-exhaust ventilation systems with heat recovery. The proposed model dependencies were used to chart the daily fluctuations of the optimum multiplicity of air exchange …
Role of Sky-gardens in Improving Energy Performance of Tall Buildings
2018
Natural ventilation has been used as a passive strategy for many decades but only now its importance in tall buildings for addressing the issues of high energy usage and reducing carbon footprints is emerging. Sky-gardens can play an important role in successful implementation of natural ventilation through amplification of natural wind speeds. This study presents a state-of-the-art review on optimization of tall buildings energy performance through incorporation of sky-gardens. Pros and cons of use of natural ventilation for multi-story buildings are highlighted. Details of involved technical difficulties and barriers in the construction and operation process of sky-gardens are also given.…
PCM thermal storage design in buildings: Experimental studies and applications to solaria in cold climates
2017
Abstract As energy availability and demand often do not match, thermal energy storage plays a crucial role to take advantage of solar radiation in buildings: in particular, latent heat storage via phase-change material is particularly attractive due to its ability to provide high energy storage density. This paper analyzes the performance of a building-integrated thermal storage system to increase the energy performances of solaria in a cold climate. A wall opposing a highly glazed facade (south oriented) is used as thermal storage with phase change materials embedded in the wall. The study is based on both experimental and simulation studies. The concept considered is particularly suited t…
Redesign of a Rural Building in a Heritage Site in Italy: Towards the Net Zero Energy Target
2017
In order to achieve the ambitious objective of decarbonising the economy, it is mandatory, especially in Europe and in Italy, to include the retrofitting of existing buildings. In a country where a large share of existing buildings have heritage value, it is important to design effective retrofit solutions also in historical buildings. In this context, the paper describes the experience of re-design of an existing rural building located in Sicily, inside the ancient Greeks' “Valley of the Temples”. An energy audit was performed on the building, and its energy uses were thoroughly investigated. A building model was developed in the TRNSYS environment and its performances validated. The valid…
Phase Change Materials Applications to Optimize Cooling Performance of Buildings in the Mediterranean Area: A Parametric Analysis
2015
Abstract Building integrated thermal energy storage systems cover a wide range of techniques and solutions depending on technology applications and aims. They however all have in common the concept behind: being able to store energy for later use in order to reduce the time mismatch between energy availability and demand. In this context, Phase Change Materials (PCMs) fit the above description, since they would allow for mostly isothermal phase change within normal thermal comfort range. In order to face the typical challenges of the Mediterranean climate, the following concept was elaborated: the idea is to use the phase change mechanics as a substitute to the thermal inertia of massive wa…
Ventilation Rates and Unsatisfied Percentage from Indoor CO2 Concentration
2010
This work reports the results of a survey carried out on a hall in a historic building in Palermo (Italy) with the aim of assessing the air quality by means of objective measurement of carbon dioxide (CO2) concentration and its subjective evaluation through a questionnaire. The measured values of CO2 concentration were compared with those evaluated using the Meckler equation under steady-state conditions, having verified necessary parameters such as the constancy of the indoor and outdoor CO2 levels and the uniformity of the CO 2 generation rate for all the occupants. The positive correspondence between measured and calculated results allowed us to utilise, under differing circumstances, t…
An Experimental Investigation on the Air Permeability of Passive Ventilation Grilles
2015
Abstract The need of increasing both energy saving and acoustic insulation has leaded to the design of lowest air permeability frames resulting in the worsening of indoor air quality. Moreover, sometime in several civil-use existing buildings (i.e. schools or houses, historical buildings) mechanical ventilation systems cannot be installed due to non-removable constraints. In these cases, passive ventilation grilles are a cheap and effective solution for the ventilation. This work deals with an in-depth experimental analysis about the air permeability values measured over a set of passive ventilation grilles available on the market. Obtained results often showed performances very far to thos…