Ventilative Cooling in Shopping Centers' Retrofit: The Mercado Del Val Case Study ☆

Abstract Nearly all retail locations use ventilation and cooling systems to ensure adequate air exchange for health reasons and indoor comfort temperatures. These systems can run for over 2,000 hours per year and we expect that average operating hours will continue to rise across Europe because of the continued trend towards longer opening hours and increased number of opening days. Shopping malls often enclose large open spaces and atria with high solar and internal gains that can drive ventilative cooling. This paper presents the ventilative cooling strategy proposed, analysed and implemented in one of the three demo cases of the project: Mercado del Val, the historic market of the city of Valladolid. Once we determined the climate suitability, we defined a ventilative cooling strategy that exploits openings in the facade and in the skylight to promote stack effect ventilation. Considering that indoor spaces of a shopping centre highly interacts among each other, a multizone based analysis of airflows is needed to evaluate the ventilative cooling strategy effectiveness and to assess potential energy savings. We sized openings area and location on the facade, taking into account design constraints, and we assessed their performances in terms of energy, thermal comfort and indoor air quality. Results show the potential cooling load reduction, with the achievement of acceptable thermal comfort due to the ventilative cooling in the shopping mall. The analysis performed supported the design decision process towards cost effective low energy shopping centre

Design strategies for non-residential zero-energy buildings: lessons learned from Task40/Annex 52: towards net zero-energy solar buildings

Net zero-energy buildings (Net ZEBs) have been the object of various studies in recent years as various countries have set this performance as long-term goal of their energy policies. Designing successful Net ZEBs represents a challenge since the definitions are yet generic, the assessment method and monitoring approach are under development and the literature is relatively scarce about the best sets of solutions for different typologies and climates likely to deliver an actual and reliable performance in terms of energy balance (used consumed vs. generated) on a costeffective basis. The International collaborative research initiative between the Solar Heating and Cooling (SHC) and the Energy Conservation in Buildings and Community Systems (ECBCS) through Task 40/Annex 52 - Towards Net-Zero Energy Solar Buildings-, summarises most of the recent developments in this field. The authors of this article, who are participants in this task, are providing insights from on-going research work on some best practice leading projects which have been the object of an exploratory cross-case analysis in order to facilitate identification of the set of relevant design strategies. The close inspection of the strategies and indicators of the relative performance of the projects revealed interesting features about the combination of design challenges with techniques and technologies responsible for delivering the Zero Energy performance

Optimised Parametric Model of a Modular Multifunctional Climate Adaptive Facade for Shopping Centers Retrofitting

A modular multifunctional façade for the retrofit of shopping malls, capable of adapting to different climates and to the existing building features both by the presence of movable components and by proper sizing of the fixed ones, is under development within the European FP7 project CommONEnergy. In particular, this curtain-wall façade is equipped with a fixed shading system, a photovoltaic panel with a battery feeding the automated openings for natural ventilation. The aim of this work is to define a reliable parametric model for a multi-functional façade system, to support designers with a set of useful data for the holistic design of the façade configuration depending on climate, orientation and building use. Firstly, a reference zone model for the façade was devised; this had to be both representative of reality and smartly defined for simulation software implementation. Besides the definition of the façade model parameters, all unknown design parameters were identified with their minimum and maximum values, depending on different possible applications and environmental conditions in which the façade could be applied. The inputs for the model were defined in a parametric matrix and included: facade module size, façade orientation, climate, window typology (thermal transmittance and g-value), distance between the shading lamellas, tilt angle, and openable window size. The simulation engine was decoupled: visual comfort and artificial lighting use were assessed with Radiance, while the façade thermal behaviour was evaluated by means of building energy simulations in TRNSYS, taking into consideration the daylight assessment results. For each simulated configuration, a set of relevant outputs fields for Indoor Air Quality, thermal and visual comfort, and energy performance were derived. The main considered performance indicators were the long-term percentage of people dissatisfied, the number of hours when CO2 concentration was within the recommended values for each of the categories defined by EN 15251:2007, the illuminance provided by daylight, the energy consumption due to lighting, ventilation, heating and cooling, and the energy generated by the PV panel. Moreover, all outputs were collected in a pre-design support tool comprised of a database accessible through a filtering system to gather the desired performances. This work highlights the role of thermal and daylighting simulation in the design of an adaptive multifunctional façade through the definition of a methodology for the support at the pre-design phase

Ventilative Cooling potential tool User guide - Version 1.0

The new initiatives and regulation towards low energy buildings forces designers to exploit the cooling potential of the climate to reduce the overheating occurrence and to improve thermal comfort indoors. Climate analysis is particularly useful at early design stages to support decision making towards cost-effective ventilative cooling solutions. The first step to design ventilative cooling is to analyse the climate potential, in other words the natural forces that drives natural ventilation (outdoor temperature, humidity and wind velocities and direction). As buildings with different use patterns, envelope characteristics and internal loads level react differently to the external climate condition, the climate analysis cannot abstract from building characteristics and use. The ventilative cooling potential tool (VC tool) was developed within International Energy Agency (IEA) Annex 62 project with the aim to assess the potential effectiveness of ventilative cooling strategies by taking into account also building envelope thermal properties, occupancy patterns, internal gains and ventilation needs

A framework for the technical evaluation of residential buildings’ energy retrofit

Despite a wide range of energy-efficient technologies, financial products and public incentives are already available, the private as well as the public sector are struggling to invest in energy efficient solutions for buildings. The primary barriers are the high initial cost and the uncertain payback period of the energy refurbishment. Allowing for different scenario testing and considering interactions among different building energy systems, building energy simulation tools can help investors overcoming such barriers by offering support to the technical planning of energy refurbishment kits through quantitative information rather than qualitative. The energy performance and comfort of three reference multifamily residential buildings typologies were evaluated considering three envelope retrofitting performance levels (high-medium-low insulated and airtight) and different heating and domestic hot water systems (heat pump, boiler, district heating). The tested envelope retrofitting performance levels allow for heating need reduction between 50% and 90% compared to the reference case. The active cooling system is not accounted for and building energy simulations outputs include thermal comfort evaluation and overheating risk assessment during the summer season. The potential of photovoltaic system combined with heat pump is evaluated in the three reference cases leading to up to 30% of load coverage

Low Polluting Building Materials and Ventilation for Good Air Quality in Residential Buildings: A Cost–Benefit Study

Nowadays, people spend an average of 87% of their time inside buildings, and about 69% at home. Hence, it is essential to ensure the highest possible level of indoor air quality (IAQ). Providing that the quality of the outdoor air is acceptable, the IAQ level is improved by increasing the ventilation rates. However, this means that a larger volume of air must be cooled down or warmed up to ensure the same level of thermal comfort. The aim of this study was to conduct a cost–benefit analysis of the IAQ in residential buildings. A case-study building was defined, and three sets of materials with different pollution emission levels were chosen: High, low, and very low. For each option, the ventilation rates required to have the same IAQ level were calculated, and the consequent energy consumption and costs were estimated by means of dynamic thermal simulation. The results show the range of the initial capital cost that could be compensated for by lower running costs, and the effect of each energy and economic input assumption on the appraisal of the affordable capital cost. In the discussion, insights into the IAQ co-benefits are also given

Plus Energy Building: operational definition and assessment

Considering the amount of existing buildings, decarbonizing the building stock requires new buildings designed to reach the highest performance. The nearly-Zero Energy Buildings (nZEB) standard needs to be overtaken by Plus Energy Buildings (PEB) that presents the potential to produce more energy than the consumption over a specific period. Several studies investigated the potential of a building to achieve a plus energy balance, however, there is still a lack of a comprehensive and shared framework for designing and assessing the performance of a PEB. To cope with this issue, the authors identified a series of key aspects that needs to be stated in a consistent framework for PEB, and in particular: i) the balance contributions, ii) the physical boundaries, iii) the time span for the balance assessment, iv) the metrics for evaluating PEBs, v) the approach for evaluating load matching and grid interaction, vi) Indoor Environmental Quality and user satisfaction as added values of a PEB. The authors performed a comprehensive review identifying 82 papers dealing with PEB and deducing how the key aspects have been addressed. The literature overview provides the background for proposing an approach for the PEB definition and to introduce an operational assessment focused on providing the main statements focusing on PEB performance evaluation both during the design and operative phase.(c) 2022 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)

Systemic solution-sets

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