Integrated dehumidification and downdraft evaporative cooling system for a hot-humid climate

Unlike in hot-dry climates, in hot-humid climates evaporative cooling techniques are not readily suitable for space cooling. In order to effectively use evaporative cooling in hot-humid climates, dehumidification of ambient air is necessary before it passes over an evaporative medium for cooling. The present study explores the combined process of dehumidification and evaporation and its effect on thermal comfort in a typical small residential building located in a hot humid climate. A novel system has been investigated with the combination of an Earth Tube Ventilation (ETV) (for pre-cooling of air), a rotary wheel desiccant dehumidifier (for dehumidification) along with a Passive Downdraught Evaporative Cooling (PDEC) tower (for evaporation) in that order.Parametric simulations using the EnergyPlus tool have been conducted in order to determine the critical dimensions and parameters of the proposed system, such as desiccant system sizing, PDEC tower height, and air and water flow rate at various points of the system. Results of indoor air temperature, humidity levels and volumetric air flow rates in the building spaces were obtained to study the influence of the proposed combined system on human thermal comfort. On a typical hot day the results from the proposed system show a relatively constant indoor air temperature of 28 °C (as opposed to peak indoor temperature of 36 °C occurred by means of natural ventilation) and indoor relative humidity in the range of 62 % - 68 %. The volumetric airflow rate from the outlet of the PDEC tower is in the range of 2.97 - 3.41 m3/s which is well within recommended levels for a dwelling unit. The proposed system displays a significant potential for providing space cooling in hot-humid climates as it paves an alternate way to the conventional energy consuming vapour compression Air Conditioning units

Passive Architectural Design Index applied to vernacular and passive buildings

Vernacular architecture's use of passive building techniques has been developed in response to the prevailing climatic conditions of the past. Today, buildings are designed with complete indifference to the climate and materials. Energy consumption in buildings is mainly connected to space cooling, supply of hot water, lighting, cooking and, use of appliances. Space cooling and lighting are directly influenced by the design of the building. Energy codes should be concerned with "sufficiency" as well as "efficiency". A more economic and ecological approach to building design is needed

Investigating optimum cooling set point temperature and air velocity for thermal comfort and energy conservation in mixed-mode buildings in India

In warm and hot climates, ceiling fans and/or air conditioners (ACs) are used to maintain thermal comfort. Ceiling fans provide air movement near the skin, which enhances the evaporation of sweat, reduces heat stress, and enhances thermal comfort. This is also called the cooling effect. However, AC usage behaviour and the effects of elevated air speed through the use of ceiling fans on indoor operative temperature during AC usage are not widely studied. This study investigated the optimum AC (cooling) set point temperature and air velocity necessary for maintaining thermal comfort while achieving energy conservation, in mixed-mode buildings in India, through field studies by using used custom-built Internet of Things (IOT) devices. In the current study, the results indicate a 79% probability that comfort conditions can be maintained by achieving a temperature drop of 3K. If this drop can be achieved, as much as possible, through passive measures, the duration of AC operation and its energy consumption are reduced, at least by 67.5 and 58.4%, respectively. During the air-conditioned period, there is a possibility that the cooing effect is reduced because of increase in operative temperature due to ceiling fan operation. Therefore, the optimum solution is to maintain the highest AC set point and minimum fan speed setting that are acceptable

Harnessing energy performance certificates for deep energy renovation : policy recommendations and evidence from testing

To achieve the EU's energy efficiency targets, both the rate of building energy renovation and its depth, i.e., the amount of energy savings post renovation need to be improved. Energy Performance Certificates (EPCs) are key to make energy efficiency measures transparent for the building market and to promote the energy efficiency of buildings through renovation. The revision of the Energy Performance of Buildings Directive (EPBD) is seen as a pre-condition to meet the Renovation Wave objectives and to reach a highly energy efficient and decarbonized building stock by 2050. One focus of the current revision of the EPBD is therefore the improvement of EPCs. QualDeEPC - High-quality Energy Performance Assessment and Certification in Europe Accelerating Deep Energy Renovation, funded under the EU's Horizon 2020 programme, is a project that aims to improve EPCs. Following an EU-wide review of existing EPC schemes, and extensive stakeholder discussions in the seven partner countries, QualDeEPC found that EPCs and EPC schemes need to enhance particularly in the following three ways: 1. Establish a close link between EPCs and deep energy renovation 2. Improve the quality of EPC schemes, i.e., both the EPCs and their data, and the processes of assessment, certification, verification 3. Improve cross-EU convergence of EPC schemes

Next-generation energy performance certificates and deep energy renovation

An important instrument to enhance the market uptake of energy-efficient new buildings and the energy-efficient renovation of existing buildings in the European Union (EU) are the Energy Performance Certificates (EPC). However, their implementation and use has varied between EU Member States. The European Commission has therefore provided funding to a number of Horizon2020 projects to develop next-generation EPC schemes. One of these is the QualDeEPC project, aiming to both improve quality and cross-EU convergence of EPC schemes, and particularly the link between EPCs and deep renovation. The objective of the project is to improve the practical implementation of the assessment, issuance, design, and use of EPCs as well as their renovation recommendations, in the participating countries and beyond. This paper presents the policy proposals and concepts for tools that the QualDeEPC project has developed as priorities for enhanced EPC schemes: - Improving the recommendations for renovation, which are provided on the EPCs, towards deep energy renovation - An online tool for comparing EPC recommendations to deep energy renovation recommendations - Creating Deep Renovation Network Platforms (One-stop Shops plus networking and joint communication of supply-side actors) - Regular mandatory EPC assessor training (on assessment and renovation recommendations) required for certification/accreditation and registry - Achieving a high user-friendliness of the EPC - Voluntary/mandatory advertising guidelines for EPCs - Improving compliance with the mandatory use of EPCs in real estate advertisements The paper will focus on the aspects related to improving the impact of EPCs for stimulating deep renovation. It will also present lessons learnt from the discussion with stakeholders at national and European workshops and from the testing of the proposals and tools in around 100 buildings, as well as from the first steps of their country-specific adaptation

Energy performance, potential and optimisation of mixed-mode buildings in India

Most air-conditioned buildings in India operate as Mixed-Mode Buildings (MMBs), either fully air-conditioned or with natural ventilation depending on the weather. Energy consumption for space cooling is a vital end-use service in buildings. Air-conditioning is expected to increase significantly due to high growth estimates in building construction, sales of Room Air-Conditioners (RACs), and real income growth. Therefore, this thesis examines the most influential design and control parameters that influence the potential of MMBs in India in relation to their thermal and energy performance. The primary features of MMBs analysed in the research project are as follows: shutting windows at night makes night ventilation redundant; natural ventilation through ceiling fans and windows is utilised to maintain optimal thermal conditions in naturally-ventilated mode and RACs are employed in air-conditioned mode. This thesis poses three research questions and aims to answer them. Firstly, what are the research gaps in assessing thermal and energy performance in mixed-mode buildings in India? Secondly, what is their potential concerning key operating conditions, and which parameters affect this potential? Lastly, how can these influential parameters be optimised? To answer these questions, three research methods were employed: 1) literature review; 2) large-scale simulation of building energy performance combined with uncertainty and sensitivity analysis; and 3) field studies of user behaviour with regards to RACs and the impact of ceiling fans and RACs on indoor conditions and energy consumption. The study identifies the cooling set point temperature as the most influential control parameter. In general, input parameters related to building design, shape and geometry were considered more important than those related to construction parameters. Furthermore, the study highlights that a set point temperature of 28 or 30°C is sufficient to maintain indoor comfort according to the Indian Model for Adaptive Comfort (IMAC) for residential buildings. If a specific airflow is required, it would use the least energy to run the ceiling fan at a low speed, usually set at 1

Relevant technologies for the energy transition in Germany, with potential relevance for Japan : a preparatory study in the framework of the GJETC project

In this project, an overview and prioritization of relevant technologies of the German energy transition are presented in a consolidated form. Many of the relevant technologies have already been developed and deployed to the market. However, in various sectors like system integration or sector coupling, innovation needs remain, as well as in-depth research on further possibilities and potentials for cost degression and technology optimization for all technologies

D2.1 report on local EPC situation and cross-country comparison matrix : QualDeEPC H2020 project

Considering that 40% of the European Union's energy consumption can be traced back to its buildings, it is essential to improve their energy efficiency in order to achieve the EU's energy efficiency targets. Both the rate of energy renovation and its depth, i.e. the amount of energy savings during a renovation, need to be improved. Energy Performance Certificates (EPC), regulated by the EU's Energy Performance of Buildings Directive (EPBD), are an important instrument to enhance the market uptake of energy-efficient new buildings and the energy-efficient renovation of existing buildings. Against this background, the Horizon2020 funded project QualDeEPC will work on EU-wide convergence of the building assessment and the issuance, design, and use of quality-enhanced EPCs as well as their recommendations for building renovation. The aim is to make these recommendations coherent with deep energy renovation towards a nearly-zero energy building stock by 2050. The first part of the QualDeEPC project (work package 2) aims to identify the priorities for elements of EPC schemes that show a need to be improved, and for which the project will investigate further and propose how the elements can be improved. The first step in identifying these priorities is taking stock of the existing EPC schemes. Based on the input from all national consortium partners and other sources, the Wuppertal Institute prepared this detailed overview of the country-specific EPC assessment and certification procedures and their links to other policies and programmes, existing initiatives, and projects. The analysis was based on a list of almost 50 potential options for enhancing the existing EPC schemes. The aim of this deliverable is to present this stock-taking by a detailed analysis on which of the potential enhanced EPC elements are already implemented in which form in which country, covering all 28 countries that were EU member states until 31 January 2020. All partners conducted bilateral interviews with the major actors in the EPC procedures, including executive bodies on EPC at regional and/or national level. For countries not represented in the Consortium, Wuppertal Institut and EAP conducted specific literature research, e.g. from the Concerted Action EPBD, and aimed to obtain contributions from other member states. The information collected allows a detailed presentation on the elements implemented as well as a cross-country comparison matrix (see Annex I) in this report, which outlines the current EPC practices across the EU regarding the elements of a good practice scheme or innovative improvement options, their comparability, compliance with EU legislation, and to which extent they differ or converge. The results show, once more, the high diversity in EPC schemes across the EU. They also provide useful information in at least two directions: 1) which improvement options are not yet implemented at all or in sufficient quality in most QualDeEPC partner countries as well as other EU member states, and could therefore be interesting candidates for the further work of the QualDeEPC project in development, testing, discussion, and possibly implementation of elements for enhanced and converging EPC schemes; and 2) which countries, within or beyond the QualDeEPC project, offer good practice examples for the implementation of these options that could serve to guide the development and implementation in other countries. This deliverable will thus serve as a basis for the upcoming tasks to develop priorities and actual proposals for improvement of EPC schemes

Energy performance of room air-conditioners and ceiling fans in mixed-mode buildings

Studies show that people can tolerate elevated temperatures in the presence of appreciable air movement (e.g., from using ceiling fans). This minimises the use of air-conditioners and extends their set-point temperature (Tset), resulting in energy savings in space cooling. However, there is little empirical evidence on the energy savings from using ceiling fans with Room Air-Conditioners (RACs). To address this gap, we analysed the energy performance of RACs with both fixed-speed compressors and inverter technology at different set-point temperatures and ceiling fan speed settings in 15 residential Mixed-Mode Buildings (MMBs) in India. Thermal comfort conditions (as predicted by the Indian Model for Adaptive Comfort-Residential (IMAC-R)) with minimum energy consumption were maintained at a set-point temperature (set) of 28 and 30 C and a fan speed setting of one. Compared with a Tset of 24 °C, a set of 28 and 30 °C resulted in energy savings of 44 and 67%, respectively. With the use of RACs, a configuration with a minimum fan speed was satisfactory for an optimal use of energy and for maintaining the conditions of thermal comfort. In addition, RACs with inverter technology used 34-68% less energy than fixed-speed compressors. With the rising use of RACs, particularly in tropical regions, the study's outcomes offer a significant potential for reducing space-cooling energy consumption and the resultant greenhouse gas (GHG) emissions