• Energy Research
• 11. Sustainability close
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Abstract A sustainable building design should be compliant with the even more pressing energy saving requirements – as in NZEB – and high levels of Indoor Environmental Quality. Despite it is accepted that different facets of IEQ could have antagonistic effects on building energy demand, relatively few studies are aimed at investigating the mutual interaction among its four components. From this point of view, the hue-heat hypothesis is based on the idea that light and colors can affect the thermal perception. Particularly, spectral power distributions of light shifted to short wavelengths seem to promote a cooler thermal perception and vice-versa. To verify this still debated hypothesis, this paper is focused on a subjective investigation carried out in a special mechanically conditioned test room provided with white-tuning LED sources. 163 volunteers have been exposed to two different lighting scenarios characterized by warm (3000 K) and cool lights (6000 K) at a fixed work-plane illuminance value (300 lx) at two different operative temperature values (20 °C and 25 °C). Obtained results seem to confirm that warm light results in a warmer thermal sensation. Probably due to thermohygrometric conditions relatively close to comfort, no effects on thermal evaluation, and thermal preference were found under both microclimatic scenarios. This was also about the effects of CCT on humidity perception and game performances.

Solar energy has been widely introduced in the building market to provide electricity, heating and domes-tic hot water for a sustainable development. However, the low-density and the mismatch between energysupply and demand make appropriate its combination with thermal energy storage (TES) systems. Theintegration of these technologies (solar thermal and TES) in the building design is a key aspect to reduceenergy consumption. Latent heat storage using phase change materials (PCM) presents an advantage incomparison to conventional sensible heat storage systems due to the required volume. In this context,an innovative system that integrates PCM inside the structural horizontal building component is pre-sented in this paper. The slab consisted of a prefabricated concrete element with 14 channels filled withmacro-encapsulated PCM which is used as a storage unit and a heating supply. In order to melt the PCMthe system is coupled to a solar air collector. The prototype is tested in an experimental facility locatedin Puigverd de Lleida (Spain) where its thermal performance is evaluated under real weather conditions.This study demonstrates the high potential of the concrete slab on reducing the energy consumptioncompared to a conventional heating system. The work partially funded by the Spanish government (ENE2015-64117-C5-1-R (MINECO/FEDER), ENE2015-64117-C5-3-R (MINECO/FEDER), and ULLE10-4E-1305). The authors wouldlike to thank the Catalan Government for the quality accreditation given to their research group (2014 SGR 123) and thecity hall of Puigverd de Lleida. This project has received fundingfrom the Eurpean Commission Seventh Framework Programme(FP/2007-2013) under Grant agreement Nº PIRSES-GA-2013-610692 (INNOSTORAGE) and from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 657466 (INPATH-TES). Alvaro de Gracia would like to thank Ministerio de Economia y Competitividad de España for Grant Juan dela Cierva, FJCI-2014-19940.

Abstract The “individual” accounting of thermal energy in household applications (heating, cooling, hot water) is a very essential tool for increasing energy efficiency of buildings equipped by central plants. Furthermore, the availability of real time energy consumptions data, typical of smart metering, enables users to identify the causes of any waste of energy and consequently to adopt adequate strategies to improve energy efficiency. Modern devices for thermal energy measurement and accounting are rarely present in historical buildings, despite energy consumptions are not negligible. In fact, historical buildings exhibit architectural constraints and plant configurations that strongly discourage the use of direct heat meters, both on a technical and economic point of view. This paper primarily deals with an in-depth analysis of thermal energy measurement devices for historical building applications. Furthermore, the authors show the results of a specific metrological analysis that enables both a comparison among the different options and the evaluation of the main criticalities about thermal energy measurements in historical buildings. The authors estimated typical uncertainties in heat accounting systems ranging from about 4.4% (direct heat meters) to 21.6% (insertion time counter compensated with degree-days). Intermediate performance for uncertainty has been estimated for heat cost allocators (about 9.2%) and for not compensated insertion time counters (about 13.4%), respectively.

Abstract This paper pays tribute to Povl Ole Fanger, the late professor at the Technical University of Denmark. His scientific studies, focused on the main parameters affecting indoor environmental quality, have inspired (and still inspire) professional design engineers and academic researchers on human thermal comfort and indoor air quality over the last five decades. In addition, he strongly contributed to the creation of a “European School” that addressed engineering issues and was well integrated with the American School, which was characterised (at that time) by a physiological approach. Ten years after his death, this paper is a memorial of his research in the field of thermal comfort and some aspects of indoor air quality. Only the original papers of this Danish scientist will be discussed. The analysis of each single topic of his research and of its impact on past and present research would require more space than would be available in a review article. The authors are confident that the research described in this paper will serve as a beacon for researchers working on thermal comfort now and in the future.

Abstract Buildings are responsible for around 40% of energy consumption and CO2-eq emissions at the European Union (EU) level, thus, it is widely recognized that the pathway towards sustainability should pass through an important renovation of the building stock. This study proposes a novel approach for planning the energy retrofit of neighborhoods of buildings. The main novelties introduced are: 1) considering the stochastic human behavior that deeply affects energy demand, by setting the usage profiles according to normal distributions; 2) considering the effects of global warming on energy retrofit measures (ERMs), by assuming different Representative Concentration Pathways (RCPs) as boundary conditions. The proposed approach is based on the coupling between EnergyPlus, used as dynamic energy simulator, and MATLAB®, used as postprocessing engine. The year 2035 is considered as the reference year of the analysis, because it is a mid-term time horizon. As case study, an existing neighborhood in Naples (Italy) has been investigated, with the aim to determine the ERMs combination that minimizes primary energy consumption (PEC), running cost (RC) and CO2-eq emissions. Three different RCPs have been considered: RCP 4.5 50% warming, RCP 8.5 50% warming and RCP 8.5 95% warming. For each of them, six different scenarios have been investigated – i.e., neighborhood as built and five retrofit combinations. Results show that for all the RCPs the retrofit combination that includes all ERMs – i.e., measures on the envelopes and on the primary energy systems – produces the highest reductions of PEC, RC and CO2-eq emissions.

With the recent trend of moving towards a more sustainable economy, the interest on designing buildings with lower cost and environmental impact has grown significantly. In this context, multi-objective optimization has attracted much attention in building design as a tool to study trade-off solutions (“cost” vs “environmental impact”) resulting from the optimization of conflicting objectives. One major limitation of this approach (as applied to building design) is that it is computationally demanding due to the need to optimize several objectives using complex models based on differential equations (which are used to estimate the energy consumed by a building). In this work, we propose a systematic framework for the design of buildings that combines a rigorous objective reduction method (which removes redundant objectives from the analysis) with a surrogate model (which simplifies the calculation of the energy requirements of the building), both of which expedite the identification of alternative designs leading to environmental improvements. The capabilities of our methodology are illustrated through a case study based on a thermal modelling of a house-like cubicle, in which we optimize the insulation thicknesses of the building envelope. Results show that significant economic and environmental improvements can be achieved compared to the base case (cubicle without insulation). Furthermore, it is clearly illustrated how the minimization of an aggregated environmental metric, like the Eco-Indicator 99, as unique environmental objective may overlook some Pareto solutions that may be appealing for decision-makers. The authors would like to acknowledge financial support from the Spanish Government (ENE2015-64117-C5-3-R (MINECO/FEDER, UE)). Joan Carreras would also like to acknowledge financial support from the Pump-Priming Research Programs of The University of Manchester.