Dataset of an in-use tertiary building collected from a detailed 3D mobile monitoring system and building automation system for indoor and outdoor air temperature analysis

[EN] A Mobile Monitoring System (MMS) has been designed tak- ing into account the use of technology with high sensor ac- curacy and the ability to be installed easily and quickly in different cardinal locations, distribution spaces, volumes and at different heights of a tertiary in-use building located in Leioa (Bilbao). Two types of MMS have been designed with the objective of carrying out two types of analysis; one in- tended to do a global indoor air temperature uncertainty analysis and the other focused on doing a global outdoor air temperature uncertainty analysis. Eight tripods make up the interior MMS with twenty sen- sors at different heights, which have been installed in differ- ent offices in the building to collect indoor air temperature measurements at different heights and locations. In addition, eight sensors make up the exterior MMS to collect data from outdoor air temperature measurements around the building envelope. Both MMS have been integrated into the existing Building Automation System (BAS) of the tertiary building; some other data collected by the BAS has also been taken into account for the uncertainty analysis of indoor and out- door air temperature. The interior and exterior MMS datasets have been compiled based on a rigorous data collection process, with the po- tential to use the data to study the spatial air temperature behavior, taking into account the impact of solar radiation, the heating system and the electrical energy consumption. Furthermore, it enables the global uncertainty of indoor and outdoor air temperature measurements on an in-use build- ing to be estimated and to break it down into the differ- ent uncertainty sources, such as the sensor accuracy, vertical and horizontal temperature variability, solar radiation, occu- pancy and heating system effects. Finally, it enables the opti- mization of monitoring and control systems for BAS, heating and HVAC systems, as well as any monitoring system imple- mented in research tests using indoor and/or outdoor tem- perature measurements as key variables

Comparison between Energy Simulation and Monitoring Data in an Office Building

One of the most important steps in the retrofitting process of a building is to understand its pre-retrofitting stage energy performance. The best choice for carrying this out is by means of a calibrated building energy simulation (BES) model. Then, the testing of different retrofitting solutions in the validated model allows for quantifying the improvements that may be obtained, in order to choose the most suitable solution. In this work, based on the available detailed building drawings, constructive details, building operational data and the data sets obtained on a minute basis (for a whole year) from a dedicated energy monitoring system, the calibration of an in-use office building energy model has been carried out. It has been possible to construct a detailed white box model based on Design Builder software. Then, comparing the model output for indoor air temperature, lighting consumption and heating consumption against the monitored data, some of the building envelope parameters and inner building inertia of the model were fine tuned to obtain fits fulfilling the ASHRAE criteria. Problems found during this fitting process and how they are solved are explained in detail. The model calibration is firstly performed on an hourly basis for a typical winter and summer week; then, the whole year results of the simulation are compared against the monitored data. The results show a good agreement for indoor temperature, lighting and heating consumption compared with the ASHRAE criteria for the mean bias error (MBE).This research was supported by the A2PBEER project “Affordable and Adaptable Public Buildings through Energy Efficient Retrofitting” under grant number 609060 funded by the European Commission for providing resources for the monitoring system. The APC was funded by the Spanish Ministry of Science, Innovation and Universities and the European Regional Development Fund through the project called “Investigation of monitoring techniques of occupied buildings for their thermal characterization and methodology to identify their key performance indicators”, project reference: RTI2018-096296-B-C22 (MCIU/AEI/FEDER, UE)

A PC-tool to calculate the Moisture Buffer Value

Hygroscopic building materials have the ability to moderate the relative humidity variation without the need for active systems. The moisture buffer phenomenon can be assessed by way of the Moisture Buffer Value (MBV). Some authors have pointed out that the MBV is sensitive to several parameters, however, there is no model that involves all them. The aim of the developed PC-tool is to take into account all these variables to calculate the MBV of hygroscopic building materials. The material hygroscopic properties will be needed to solve the moisture storage and transport inside the porous materials and consequently to predict its MBV

Thermal characterization of a modular living wall for improved energy performance in buildings

Vertical vegetation systems are an innovative passive method for decreasing the thermal energy demand of buildings while increasing the quality of urban life. The main objective of this work is to calculate the effectiveness of vegetation in reducing thermal loads analytically. For this purpose, the thermal energy performance of the modular living wall was compared with a traditional double façade construction system to evaluate the influence of vegetation using Stochastic Differential Equations models. The research was carried out experimentally using a real-scale PASLINK test cell. The thermal behaviour of a double leaf bare wall and the same double leaf wall converted into a modular living wall were calculated for different summertime and wintertime periods. In both studied cases, the temperature of the exterior surface of the bare wall is taken at the same place regardless of whether or not there is greenery system in the energy balance. With this simplification, the effect of the modular living wall can be identified within the estimated coefficients. The thermal resistance of the conventional double façade increased 0.74 (m2 K)/W over the non-greened wall, which represents a weighted increase of 49%. Additionally, the experimental results showed that the evapotraspiration processes that take place in the living wall lead to an increase in the combined convection-radiation coefficient, which reduces the overheating of the façade. Moreover, the effective solar absorptivity value of the outermost surface of the bare wall has been reduced an 85% thanks to the living wall, which confirms the high capacity of the living wall to reduce solar heat gains.This publication is part of the R+D+i project PID2021-126739OB-C22, financed by MCIN/AEI/10.13039/501100011033/ and “ERDF A way of making Europe”. This project has been made possible thanks to the agreement between the Basque Government and the University of the Basque Country UPV/EHU through of the ENEDI research group for the management and development of the Thermal Area of the Buildings Quality Control Laboratory of the Basque Government (ATLCCE). Open Access funding provided by University of Basque Country

Energia-teknologia: taulak eta abakoak

Helburuak: Ikasmaterial honen helburu nagusiak honako hauek dira: Beroaren transmisioa irakasteko behar diren taula, abako eta korrelazio batzuk biltzea, ikasleak ikasturtean zehar irakasgaia hobeto jarrai dezan. Horretaz gain energia-teknologiako beste arlo batzuen (errekuntza, aire hezea eta hozte teknologia) taulak eta abakoak biltzea ere. Gai hauekin erlazionaturiko ariketa multzoa ere ageri da testuan emaitzekin. Norentzat: Industria Ingeniaritzako 4. mailako ikasleentzat. Baita Ingeniaritza Kimikoan Beroaren Transmisioa ikasten dabiltzan 2. mailako ikasleentzat, edota Industria Antolakuntzan bigarren zikloko lehenengo mailako ikasleentzat. 2010-11 ikasturtetik aurrera indarrean egongo diren gradu ikasketetan bigarren mailan irakatsiko den Termoteknia izeneko irakasgaian lagungarria ere izango da.Liburu honetan atal hauek agertzen dira: Unitateak eta bihurketa-faktoreak, beroaren transmisioa (konduzkioa, konbekzioa eta erradiazioa), errekuntza, aire hezea, hozte-makinak eta ariketak.Liburu honek UPV/EHUko Euskara eta Eleaniztasuneko Errektoreordetzaren dirulaguntza jaso d

Effect of Nd doping on the crystallographic, magnetic and magnetocaloric properties of NdxGd3-xCoNi

The crystal structure, magnetic and magnetocaloric properties, and the critical behavior of representative compounds in the pseudo-ternary NdxGd3-xCoNi series have been investigated (x = 0.15, 0.5, 1.0, 1.5). All these phases are isotypic with the parent compound Gd3CoNi, crystallizing with the monoclinic Dy3Ni2-type (mS20, C2/m, No. 12). All samples present a paramagnetic to ferromagnetic (PM-FM) second order phase transition with decreasing Curie temperature as the Nd concentration is increased (TC = 171 K, 150 K, 120 K and 96 K, respectively) and, at lower temperatures, there is a spin reorientation which leads to a complex magnetic ground state. The critical exponents (beta, gamma, delta) have been retrieved for the PM-FM transitions. On the one hand, in x = 0.15, 0.5, 1.5 the value of γ ≈ 1 indicates that the magnetic interactions are long-range order while the values of β point to a certain deviation from the 3D-Heisenberg universality class; on the other hand, NdGd2CoNi has a particular critical behaviour, as β is close to the Mean Field model while γ is close to the uniaxial 3D-Ising one. Concerning the magnetocaloric properties, the magnetic entropy change and refrigerant capacity present competitive values, interesting for cryogenic applications. Finally, the thermal diffusivity values of these compounds are extremely good for practical magnetocaloric refrigeration systems, as they are in the range 1.5-3 mm2/s.This work has been supported by Departamento de Educación del Gobierno Vasco (Project No. IT1430-22)

Orientation-Constrained System for Lamp Detection in Buildings Based on Computer Vision

Computer vision is used in this work to detect lighting elements in buildings with the goal of improving the accuracy of previous methods to provide a precise inventory of the location and state of lamps. Using the framework developed in our previous works, we introduce two new modifications to enhance the system: first, a constraint on the orientation of the detected poses in the optimization methods for both the initial and the refined estimates based on the geometric information of the building information modelling (BIM) model; second, an additional reprojection error filtering step to discard the erroneous poses introduced with the orientation restrictions, keeping the identification and localization errors low while greatly increasing the number of detections. These enhancements are tested in five different case studies with more than 30,000 images, with results showing improvements in the number of detections, the percentage of correct model and state identifications, and the distance between detections and reference positions.Authors want to give thanks to the Xunta de Galicia under Grant ED481A and the Spanish Ministry of Economy and Competitiveness under the National Science Program TEC2017-84197-C4-2-R

Defining the cooling and heating solar efficiency of a building component skin: application to a modular living wall

[EN] The thermal evaluation of building components composed of a base wall with a solar passive skin solution, such as a vertical/roof greenery system, ventilated facade, reflective painting, etc., is usually performed as a whole. In this research, it has been proven that, independently of the base wall thermal inertia and insulation level, the temperature of the outermost surface layer of any building component during sunny hours is mainly dependent on the ambient air temperature and relative humidity, the incident global solar radiation and the building skin behaviour. The latter assumption has been proven on the south wall of a reference building simulated with TRNSYS. The south wall properties have been varied and the building has been subjected to different climates. The assumption's validity has been checked for twelve south wall cases: a combination of 2 thermal transmittance, 2 thermal inertia and 3 climates. Each case has been simulated for a whole year. Based on this finding and the local ambient conditions for sunny hours, the hypothetical achievable maximum and minimum temperatures for the outermost surface layer have been defined. Then, based on the outermost surface temperature experimental measurements, the cooling and heating solar efficiencies valid for any skin solution have been defined. Furthermore, the developed methodology has been applied to a vertical living wall tested for a whole year under the accuracy and quality procedure of the PASLINK method. In this way, the cooling and heating solar efficiencies were experimentally determined for this skin solution for both, the hot cold seasons. The study has shown that the cooling efficiency during the hot season is 90.8%. As expected, even during sunny summer hours, the presence of water positively affects the performance of the facade, as it brings the base wall external surface temperature close to the ambient wet bulb temperature, therefore reducing the cooling load of the building. For the cold season, the cooling efficiency was similar, at 90.3%, which means a heating efficiency of 9.7%. Again, even for sunny winter hours, the values of the external surface temperature tend towards the ambient air wet bulb temperature, resulting in an increase in the heating demand. These experimental efficiency values allow the heating or cooling behaviour of different skin solutions to be comparable with a single number that is independent of the base wall composition. In addition, independently of the base wall composition, once the experimental efficiency value of a given skin solution is known, it allows (during sunny hours) the base wall outermost surface temperature to be calculated with precision. The latter makes it possible to increase the accuracy of the estimation of the heating and cooling demands of such methods as the degree-day method.This work was supported by the Spanish Ministry of Science, Innovation and Universities and the European Regional Development Fund (grant number RTI2018-096296-B-C22) through the MONITHERM project 'Investigation of monitoring techniques of occupied buildings for their thermal characterization and methodology to identify their key performance indicators', project reference: RTI2018-096296-B-C22 (MCIU/AEI/FEDER, UE). Open Access funding provided by University of Basque Country

A Functional Data Analysis for Assessing the Impact of a Retrofitting in the Energy Performance of a Building

There is an increasing interest in reducing the energy consumption in buildings and in improving their energy efficiency. Building retrofitting is the employed solution for enhancing the energy efficiency in existing buildings. However, the actual performance after retrofitting should be analysed to check the effectiveness of the energy conservation measures. The aim of this work was to detect and to quantify the impact that a retrofitting had in the electrical consumption, heating demands, lighting and temperatures of a building located in the north of Spain. The methodology employed is the application of Functional Data Analyses (FDA) in comparison with classic mathematical techniques such as the Analysis of Variance (ANOVA). The methods that are commonly used for assessing building refurbishment are based on vectorial approaches. The novelty of this work is the application of FDA for assessing the energy performance of renovated buildings. The study proves that more accurate and realistic results are obtained working with correlated datasets than with independently distributed observations of classical methods. Moreover, the electrical savings reached values of more than 70% and the heating demands were reduced more than 15% for all floors in the building.This paper was funded by the Spanish Government (Science, Innovation and Universities Ministry) under the project RTI2018-096296-B-C21

Estimation of the Heat Loss Coefficient of Two Occupied Residential Buildings through an Average Method

The existing performance gap between the design and the real energy consumption of a building could have three main origins: the occupants’ behaviour, the performance of the energy systems and the performance of the building envelope. Through the estimation of the in-use Heat Loss Coefficient (HLC), it is possible to characterise the building’s envelope energy performance under occupied conditions. In this research, the estimation of the HLC of two individual residential buildings located in Gainsborough and Loughborough (UK) was carried out using an average method. This average method was developed and successfully tested in previous research for an occupied four-story office building with very different characteristics to individual residential buildings. Furthermore, one of the analysed residential buildings is a new, well-insulated building, while the other represents the old, poorly insulated semidetached residential building typology. Thus, the monitored data provided were filtered in order to apply the abovementioned average method. Even without fulfilling all the average method requirements for these two residential buildings, the method provides reliable HLC values for both residential buildings. For the house in Gainsborough, the best estimated HLC value was 60.2 W/K, while the best approach for Loughborough was 366.6 W/K. Thus, despite the uncertainty sources found during the analysis, the method seems promising for its application to residential buildings.This work was supported by the Spanish Ministry of Science, Innovation and Universities and the European Regional Development Fund through the MONITHERM project “Investigation of monitoring techniques of occupied buildings for their thermal characterization and methodology to identify their key performance indicators”, project reference: RTI2018-096296-B-C22 and -C21 (MCIU/AEI/FEDER, UE)