• Energy Research

Current and best practices for hybridGEOTABS design and control around Europe are described in this report. It provides an overview of the design of a hybridGEOTABS building and the core modules, and an overview of the latest developments for controlling integrated building systems using MPC. The report provides an overview of the state-of-the-art hybridGEOTABS design and control during the hybridGEOTABS project and allows to understand the issues various stakeholders are facing, for which solutions are developed in the hybridGEOTABS project. This project has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No. 723649

Radiant cooling systems are a subject of increasing scientific interest due to their efficiency and ability to use high-temperature cooling sources. In hot and humid conditions, they have generally been studied in combination with dehumidification systems. For retrofit projects, a control system that would eliminate the need for dehumidification would be beneficial. In the present study, a passive geothermal-based radiant high-temperature cooling system is studied in a Mediterranean climate. The system is operated with supply water temperature control using dew point temperature as a controlling variable. The system's performance is compared with that of an all-air cooling system. The systems are evaluated using IDA-ICE building energy simulations, validated with on-site measurement data. The results show that the radiant cooling system produces the same level of thermal comfort with 40% lower energy use and 85% lower exergy consumption than the all-air system. The risk of condensation limits the cooling capacity of the radiant cooling system. Consequently, insufficient cooling capacity causes thermal discomfort for the occupants due to the operative temperature exceeding 26 °C. Datasets: "Building energy simulation data results" and "Acquired data from existing and/or new installed meters or from existing BEMS (pre intervention EcoSCADA monitoring data)" - Raw data is available upon request. Follow the link and fill the request form.

Abstract In recent years, the increasing occurrence of heatwaves raises the cooling need of residential buildings in Scandinavian countries, which are traditionally not equipped with active cooling systems. Indoor overheating caused by such heatwaves leads to severe consequences for occupants, especially kids and seniors. Efficient and economical cooling solutions are urgently needed to cope with frequent heatwaves. The present study investigated the novel usage of the geothermal-assisted mechanical ventilation with heat recovery (GEO-MVHR) system for cooling purposes in typical Swedish multi-family dwellings. The cooling potential of the system and its contributions to thermal comfort were evaluated. Dynamic simulations were conducted to assess the system's cooling performance under two climate scenarios: the climate of 2018 representing an extreme year with excessively hot summer and the climate of a typical meteorological year. The GEO-MVHR system shows great potential in mitigating indoor overheating with improved thermal comfort. A ventilation airflow rate of 0.50–0.70 l/s/m2 is suggested for multi-family dwellings to maximize the cooling potential of the GEO-MVHR system. The indoor operative temperature could be reduced by up to 3 °C with the GEO-MVHR system operating for cooling. Modulating the supply air temperature of the GEO-MVHR system based on indoor thermal conditions is recommended, as it shows the advantage of avoiding unnecessary overcooling and energy saving.

This study evaluated the impacts of radiator designs and geometries. The aim was to map the thermal efficiency and performance differences of studied radiator types. A typical Swedish low-rise mul ...

Building energy management systems (BEMSs), dedicated to sustainable buildings, may have additional duties, such as hosting efficient energy management systems (EMSs) algorithms. This duty can become crucial when operating renewable energy sources (RES) and eventual electric energy storage systems (ESSs). Sophisticated EMS approaches that aim to manage RES and ESSs in real time may need high computing capabilities that BEMSs typically cannot provide. This article addresses and validates a fuzzy logic-based EMS for the optimal management of photovoltaic (PV) systems with lead-acid ESSs using an edge computing technology. The proposed method is tested on a real smart grid prototype in comparison with a classical rule-based EMS for different weather conditions. The goal is to investigate the efficacy of islanding the building local network as a control command, along with ESS power control. The results show the implementation feasibility and performance of the fuzzy algorithm in the optimal management of ESSs in both operation modes: grid-connected and islanded modes.

Abstract This research explored the importance of airflow rate and convector plate design on the operational performance of heating radiators equipped with an air device (ventilation radiators). The radiator was analyzed according to European Norm EN 442-2 using numerical simulations. The largest benefit of using staggered convector plates was the more efficient preheating of the incoming outdoor air supply. With this plate design, the evaluated radiator increased the temperature of the incoming airflow of 10 l/s from -5 °C to 26 °C with water supply/return temperatures of 45 °C/35 °C. With these water temperatures, the radiator was able to cover a room heat loss of 34 W/m2 floor area. However, the design of the convector plate alone was found to have a limited impact on the heat output from the radiator. Neither did the plate design significantly affect the uniformity of heat distribution nor the vertical temperature stratification inside the room. The results also showed that ventilation radiators might cover a building heating load (kW) with a lower supply water temperature but not necessarily give a lower annual energy use (kWh) for the space heating of a building.

Frosting is a common problem in air handling units in buildings in cold climates. Tacklingthis problem is so far achieved by using considerable amount of energy while during thisprocess, the indoor ...

This study investigated the thermal potential of two renewable heat sources, residential wastewater and geothermal energy, for preheating the incoming air to the air-handling unit (AHU) in a multi-family building. The main purpose of preheating the inlet air was to avoid the frost formation inside AHU due to low outdoor temperatures during winter. Wastewater extraction flowrate and temperature, as two design parameters, were studied in detail by employing two types of wastewater storage tanks.

Sweden is actively engaged in accelerating the sustainable transformation of existing building and energy systems. Most traditional investigations of this subject have been based on final energy sa ...

AbstractThis paper presents the modeling results of combining low temperature heating (ventilation radiator) with ventilation energy- demand savings. Investigations on operational energy and thermal comfort are in focus.IDA ICE is employed to investigate the thermal performance and energy usage. The results show that low temperature heating can reduce mean air temperature fluctuations in the selected archetype. When combining low temperature heating with ventilation and air-tightness renovations, the thermal performance of the heating system can be largely improved to an acceptable level. The retrofitting strategy can save 41% of heating energy demand and 27% of total primary energy.