Thermal comfort is determined by the combined effect of the six thermal comfort parameters: temperature, air moisture content, thermal radiation, air relative velocity, personal activity and clothing level as formulated by Fanger through his double heat balance equations. In conventional air conditioning systems, air temperature is the parameter that is normally controlled whilst others are assumed to have values within the specified ranges at the design stage. In Fanger’s double heat balance equation, thermal radiation factor appears as the mean radiant temperature (MRT), however, its impact on thermal comfort is often ignored. This paper discusses the impacts of the thermal radiation field which takes the forms of mean radiant temperature and radiation asymmetry on thermal comfort, building energy consumption and air-conditioning control. Several conditions and applications in which the effects of mean radiant temperature and radiation asymmetry cannot be ignored are discussed. Several misinterpretations that arise from the formula relating mean radiant temperature and the operative temperature are highlighted, coupled with a discussion on the lack of reliable and affordable devices that measure this parameter. The usefulness of the concept of the operative temperature as a measure of combined effect of mean radiant and air temperatures on occupant’s thermal comfort is critically questioned, especially in relation to the control strategy based on this derived parameter. Examples of systems which deliver comfort using thermal radiation are presented. Finally, the paper presents various options that need to be considered in the efforts to mitigate the impacts of the thermal radiant field on the occupants’ thermal comfort and building energy consumption.
Current symptom detection methods for energy diagnosis in heating, ventilation and air conditioning (HVAC) systems are not standardised and not consistent with HVAC process and instrumentation diagrams (P&IDs) as used by engineers to design and operate these systems, leading to a very limited application of energy performance diagnosis systems in practice. This paper proposes detection methods to overcome these issues, based on the 4S3F (four types of symptom and three types of faults) framework. A set of generic symptoms divided into three categories (balance, energy performance and operational state symptoms) is discussed and related performance indicators are developed, using efficiencies, seasonal performance factors, capacities, and control and design-based operational indicators. The symptom detection method was applied successfully to the HVAC system of the building of The Hague University of Applied Sciences. Detection results on an annual, monthly and daily basis are discussed and compared. Link to the formail publication via its DOI https://doi.org/10.1016/j.autcon.2020.103344
Peer-to-peer (P2P) energy trading has been recognized as an important technology to increase the local self-consumption of photovoltaics in the local energy system. Different auction mechanisms and bidding strategies haven been investigated in previous studies. However, there has been no comparatively analysis on how different market structures influence the local energy system’s overall performance. This paper presents and compares two market structures, namely a centralized market and a decentralized market. Two pricing mechanisms in the centralized market and two bidding strategies in the decentralized market are developed. The results show that the centralized market leads to higher overall system self-consumption and profits. In the decentralized market, some electricity is directly sold to the grid due to unmatchable bids and asks. Bidding strategies based on the learning algorithm can achieve better performance compared to the random method.
Due to the existing pressure for a more rational use of the water, many public managers and industries have to re-think/adapt their processes towards a more circular approach. Such pressure is even more critical in the Rio Doce region, Minas Gerais, due to the large environmental accident occurred in 2015. Cenibra (pulp mill) is an example of such industries due to the fact that it is situated in the river basin and that it has a water demanding process. The current proposal is meant as an academic and engineering study to propose possible solutions to decrease the total water consumption of the mill and, thus, decrease the total stress on the Rio Doce basin. The work will be divided in three working packages, namely: (i) evaluation (modelling) of the mill process and water balance (ii) application and operation of a pilot scale wastewater treatment plant (iii) analysis of the impacts caused by the improvement of the process. The second work package will also be conducted (in parallel) with a lab scale setup in The Netherlands to allow fast adjustments and broaden evaluation of the setup/process performance. The actions will focus on reducing the mill total water consumption in 20%.
One of the mission-driven innovation policies of the Netherlands is energy transition which sets, among others, the challenge for a carbon-neutral built environment in 2050. Around 41% of Dutch houses do not yet have a registered energy label, and approximately 31% of the registered houses have label C or lower. This calls for action within the housing renovation industry. Bound to the 70 percent rule, a renovation plan requires full (or at least 70 percent) agreement on the renovation between relevant parties, including residents. In practice, agreement indicators focus mostly on economic and energy aspects. When indicators include people’s needs and preferences, it is expected to speed participation and agreement, increasing residents’ satisfaction and enhances the trust in public institutions. Tsavo was founded in 2015 to organise the sustainability of buildings for ambitious clients. Its sustainability process aims to accelerate renovation by keeping at their core value the social needs and preferences of residents. In this project Tsavo and TU Delft work together to optimise the sustainability process so, it includes everyone’s input and results in a sustainability plan that represents everyone. Tsavo’s role will be key in keeping the balance between both a sustainable renovation service that is cheaper and fast yet also attractive and with an impact on the quality of living. In this project, Tsavo’s sustainable renovation projects will be used to implement methods that focus on increasing participation and residents’ satisfaction. TU Delft will explore principles of attractive, accessible and representative activities to stimulate residents to decide on a renovation plan that is essential and meaningful to all.
Als gevolg van de energietransitie wordt het steeds moeilijker om energieaanbod en -vraag op elkaar af te stemmen en ontstaan problemen op het elektriciteitsnet. Energieopslag biedt een oplossing: duurzame energie wordt opgeslagen op momenten dat er aanbod en weinig energievraag is en beschikbaar gesteld wanneer er weinig aanbod en veel vraag is. Lokale opslag biedt een kans om lokale uitval van het elektriciteitsnet te voorkomen en geeft meerwaarde aan duurzame energie. Opslag in waterstof is uitermate geschikt voor zowel toepassingen op MW-schaal (windparken), voor seizoensopslag en voor toepassingen waar distributie relevant is. De wens van bedrijventerreinen om te verduurzamen biedt een kans om gericht aan oplossingen voor lokale energieopslag in waterstof en bijbehorende toepassingen te werken. In dit project werkt de HAN samen met MKB-bedrijven, Saxion, TU Delft, lokale overheden en een aantal overige partners aan het ontwikkelen en optimaliseren van een energieopslagsysteem gebaseerd op waterstof en bijbehorende waterstoftoepassingen op en voor bedrijventerrein IPKW in Arnhem. Beschikbare windenergie van in aanbouw zijnde turbines langs de Rijn bij IPKW vormen de aanleiding voor het ontwerpen, modelleren, construeren en testen van een (geschaald) energieopslagsysteem gebaseerd op de productie, en opslag van waterstof. Specifieke toepassingen op het industriepark worden geïnventariseerd, en waar mogelijk gerealiseerd en gemonitord, voor met name lokaal bedrijfstransport en elektriciteitslevering. Scenario’s voor ontwikkeling en toepassing van de technologie ontwikkeld en haalbaarheidsstudies uitgevoerd. Kennis en expertise worden ontwikkeld om het proces van optimale implementatie van waterstof voor energieopslag in een energieketen met specifieke toepassingen op een bedrijventerrein te ondersteunen. Met dit project bouwen wij voort op de vele eerdere waterstofprojecten die bij de HAN zijn uitgevoerd en maken we gebruik van ons recent gerealiseerde shared facility HAN Waterstoflab op IPKW.
