Background
The operating room (OR) department is one of the most energy-intensive departments of a hospital. The majority of ORs in the Netherlands have an air-handling installation with an ultra-clean ventilation system. However, not all surgeries require an ultra-clean OR.

Aim
To determine the effect of reducing the air change rate on the ventilation effectiveness in ultra-clean ORs.

Methods
Lower air volume ventilation effectiveness (VELv) of conventional ventilation (CV), controlled dilution ventilation (cDV), temperature-controlled airflow (TcAF) and unidirectional airflow (UDAF) systems were evaluated within a 4 × 4 m measuring grid of 1 × 1 m. The VELv was defined as the recovery degree (RD), cleanliness recovery rate (CRR) and air change effectiveness (ACE).

Findings
The CV, cDVLv and TcAFLv ventilation systems showed a comparable mixing character in all areas (A, B and AB) when reducing the air change rate to 20/h. Ventilation effectiveness decreased when the air change rate was reduced, with the exception of the ACE.
At all points for the UDAF-2Lv and at the centre point (C3) of the TcAFLv, higher RD10Lv and CRRLv were measured when compared with the other examined ventilation systems.

Conclusions
The ventilation effectiveness decreased when an ultra-clean OR with an ultra-clean ventilation air-supply system was switched to an air change rate of 20/h. Reducing the air change rate in the OR from an ultra-clean OR to a generic OR will reduce the recovery degree (RD10) by a factor of 10–100 and the local air change rate (CRR) by between 42% and 81%.@en

This article investigates the efficacy of temperature-controlled airflow systems in modern operating rooms for contaminant control, a critical factor in preventing surgical site infections. We have conducted experimental measurements in an operating room equipped with temperature-controlled ventilation to map the airflow field and contaminant dispersion (airborne particles with diameters ranging from 0.5 to 1 μm). The results were used to validate the computational fluid dynamics code, which was then employed to simulate and examine different conditions, including contaminant release locations and air supply rates. Realizable k-epsilon and passive scalar models were utilized to simulate airflow and airborne particle phases. We assessed the airflow distribution and contaminant dispersion, utilizing indices such as ventilation and air change efficiency scales. The analysis provided quantitative insights into the distribution and removal of contaminants, as well as the speed at which the room air was replaced. Contamination was found to be effectively reduced when contaminants were released near exhaust outlets or under central unidirectional inlets. The presence of the operating table caused a big distortion of the central downward airflow, forming a horizontal air barrier at the periphery. Under this unique interior configuration, an appropriate air supply ratio between central and periphery zones was required to achieve optimal overall ventilation performance.@en

Ultra-clean ventilation systems are used in the operating room (OR) to reduce the quantity of airborne bacteria in the ultra-clean area, and reduce the incidence of surgical site infections (SSIs). When the number of colony-forming units (CFUs) in the ultra-clean (protected) area is too high, this is considered a risk factor for SSIs.@en

This study presents a systematic review of the literature on decision support for designing hospital layouts using spatial network analysis and/or simulation modelling. The review includes 102 articles, which are classified into five different categories concerning their layout-related challenges. Specifically, the categories include overcrowding, patient waiting times, visibility & staff interaction, wayfinding & walkability, and other issues such as hospital-acquired infections. The main finding is the cross-referenced table of different performance issues related to the hospital layout to different assessment methods, indicators, and quality criteria. The review suggests prospects for associating hospital design problems/challenges with spatial layout, as well as a framework for developing methods for layout representation, aggregation and relativization borrowing from the fields of transport planning and operations research. The main focus of this study lies in the spatial layout. Viewing the spatial complexity of a hospital as an indoor spatial environment is at least as complex as an urban environment, thus justifying a geographical approach; hence we expand the scope of the literature review to papers that may not directly address hospital design but have relations to spatial decision support systems.

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When making a decision on the operating room air handling installation and type of air supply system, it is relevant to know the expenditures of the different air handling installations and air supply systems. The aim of this study was to determine the capital and operational expenditures of air handling installations equipped with an ultra-clean or with a conventional system. To compare the technical requirements of Dutch air handling installations with European standards and guidelines, and evaluate the costs of surgical site infections in comparison with the capital expenditures. This study fills a gap in knowledge, detailed technical information and costs of air handling installations and air supply systems from multiple completed projects of 24 hospitals were collected, analyzed and compared. Per OR capital expenditures increase by €62,491 to €139,018 when an air handling installation with an ultra-clean system is compared to a conventional system, which is 3%–7% of the total construction costs of a completely new OR department. The yearly increase in operational expenditures per OR with an ultra-clean system compared to a conventional system was €673 to €1,896. The capital and operational expenditures of air handling installations with an ultra-clean system are higher than those with a conventional system. The technical specifications of the ORs studied in the Netherlands correspond to European standards and guidelines. When the impact on patient suffering and costs associated with surgical site infections are weighed against the investment required for an air handling installation with an ultra-clean system, it is worth considering.

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This research gives an overview of the current comfort and energy performance, and optional future design of highly transparent and lightweight buildings. The transparent Co-Creation Centre in the Green Village at the TU Delft, has a combination of active and passive climate control measures. The aim of the research is to show how transparent buildings with a high glass/floor percentage (here 122 %) perform and how these could be optimized. An overview of the research project and system integration is presented, with the focus on energy, comfort and working of the BMS-system. Energy and comfort performances are measured and simulated. Validation has been executed of daylight, solar heat access, and thermal performances. A large Phase Change Material (PCM) buffer in the air handling unit reduces the heating and cooling demand. Making use of passive qualities of the outdoor and indoor air temperature and solar energy requires a more complex control strategy than usual. A Model Predictive Control (MPC) strategy has been investigated and can optimize the energy consumption.@en

The authors regret that they have missed during the review process that the legend belonging to figure 6a, 6b, 6c and 6d is not shown. It is necessary to show the legenda otherwise the readers cannot interpret the graphs. Apologies that we missed it during the review process of the article. The legend belonging to figure 6 is:[Formula presented] The authors would like to apologize for any inconvenience caused.

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Background: Entrainment test methods are described in most European standards and guidelines to determine the protected area for ultra-clean ventilation (UCV) systems. New UCV systems, such as temperature-controlled airflow (TcAF) and controlled dilution ventilation (cDV) systems, claim the whole operating room (OR) to be ultra-clean. However, current test standards were not developed to assess ventilation effectiveness outside the standard protected area. Aim: To assess and compare the ventilation effectiveness of four types of OR ventilation systems in the ultra-clean area using a uniform test grid.
Methods: Ventilation effectiveness of four ventilation systems was evaluated for three different ultra-clean (protected) areas: the standard protected area (A); the area outside the standard protected area (B); and a large protected area (AB). Ventilation effectiveness was assessed using recovery degree (RD), cleanliness recovery rate (CRR) and air change effectiveness (ACE). Findings: RD, CRR and ACE were significantly higher for the unidirectional air flow (UDAF) system compared with the other systems in area A. In area B, the UDAF and cDV systems were comparable for RD and CRR, and the UDAF and conventional ventilation (CV) systems were comparable for ACE. In area AB, the UDAF and cDV systems were comparable for CRR and ACE, but significant differences were found in RD.
Conclusion: In area A, the ventilation effectiveness of the UDAF system outperformed other ventilation systems. In area B, the cDV system was best, followed by the UDAF, TcAF and CV systems. In area AB, the UDAF system was best, followed by the cDV, TcAF and CV systems. @en

The port of Rotterdam has been intertwined with the petrochemical industry for over a century. However, we are confronted today with the urgent necessity of transitioning away from fossil fuels and powering our energy and production systems with renewables. The Port of Rotterdam has a long-standing experience with hydrogen and as hydrogen can be the carrier of a circular energy transition, this is an opportunity for Rotterdam to become a major hub for the upcoming green hydrogen economy. Hydrogen can also be a disruptive circular economy technology and therefore an opportunity for facilitating a circular economy. There is no question about the main source of renewable energy: sun and wind deliver during one hour more energy than we need to power our societies worldwide for a year. Differences in availability in time and location, however, require means of storing the renewable energy harvested in sun and wind rich areas. Green hydrogen is one of the preferred candidates as an energy carrier because it is financially and logistically impossible to enlarge the electricity infrastructure to substitute the capacity of our natural gas infrastructure. Rotterdam can be an important hydrogen hub for Europe by reusing and upgrading its natural gas infrastructure, thereby contributing to the necessary transition towards a totally carbon free energy infrastructure in Europe.@en

Circular building has gained considerable attention in the Netherlands during the past decade. It is rooted in concepts such as circular economy (CE) and Cradle-to-Cradle (C2C®), accentuating the closing and coupling of material loops to establish effective and efficient resource flows. Moreover, those concepts adhere to a systemic, holistic worldview, incorporating multiple flows and values. Although social aspects, such as health, wellbeing, and social inclusiveness, are generally part of circular building principles, specific benefits for end-users are not. This paper explores the synergistic potential of circular and flexible (Circ-Flex) criteria from the perspective of enhanced control and convenience for residents. The hypothesis is that without integrating the user domain, replicability of circular building concepts on a larger residential scale cannot be done in a truly sustainable manner. The paper is structured around two objectives: (1) further identifying the relationship between flexible and circular building; and (2) exploring the impact of circular, flexible building concepts and practices for the users of multi-family housing, specifically regarding interior partitioning. The research follows a mixed-mode methodology comprising of literature review, case study, expert consultations and a quick-scan assessment. Eleven Circ-Flex criteria are explored, grouped in three categories: flexibility capacity, circularity capacity, and user capacity. These criteria are applied to two partitioning variants, whilst exploring the performance regarding material circulation and user benefits@en

This paper addresses the connection between circular building design and residential health and well-being. The general research objective is to determine assessment criteria for the performance of indoor partitioning products in a circular model. The overarching aim is to establish a more integrated and inclusive approach to the transition from linear to circular built environments. This ties in with recent calls for a more comprehensive evidence-base to better inform the policy debate, in the light of interrelated Sustainable Development Goals. The paper emphasises the operational level, looking closer at the actual performance of circular economy implementation, providing more grip on performance indicators of infill components in circular applications, specifically partition walls. Next to partitioning one can think of other components in the infill domain, such as kitchens, bathrooms and mechanical, electrical, plumbing installations. After a brief background sketch, a literature review is reported regarding indoor environmental quality and indoor air quality in general and the linkage with circular and flexible building (products) in particular. Next, an analysis is made of three assessment schemes that address the operational level. Subsequently, several criteria are synthesized and tested. It was shown that the assessment schemes have overlapping and complementary features that, in unison, provide a solid basis for an integrated assessment of circularity potential and health impact of infill products. The test-case helped to pinpoint generic, as well as case-specific, learning points. The interface between product performance and building performance over time remains a grey zone, insufficiently covered by current criteria. More stringent coordination efforts are essential to safeguard circularity potential and healthy living environments pre-use, post-use and not least in-use. @en

This article sheds light on the materialization and operation of residential partitioning wall components in relation to circular and flexible performance. The hypothesis is twofold: (1) A stronger integration of materialization and operation aspects is indispensable in establishing sustainable value-models, and (2) recent innovations, concerning the reversibility of material connections, will help disrupting the status-quo in that respect. Attention is drawn to renewable natural fibre composites (NFC), reversible adhesives, and biodegradable insulation materials. After a background sketch regarding the notion of time, change, and material circularity in design and planning, the housing challenge in the Amsterdam metropolitan area (AMA, the Netherlands) is described. Next, a design conceptualization stage is introduced, informed by two methods and tools in particular: Circ-Flex assessment, and activity-based spatial material flow analysis. Results of the conceptualization stage are presented regarding materialization and operation, culminating in Circ-Flex partitioning components, more specifically: Side panels and insulation. It was found that NFC can tackle current issues relating, most prominently, to circularity performance. Associated modifications in the value-chain occur, above all, in raw material sourcing, manufacturing, reutilization logistics, and data-sharing. The outcomes are valid for multiple building components other than indoor partitioning, such as kitchens and furniture, but also insulation—and interior side-sheeting—of walls and roofs in energy-renovations.@en

Waterstof is mogelijk een van de belangrijkste toekomstige dragers van een duurzame energievoorziening. De kringloop zon en water naar elektriciteit en water is elegant, duurzaam, niet-vervuilend en qua energiebron gratis. De Maatschappelijke AdviesRaad (MAR) van TVVL heeft de waterstofeconomie als speerpunt gedefinieerd. Een studiereis lag voor de hand, zowel in Nederland als in de UK (Leeds) lopen weliswaar initiatieven, maar er is nog weinig tot niets te zien. Vandaar dat wij verder gezocht hebben en in Duitsland terechtkwamen. Hier troffen wij een interessante combinatie van onderzoeksinstituten en bedrijfsleven, alle op het gebied van de waterstofeconomie. @en

In september 2016 is in het kader van een Rijksbreed programma Circulaire Economie1 een publicatie verschenen getiteld: ‘Nederland circulair in 2050’. Het is een gemeenschappelijke publicatie van – destijds – het Ministerie van Infrastructuur en Milieu, het Ministerie van Economische Zaken, mede namens het Ministerie van Buitenlandse Zaken en het Ministerie van Binnenlandse Zaken en Koninkrijksrelaties. De titel draagt reeds de uiterst ambitieuze doelstelling in zich die de auteurs voor ogen staat. Nederland moet zich ontwikkelen naar een circulaire economie en dat doel moet in 2050 bereikt zijn. Ik heb groot respect voor het inzicht en de moed van de betrokken medewerkers van de diverse ministeries om een dergelijk vergaand doel te formuleren. Nederland blinkt niet uit qua duurzaamheid en hier hebben we al de eerste vraag: hoe hangen duurzaamheid en circulariteit samen? Als we niet uitkijken, wordt het een linguïstische discussie in plaats van een ontwikkeling die er voor ons en ons nageslacht toe doet.@en

In onze traditioneel lineaire economie worden materialen gewonnen, verwerkt in producten en uiteindelijk gestort op stortplaatsen of verbrand in verbrandingsovens. Om de beschikking te kunnen blijven houden over materialen is een paradigmaverschuiving richting circulaire modellen onvermijdelijk. De bouwsector is voor een groot deel verantwoordelijk voor het totale materiaalgebruik. Ter illustratie: op Europees niveau wordt gemiddeld 37,5% van al het gebruikte hout toegepast in de bouw, 21% van al het staal, 65,5% van het glas en 75% van het beton [1]. Recycling is redelijk ingeburgerd in de bouw, maar vaak gaat dat gepaard met een aanzienlijk kwaliteitsverlies. Kennis, vaardigheden en technieken om hoogwaardige circulaire stromen te bewerkstelligen staan nog in de kinderschoenen.@en

Er is een massale, wereldwijde migratie van bevolking naar (groot)stedelijke gebieden. Volgens de Wereld gezondheidsorganisatie (WHO) was in 1960 nog slechts 34% van de wereldbevolking gehuisvest in steden terwijl dat naar verwachting in 2030 reeds 70% zal zijn [1]. Daarbij is de totale bevolking in deze periode toegenomen van 3 miljard naar bijna 9 miljard [2]. Dit betekent een enorme concentratie van mensen, sociale interacties, van creativiteit en dus van mogelijkheden. Aan de andere kant betekent dit evenzo: een concentratie van lucht- en watervervuiling, van logistieke problemen voor energie, voedsel en afval; kortom ook een groot aantal uitdagingen.@en