TEMPORARY HEALTHCARE FACILITIES | CAREBOX Arup is sharing the guidelines freely so facilities can be implemented when they are needed from an existing healthcare site or have to be supplied as part of a modular bolt on. It also means that when the facilities are no longer needed, they can be taken apart and redeployed elsewhere or put into storage. Or it could be used as a legacy project for the community, particularly in lower-resource type situations or countries where the healthcare system may be short of beds. Moran says the CareBox designs are adaptable enough to evolve as understanding of potential airborne transmission of the virus increases. With CFD analysis and modelling, you can see where the airflow is going within spaces, and where you may have a concentration of pathogen because of poor airflow. Once you have that level of understanding, you can design low-tech solutions to help airflow, such as shunt fans or more ventilation. Were starting to look at the interactions for CareBox to introduce a little more sophistication into what that analysis might be, and how it could work. Responses As healthcare organisations cope with the second wave of Covid-19, the demand for CareBox-type solutions may depend on the type of responses authorities take and whether smaller, more localised solutions, rather than large-scale Nightingale-type facilities, may be necessary. Although it has yet to be deployed in its modular form, Moran says Arup has been in discussions about possible adoption of CareBox solutions with several NHS healthcare trusts in the UK and various healthcare organisations in South America. He says: The Nightingale Hospital-type solutions provided effective surge capacity as the starting point. However, health authorities are now looking for more resilient solutions to enable them to deal with Covid patients, while maintaining care and treatment of other patient cohorts. This is particular evident as health authorities assess the likely impacts of the next wave of Covid-19. Arup has taken an open-source approach to CareBox and is sharing the guidelines freely so facilities can be implemented across communities when they are needed. CJ Each ward module can accommodate five moderate or severe Covid-19 patients UNIVERSITY CHALLENGES Two University of Cambridge academics have developed a series of low-tech ventilation and ward configuration solutions that they claim can significantly reduce the dispersal of airborne virus in buildings that have been converted into emergency Covid-19 healthcare facilities. Professor Andrew Woods, of Cambridges BP Institute, and Professor Alan Short, of the Department of Architecture, say the type of large air-conditioned halls that have been rapidly converted into emergency hospital facilities tend to feature top-down air conditioning, which creates turbulent flows that can mix and spread droplets containing the virus very widely. Their research (shown in a video report at bit.ly/CJNov20CB) suggests that, with six changes of the air in the occupied part of the hall in an hour, it may take more than 20 minutes to dilute the concentration of smaller droplets produced in a cough to below a tenth of their original density. This creates a hazardous environment for healthcare workers as they pass through a slowly refreshing miasma. Effective ventilation is critically important in helping to suppress cross-infection, and nowhere more so than in an infectious diseases ward, explains Short, adding: Our research shows that a small number of straightforward modifications would reduce risk in what is already a very risky environment. The Cambridge teams recommendations are based on physical laboratory experiments to test ventilation systems for two basic bed arrangements: a typical open hall with hundreds of beds with low-level partitions; and with beds arranged within enclosed patient bays, partitioned at the side and sealed above (such as with polythene) so that, as far as possible, the exhaust air does not permeate the rest of the hall. In the open-hall scenario, the movement of the ventilation air means that, when a patient coughs or releases aerosols, the flow pattern of the aerosols can extend across the space to other patient beds. In the enclosed patient bays with exhaust ducts located behind the patients beds, aerosols from coughs potentially spreading the virus are contained within the space, and the high levels of aerosols retained there are rapidly removed by the ducts, minimising the spread of virus into the main ward space. The services configuration proposed by the Cambridge team sees contaminated air drawn from the exhaust ducts collected in dirty corridors running laterally across the facility before being discharged from the building. In this way, the spread of the virus can be minimised in the main areas between bays and clean corridor spaces that healthcare workers can use within the facility. The solution has been designed to be suitable for a variety of climates and the Cambridge team is currently working with Professor LS Shashidhara from Ashoka University, an adviser to the Indian government, and architect CS Raghuram, to create viable conversions of marriage halls and sheds as emergency Covid-19 hospitals in India. 32 November 2020 www.cibsejournal.com CIBSE Nov2020 p30-32 CareBox.indd 32 23/10/2020 15:49