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As the Prime Minister calls on all who can go back to work to do so, what is needed to make our buildings safe and ready?

Newspapers are publishing images of empty cities to show just how much life has changed now that millions of workers who normally flock to offices each day are working from home.

It’s strange to see once-teeming streets now uninhabited.  While we might think of cities in terms of their buildings or roads, they are in reality made dynamic by the people who live and work there.  

But those of us who know building services know that many of the offices and other buildings aren’t entirely empty.

Somewhere in those buildings are facilities and maintenance teams trying to ensure that even mothballed properties continue to meet statutory health and safety requirements.

And that the space will be safe for occupants once the return to normality begins.

REHVA strongly recommends that recirculation of air is avoided

Karen Fletcher Karen Fletcher Former editor of CIBSE Journal and MBS magazine

Buildings vary, so will returning

In its recent report on reopening workplaces, property developer Cushman & Wakefield noted: “The migration of the workforce back to places of business will look different for every organisation.

The mix of returning employees will vary and in some cases a segment of the workforce may continue to work remotely. One thing is clear, however – the management of the process is without precedent.”

The World Health Organisation (WHO) has produced its own guidance** on preparing the workplace for a healthy return to work (see link below). This offers good insights into how to support the workforce to remain vigilant and aware so that risks are mitigated.

Building services such as ventilation, cooling, heating and water systems play a central role in the health and safety (and comfort) of occupants.

Guidance offered

And for buildings which are currently mothballed some of the leading organisations have offered guidance with a focus on our sector.

The REHVA (Federation of European Heating, Ventilation and Air Conditioning Association) COVID-19 Guidance Document (3rd April 2020) offers its insights into operating and using building services to prevent the spread of coronavirus.

As the document states: “The guidance is focused to temporary, easy-to-organise measures that can be implemented in existing buildings which are still in use with normal occupancy rates. The advice is meant for a short period, depending on how long local outbreaks last.”

In other words, the guidance is aimed at minimising the risk of Covid-19 in buildings that are occupied as usual.

Increase fresh air

There are a number of key areas addressed by REHVA, including increasing air supply exhaust and ventilation.

In general, the message is to supply as much outside air as possible to optimise the amount of fresh air supplied per person. 

REHVA recommends that in buildings with mechanical ventilation systems, the operating times are extended – from two hours before daily building occupation until two afters after occupants leave.

For demand controlled ventilation, REHVA says that the CO2 setpoint should be set to 400ppm with ventilation on 24/7 – with ventilation lowered but not off when the building is unoccupied.  Exhaust systems in toilets (identified as areas with high potential for infection) should remain on 24/7, with under-pressure.

Avoid recirculation

REHVA strongly recommends that recirculation of air is avoided. Recirculation dampers should be closed. This may cause some discomfort to occupants, but it is noted in the guidance that in the current outbreak, health is more important than thermal comfort.

One point to note about REHVA guidance is that the Federation says that although relative humidity and temperature can generally contribute to virus transmission indoors, they do not seem to have an impact on COVID-19.  

It seems that studies so far indicate the virus is quite resistance to environmental changes.

So current advice is that in buildings with centralised humidification there is no need to change set points on these systems. This means that heating and cooling systems can operate normally, according to REHVA’s latest advice.

More to learn

An important point that leading organisations are making is that COVID-19 is still not fully understood, and that changes in our knowledge will offer more insights into making buildings safer.

Facilities managers and building services maintenance teams will need to ensure that they are aware of changes in guidance and best practice.

Beyond health and safety issues, the post-COVID world might leave some office-based businesses considering how they use space in future.  It might be tempting to reduce floor space and have more staff work remotely.

We have all been forced to take the leap into working from home and into the world of Zoom meetings and Skype calls, so it would seem less strange in the long-term.

But while many will be enjoying the lack of commute, there are other challenges such as slow internet and the loss of general interaction with colleagues (gossip round the coffee machine not being quite the same at home).

My guess is that in future, while we might be inclined to avoid long drives to meetings by using video tech instead, we might just all come back with a greater appreciation of office life.

Karen Fletcher is Content Director of Rocket Content and a former editor of CIBSE Journal and MBS magazine