Accurate design and sizing crucial for ‘healthy’ AHUs

The role of ventilation systems in minimising health problems in buildings has been under the microscope this year. Leading medical experts have long recognised the importance of good ventilation in helping to safeguard the health and wellbeing of building occupants – and especially the most vulnerable – but this topic has assumed even greater significance during the COVID-19 crisis. The UK’s Deputy Chief Medical Officer, Professor Jonathan VanTam, was particularly clear about this during a press briefing in April, when he said: “There is a definite truism across all of the science literature, that ventilation is a most critical part of reducing transmission from respiratory viruses.”

By the same token, there was also a lot of early confusion about the potential for ventilation systems to spread the virus, which could have been very damaging if facilities managers in critical buildings had decided that the safest course of action was to switch systems off.

However, the technical guidance issued by the various UK and European industry bodies took a consistent line, and demonstrated that these systems were not the problem and, in fact, should be seen as a key part of the solution. The HVAC sector as a whole continued to perform a crucial role in keeping essential services like hospitals, supermarkets, care homes, and schools, operating throughout the crisis. Ventilation systems are, of course, going to be even more important as the lockdown restrictions are lifted, and buildings start to re-open.