Providing Ventilation at John Radcliffe Hospital During the COVID-19 Crisis

Project Overview

In an effort to help contain the spread of COVID-19 within the John Radcliffe Hospital, RVT has devised a bespoke solution using the negative pressure principal to try and keep the virus contained within the wards that are housing patients who are suffering from suspected COVID-19.

Challenge

Certain areas of the hospital, that have had to be made available solely for the assessment and treatment of patients with suspected COVID -19, are currently positive pressure environments. In an effort to contain the virus, they will need to be converted to negative pressure environments.
It is also essential that the staff on these wards, as well as in other departments within the hospital that remain in operation, are able to carry out their work without disturbance at this increasingly busy time

Solution

The areas allocated by the hospital for the treatment of COVID-19 patients have required the following alterations to ensure effective control:
Replacement of positive pressure with negative pressure within the COVID-19 wards to prevent the virus from migrating outside of these areas. To do this, a vacuum is created by using an extraction system to remove contaminated air faster than it is replaced. As a result, air from outdoors rushes into the wards (via designated access points) to balance the air pressure in the room. Therefore, the virus is fully contained within the wards by the clean air that is being sucked in from outside.

The air change needed to increase to 12 air changes/hour. Generally, a solution should try and achieve 10 air-changes per hour. However, this may not be appropriate for very large or very small areas, as is the case here.

All handled air needs to be passed through HEPA H14 filter media to ensure highly effective filtration.

RVT decided that the combined use of the highly effective Ventex 300M and 450S centrifugal fans would create the best solution for this demanding project. The use of centrifugal fans was imperative, as axial fans would not have been able to provide enough pressure for the H14 filters and air changes required.

The fans were set up outside of the hospital, close to designated access points of individual COVID-19 wards, and each ward has it's own filtration and extraction system. The 300M fan is attached to the Dustex® Wandafilta, and the 450S fans are attached to RVT's brand new Dustex® Superfilters. These solutions are now connected to the building via lengths of single 5m 500mm diameter suction ducts, creating powerful extraction systems.