City University researchers have developed a ventilation system that costs only several thousand HK dollars but work as effectively as negative pressure wards costing tens of million dollars in hospitals.
They are also working on installing a similar mini system on top of toilet bowls, which is capable of sucking aerosols produced by a toilet flush and stop viruses from spreading.
The fast-track ventilation system is easy to install and can be used in high-risk places such as hospitals and washrooms, effectively reducing the risk of virus transmission, they said.
In a hospital setting, a transparent PVC hood with an anti-virus coating will be used to surround a bed. A central filtering system will be installed over it.
A patient's respiratory droplets are trapped in the filtering system, which can remove the viruses and transmit purified air back to the ward.
Experimental data shows that aerosols in an enclosed area can be thoroughly extracted by the system within two minutes. Its air change rate can be as high as 26 air changes per hour, higher than the rate of 12 ACH in a negative pressure ward.
In addition, setting up the system with pipes and a PVC hood is simple and takes only about five minutes per hospital bed. As inexpensive PVC is used, the cost for setting up the system is low.
The team is also collaborating with Gleneagles Hospital on a plan to install a tiny filtering system for toilet bowls.
As 5.5 million aerosol droplets on average are produced by each toilet flush, viruses may remain in aerosols in a washroom even if the toilet lid is down. If the toilet has been used by a person with Covid
-19, the next user will have a very high risk of viral exposure.
By using the new system, aerosols produced by a toilet flush can be sucked out within five seconds via an extraction port installed on the toilet lid.