Lousy IAQ Analysis

Restaurants in Hong Kong must comply with the relevant provision of the FEHD licensing requirements. For Air-conditioned restaurants, typically the indoor air is largely recirculated with a small quantity of fresh air / outdoor air added into recirculating air steam.

By law, the minimum requirement is provided in clause 42 of the licensing requirements, only 17m3/hr/person (or 4.2 litres/sec/person) [1] of fresh air / outdoor is required, to put that into perspective that rate is lower than the normal 7-10 litres/sec/person rate.

Of course, the result is poor IAQ quality, because the air pollutants, including airborne covid19 [2] concentrations, are diluted extremely slowly.

“Poor ventilation may play a major role in transmission” RTHK reported the spread of covid19 investigation [3]. However, as explained above, it is no surprise, all Hong Kong restaurants have little fresh air/outdoor air, thus are poorly ventilated, and any bacteria/virus in the air is not diluted.

[1]https://www.fehd.gov.hk/english/howtoseries/forms/new/A_Guide_to_Restaurant.PDF#page=31 
[2] http://www.kelcroft.com.hk/20200404-news-covid19.htm
[3] https://news.rthk.hk/rthk/en/component/k2/1537915-20200715.htm

Building Drainage Systems and COVID19

In the good old days the topic was called Public Health, nowadays its called Plumbing and Drainage. It is essential for all buildings to have properly designed, installed and maintained sewerage systems to prevent infecting occupants, whether it is 2003 SARS, 2020 COVID19, or Influenza.

youtube is unreliable here is the link: https://www.youtube.com/watch?v=Uv38qdl4Z1M

Recently, when COVID19 infection was discovered spreading within Hong Mei House, Tsing Yi on 10 and 11 February 2020, the RTHK report stated that the HK Government instantly reported it was not a “U trap” problem [RTHK link] a reference to the SARS outbreak in 2003 where the disease spread through the drainage system in block E Amoy Gardens infecting occupants, and requiring evacuation of the block.

youtube is unreliable at the moment, here is the link https://www.youtube.com/watch?v=GTNvTuV_CM4

I predicted the cause would be the sewer vent pipe, vent pipes are part of the high rise drainage system designed to prevent loss of the water seal in U traps. Subsequently, my suspicion was confirmed, the SMCP newspaper confirmed that the vent piping inside the bathroom was damaged (see SCMP photo below). Therefore, droplets could contaminate the bathroom area.

CREDIT: SCMP Government Press Conference Handout — BROKEN VENT pipe

Still problems in 2020

The photo below taken 15 March 2020 shows damaged drainage system vent piping.

ABOVE: faulty drainage system spreads disease taken 15 March 2020

That drainage system is damaged, it is no longer an enclosed system, allowing odour, bacteria, virus to escape into the air.

We have always known that sewerage and drainage systems are important, providing a conduit for bacteria and viruses, yet the severe lessons from SARS in 2003 and now from COVID19, demonstrate lessons still have not been learned!

COVID19 and Buildings – Tsing Yi

UPDATE

14 March 2020 – Another similar incident is reported at Heng Tai House, Fu Heng Estate, Tai Po [link]


RTHK reports [link] some apartments in Hong Mei House, a residential tower block located in Tsing Yi, Hong Kong have been evacuated overnight after another person was diagnosed with the novel coronavirus (covid19) living in the same building, 10 stories directly below a person already diagnosed with the infection.

And fearing a repeat of the SARS in Amoy Gardens Block E, the HKSAR Government swiftly reported that the drainage U traps are in “good condition”.

Notwithstanding, the condition of the U trap, not every building (see photo below) has U trap fitted.

In addition, we must also consider faulty vent pipes (refer to our photo below). Vent pipes are connected in parallel to the main sewer system, well they should be, therefore any broken, damaged or disconnected piping provides an equally risky conduit for droplets and pathogens to spread into homes.

As shown in this video clip below, if the bathroom is negatively pressurised, pathogens can be dragged into the bathroom contaminating surfaces, risky infection of the occupants.

#coronavirus #hongkong #2019nCOV #airbourne #kelcroft #novelcoronavirus #SARS #drainage

Novel Coronavirus and SARS

A novel coronavirus emerged from Wuhan City, China in December 2019 (2019-nCOV) and it is apparent that it shares many similarities with the 2003 SARS outbreak, the virus is transported inside water droplets (aerosols) from coughing and sneezing in the air and its also shed in fecal matter which in turn is aerosolized risking contamination of surfaces.

History ignored is destained to be repeated, the same engineering issues remain today creating panic in the Hong Kong community.

Back in 2003, Kelcroft’s John Herbert was one of the few engineers that dared to visit buildings during the SARS outbreak, to highlight buildings requiring urgent improvements. You might not worry about a disconnected vent pipe, until you understand that’s a transmission path for the virus into your home.

Like SARS, and Legionella (which is bacteria) the novel coronavirus can be transported in the air, it’s said to be airborne pathogen, protected inside a water droplet, and depending on the air temperature and humidity, it is thought to be able to carry its virus package over long distances, outside and inside home.

And with favourable environmental conditions, the virus remains viable for up to 5 days on hard surfaces. ( link to useful Singaporean government list of household disinfection products).

If you are interested, here is a link to download our free SARS 2003 report: http://www.kelcroft.com.hk/download/kelcroft-sars-report-may-2003.pdf

#sars #coronavirus #hongkong #2019-nCOV #airbourne #kelcroft #2003