Omicron and MVHR

As of Christmas 2021 we have my son, his wife and our youngest grandson staying with us, the lad (12) came home from school with Covid last week first week of Feb 2022. All the rest of us did a test and all showed negative every day for a week.

We had rules, he spends a lot of time in his room or in my office with our mechanical ventilation with heat recovery system (MVHR) inlet blocked and the outlet in the anteroom opened up. I turned the MVHR up to full time 65% when we usually use a programme varying the flow between 35%, 45% or 60%(boost rarely used) and 15% overnight.

Our grandson ate separately and we minimised contact with him. He wears a mask if he comes in the lounge with us and that is limited to 15mins, he washes his hands a lot.

Three days into this regime none of us were positive, it is worrying though and I was certain that we would all get COVID. Upstairs we have three bedrooms all with MVHR inlets, landing and bathrooms have extract so bedrooms are under a slight positive pressure and any aerosols can’t float into other bedrooms, they are extracted from the landing and bathroom up there.

I estimate that we are on just over one and a half air changes per hour.

My son says that following the rules is all that you need to do, I like the ventilation system as it ensures that we breathe pre-warmed fresh air nearly all the time and that our grandson’s aerosols go to outside without us breathing them in.

Happy to be able to report that after ten days none of us caught it and that the lad is was clear after six days and went back to school.

My son was awarded an MBE in the 2021 Queen’s birthday honours list for his services to public health and research on Covid-19 in HK, where he is chair professor in the public health department and helped keep HK zero covid for over 18 months.