How can ventilation systems prevent infection?

Over the course of the past couple of years, the coronavirus pandemic in the UK has led to an increase in awareness of how important good air quality is in preventing the spread of infections in an enclosed space.  During the winter months, when people spend more time indoors and in close proximity to each other, diseases such as Covid and flu can easily be transmitted to each other. 

The reason why respiratory illnesses spread so easily in enclosed spaces is that as people breathe, they spread virus particles in the air around them.  Without good airflow, the levels of virus in the air increase and this raises the risk that a person will come into contact with enough virus to become infected.

How does ventilation help against flu and covid

During the summer months, one of the main reasons why diseases such as flu and colds are less prevalent is that we spend more time outdoors rather than in close proximity indoors, and while indoors we are more likely to leave windows open.  When windows are open in a house, school, or office, the amount of air flowing through the rooms is much higher, so the concentration of virus particles remains relatively low.

During the winter, when it is colder outdoors, we keep our windows closed to retain warmth and avoid wasting energy.  Unfortunately, this means that we also remove the ability for germs to escape and for stale air to be replaced with fresher air as readily.

A good ventilation system that allows air to be drawn in from outside rather than just recirculating the existing air in the building will refresh the atmosphere indoors and help to keep the levels of infectious particles and viruses at levels that reduce the spread of diseases like flu and COVID.

How ventilation systems work

There are two main types of whole building ventilation systems which work in subtly different ways to maintain airflow.

Positive Input Ventilation (PIV) systems draw air in from outdoors through a filtration system, and disperse this into different rooms in the building.  This fresh air displaces the indoor air and pushes it gently out of the building.  PIV systems can be retro-fitted into an existing building and also help to reduce condensation levels from bathing and cooking which can ultimately cause damp.  The filtration systems also help to keep air free from particles including pollution and pollen, which helps to reduce allergies during the summer months.

Mechanical Extract Ventilation (MEV) works in the opposite way to PIV.  Rather than drawing air into the building, MEV systems, push air out of the building in a similar way to a traditional extractor fan.  This creates a slight negative pressure in the building which then causes fresh air to be drawn in from outdoors.  MEV systems can be fitted with heat exchangers to recover most of the warmth in the expelled air and use it to heat the air coming into the building.  This type of system is known as Mechanical Ventilation with Heat Recovery (MVHR).  MEV and MVHR systems are often fitted into a new build or as part of a major renovation of an existing building.

Find out more

During the COVID 19 pandemic, the importance of good ventilation has been recognised by governments and health care providers around the world as one of the key methods of reducing the transmission of infectious diseases indoors.  If you would like to learn more about how you can start to improve the air quality in your home, please contact us today to book a free survey.  Our local specialists can advise you about the best system for your property and answer your questions.