An effective ventilation system is an essential part of any home or business premises. Ventilation refers to any system that allows air to flow and move between the inside and outside of a property, providing fresh air for the occupants.
In the past, buildings relied on natural or uncontrolled ventilation. It could involve opening windows and doors, fixed air vents, and natural gaps in the structure. It is not always effective in a modern property, though, especially as energy-efficient homes and offices are built to increasingly airtight designs. Natural ventilation can either over ventilate or under ventilate a building and is uncontrollable.
Mechanical systems are often required to achieve the right rates of air exchange in a building. It can help safeguard the health of the occupants and prevent issues such as damp. For new-builds, it might also be a building regulations requirement, while some workplaces will have ventilation as part of their health and safety requirements.
There has been much recent attention on air quality and health, but this has largely focussed on outdoor air quality and pollution. While this is a pressing issue and one that we should all be concerned about, indoor pollution can be as bad or even worse. A study by the University of Sheffield, for example, found that the air in our homes can have pollutant levels up to three times worse than that in the outdoor environment, including by the sides of busy roads and in city centres.
Professor Vida Sharifi, who led the research, said: "We spend 90 per cent of our time indoors and work hard to make our homes warm, secure and comfortable, but we rarely think about the pollution we might be breathing in. Energy is just one source of indoor pollution, but it is a significant one. And as we make our homes more airtight to reduce heating costs, we are likely to be exposed to higher levels of indoor pollution, with potential impacts on our health."
There are plenty of pollutants released inside the home, including particulates released while cooking, burning candles and other combustibles, and volatile organic compounds (VOCs). These are potentially harmful gases, released from a variety of sources, including some paints and cleaning products, varnishes, floor surfaces, furniture, and new carpets.
Other contaminants, such as traffic fumes, can come in from outside, especially if you rely on natural ventilation with no filters. An effective ventilation system can help provide a constant flow of clean air, preventing the build-up of potentially dangerous pollutants.
Another potential danger of a badly-ventilated property is damp and the black mould it encourages. Condensation occurs when warm, moist air hits a cooler area or surface. Cooler air cannot hold as much water vapour so the vapour condenses back into liquid. It is a common problem in many UK homes. According to the last English Housing Survey (EHS), there were over a million homes in England alone afflicted by damp, with condensation being the most common cause.
Damp can damage your home and belongings, encouraging rot in wood, and cause plaster to crumble. It can also get into furnishings, such as curtains and carpets, furniture, and items left in cupboards and wardrobes. Just as significantly, damp can also pose a significant threat to health.
US health protection agency, the Centers for Disease Control (CDC) said: “In 2004 the Institute of Medicine (IOM) found there was sufficient evidence to link indoor exposure to mould with upper respiratory tract symptoms, cough, and wheeze in otherwise healthy people; with asthma symptoms in people with asthma; and with hypersensitivity pneumonitis in individuals susceptible to that immune-mediated condition. The IOM also found limited or suggestive evidence linking indoor mold exposure and respiratory illness in otherwise healthy children.”
The NHS adds: “If you have damp and mould you're more likely to have respiratory problems, respiratory infections, allergies or asthma. Damp and mould can also affect the immune system.” It says that some groups can be more prone to harmful effects from damp and mould, including children and babies, the elderly, and people with pre-existing conditions, such as eczema, asthma, and allergies.
There are several things you can do to help prevent condensation damp but installing an effective ventilation system is the single most effective. Extractor fans can be great for taking the moisture-laden air out of certain rooms, such as bathrooms and kitchens, while whole-house ventilation systems can help remove moisture from the whole property.
We are all aware of the dangers of carbon monoxide in our homes. It is known as the silent killer but, the lesser-known radon gas is linked to more deaths every year. Unlike carbon monoxide, which should always be taken seriously, it doesn’t kill immediately but according to the Radon Association, more than 2,000 people die every year from lung cancer developed as a direct result of exposure to radon.
Radon is a naturally occurring radioactive gas, released as the uranium present in rocks and soils throughout the UK decays. It is not usually present in concentrations high enough to be dangerous, but it can build up in some buildings. Some areas are more prone to higher rates of radon than others. Public Health England (PHE) has a range of interactive maps that show ‘Affected Areas’ in the UK. These only show the likelihood of high levels, and different properties can have different levels of radon even within the same area. Being in a low-risk area doesn’t mean you won’t have high levels of radon and vice versa.
Most radon build-ups start from the sub-floor level, so effective underfloor ventilation can help to prevent dangerous build-ups of the gas. PHE says that if a cellar is used as a living space and there is a risk of radon gas, you should install a special radon sump or a positive ventilation system.
Another reason to install effective ventilation in your home is that it creates a more pleasant living environment. As we’ve already seen, heavily polluted air and black mould can pose serious health risks, but stale air and bad odours can make your home less pleasant and affect your quality of life. A whole house ventilation system can ensure that you and your family always have clean, fresh, filtered air to breathe.
It’s not just the home that needs effective ventilation. Workspaces also need good ventilation, and in some cases, this may be a legal requirement.
The Health and Safety Executive (HSE) says: “All workplaces need an adequate supply of fresh air. This can be natural ventilation, from doors, windows etc. or controlled, where air is supplied and/or removed by a powered fan.”
Special systems or local exhaust ventilation (LEV) may be necessary if a workplace creates dust, mist, fumes, vapours, or gas and can only be specified by members of ILEVE. Office environments do not need this level of ventilation but many will benefit from some form of mechanical ventilation.
Sick Building Syndrome refers to situations where occupants of a building suffer from a range of symptoms with no obvious cause, which seem connected to time spent in that building. It is surprisingly common and according to one World Health Organisation report, could affect almost a third (30%) of new and remodelled buildings worldwide. No one is sure what causes Sick Building Syndrome and there are likely to be many contributory causes, but poor air quality and a lack of effective ventilation are generally considered to be a major cause.
If natural ventilation is not adequate for your property, you will need to consider mechanical ventilation systems. Extractor fans are useful for taking the dirty, stale, or damp air out of individual rooms but do not do a great deal for the rest of the building.
Whole-house ventilation can help provide a constant, gentle exchange of air throughout the property, helping to avoid condensation damp and the dangers associated with breathing in unclean air. There are even options for heat recovery units, which can transfer the heat from the outgoing air to the air drawn into the property, helping to improve your energy efficiency.
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