The quality of the air we breathe can have a massive impact both on our comfort and our health. With most of us now spending the vast majority of our lives indoors, adequately controlling our air quality is more important than ever.
Many modern buildings are particularly susceptible to issues with air quality as they are designed to have a high level of air tightness. This is good for making buildings more energy efficient, as it reduces the amount of heat lost to the outside, thus reducing the amount of heating a building needs. However, it is also important to be able to bring in fresh air or condition the air that you have to maintain its quality. Otherwise the users of your building can quickly end up breathing very stale air with high levels of potentially harmful compounds.
Indoor air quality is controlled by Part F of the Building Regulations (2010). The following are some of the key factors affecting air quality that need to be considered when planning your building’s air conditioning.
Nitrogen Dioxide (NO₂)
Nitrogen dioxide is toxic if inhaled and even relatively low levels of exposure over long periods can lead to lung damage and an increased risk of breathing problems. Although NO₂ has a sharp, acrid smell it can have an anaesthetic effect on the nose making it easy to miss.
The average level of NO₂ people are exposed to should not exceed 288 micrograms per cubic metre (µg/m³) or 150 parts per billion (ppb) where the exposure is for an hour or less. Over longer periods the level should be less than 40µg/m³ (20ppb).
Carbon Monoxide (CO)
Carbon monoxide is odourless, colourless and tasteless making it almost impossible to detect without some form of detector. When inhaled, CO bonds with haemoglobin in our blood, preventing oxygen from being carried around our bodies. High enough concentrations can lead to seizures, coma and even death.
CO levels should not exceed 100 milligrams per cubic metre (mg/m³) or 90 parts per million (ppm) for periods of 15 minutes or less. For periods of up to 30 minutes, the safe level is no more than 60mg/m³ (50ppm). For periods up to an hour it is 30mg/m³ (25ppm) and 10mg/m³ (10ppm) for periods up to 8 hours.
Volatile Organic Compounds (VOCs)
The term ‘volatile organic compounds’ covers a wide range of chemicals which will take the form of vapour at normal room temperature. This includes both natural and man-made compounds and their diversity means they can have a wide range of symptoms. Common issues associated with VOCs include respiratory difficulties, allergic and immune responses, eye, nose and throat irritation, headaches, nausea and more.
The generally accepted safe level of VOCs in no more than an average of 300µg/m³ for periods of up to 8 hours.
Particulate matter
A high level of particulate matter in the air can be a particular issue in industrial buildings such as factories. High levels of dust and other particles can cause respiratory problems as well as irritation to the eyes, nose and throat. Adequate air filtration will allow you to remove these particles from the air and prevent a dangerous build-up.
Bio-effluents
Although not a health risk, bio-effluents a.k.a. body odour can make a big difference to the comfort of the people using your building. As a general rule, an air flow rate of 3.5 litres per second per person will be sufficient to remove body odour from the air.
TEK offer both commercial and industrial air conditioning to businesses through the UK. We also specialise in clean rooms and close control rooms for a range of industries. We provide everything from installation to servicing and repair, so to find out more, call us today on 0117 9523355 or fill out our contact form for a quick response.
