Breathing fresh air into energy efficient homes

John Moss, Head of Social Housing Sales at EnviroVent, looks at how when energy efficient upgrades are carried out, it is even more important to get ventilation right.

“The World Health Organisation has warned that people living or working in damp or mouldy buildings are at an increased risk of respiratory infections and those with asthma will have their symptoms worsened. This is not an insignificant risk either, as around a third of people living in the UK report that they have mould in their homes.   

The condensation season starts now

At this time of year, with the nights closing in and a nip of frost in the air in the mornings, local authorities, private landlords and social housing providers brace themselves for what is usually the busiest time of year for complaints and remedial work. Most of these complaints arise from tenants whose homes are subject to condensation and mould growth.  As homes have been made increasingly airtight in recent years, a whole host of problems and issues have sprung up that are caused by a lack of ventilation. The main one is ‘damp’ in a home, the tell-tale signs being condensation on windows, outward facing walls and around floor level where there is lack of air circulation and relatively cool air exists. This excess moisture can lead to mould growth and the proliferation of dust mites, which has a detrimental effect on people with breathing-related issues.

Most at risk are families with young children, as are the elderly, who are more likely to suffer from respiratory or dermatological problems. This has been subject to lots of research, the latest being by Professor Hazim B. Awbi from the University of Reading, whose studies revealed that there could be an 80 per cent rise in those suffering with asthma symptoms by 2050.  But it’s not just in the future when this will cause a problem, asthma is a major issue now and cases have been increasing significantly in recent years.  

Indoor Air Quality (IAQ) is now being recognised as a major issue for our nation’s health, in the same way that outdoor air is too. Poor IAQ has been linked to allergy and asthma, lung cancer, chronic obstructive pulmonary disease, cardiovascular disease and even, more recently, to dementia. Poor IAQ is reported to have cost the UK over 204,000 healthy life years, with 45 per cent of those lost to cardiovascular diseases, 23 per cent to asthma and allergy and 15 per cent to lung cancer. According to the Royal College of Physicians, indoor air pollutants cause thousands of deaths per year and cost tens of millions of pounds to the NHS.

What can be done about it?

Indoor Air Quality is becoming recognised as such an important issue that an All Party Parliamentary Group on Healthy Homes and Buildings was set up in May 2016.  This has been looking into how to ensure that the Government has a public health focus that properly considers the indoor environment, as much as the external environment. The aim is to identify financial savings that can be made by raising building and environmental standards and/or retrofitting homes and buildings. It will also look at impacts, including lowering costs to the health service, improving the health of the population generally, reducing energy bills and the carbon footprint of buildings, enhancing wellbeing and creating greater life chances. The results of the APPG studies will be interesting and hopefully will influence Government policy in the future with regards indoor air quality.  


It is common knowledge that condensation is caused by a lack of a continuous flow of fresh air in and out of a dwelling to control the moisture content.  This means the relative humidity may rise to around 70-80 per cent, which then leads to condensation. The water droplets that form on colder surfaces can result in mould growth and, in some cases, damage to the building fabric itself.

Condensation is often more noticeable in kitchens and bathrooms where most moisture is generated, for instance from baths, showers and cooking. The situation is even worse when dwellings have internal bathrooms, with no windows, as often occurs in flats, which can be prone to serious condensation, especially if the extract fan is inadequate or not working.

Many social and private landlords and their tenants are looking for permanent solutions to the issue of poor ventilation. Weary of mould treatments that don’t work and with increasing numbers of people suffering with health-related issues caused by poor IAQ, these landlords are looking for a way to address this.

Lucky Thirteen

One social housing provider which has for many years recognised the importance of continuous ventilation to alleviate problems of condensation and mould is Thirteen, a social housing provider based in the Tees Valley. Thirteen has recent committed to a five year agreement to have our Positive Input Ventilation (PIV) systems and Filterless Infinity Fans fitted in its homes.

Thirteen carried out an in-depth ventilation review where it tested out a number of different ventilation systems and our products were found to be the most effective. The landlord and developer also recognised that contracting with EnviroVent meant longer warranties on ventilation products, technical support and surveys all as part of the package.

Our team will install PIV units or Infinity Fans on any properties that are having energy efficient upgrades, such as External Wall Insulation (EWI) schemes.

The PIV units for Thirteen will be fitted in the central hallway or in the loft space, providing whole house ventilation. These units take advantage of the benefits of solar gain from within the loft space, and help to redistribute heat around the home, reducing space heating costs.  Where Filterless Infinity Fans are fitted, residents will benefit from excellent performance, low maintenance and whisper quiet running.  These units are fitting individually in kitchens, bathrooms and other wet rooms.

Continuous ventilation means a reduction in harmful toxins

Another major issue when homes are made increasingly airtight is that it traps pollutants in the home, resulting in a much higher concentration of these, unless the building is adequately ventilated. There are a variety of natural and man-made airborne pollutants that exist in homes, such as Volatile Organic Compounds (VOCs), Radon and pollen. VOCs, which are chemicals emitted to the air from household furniture, cleaning products, aerosols and candles can be particularly harmful to the very young and to old people too, as well as anyone who is ill or infirm.

Given that many of the issues around poor IAQ are a result of increasing airtightness, there is at last becoming more recognition of the fact that ventilation systems need to be considered at the time of carrying out energy efficient upgrades.

For a relatively small investment, it means that any issues with condensation and mould growth can be solved, so there really is no reason why any household needs to suffer from the impact of poor indoor air quality.”

For more information on effective ventilation solutions, contact EnviroVent via the website or by calling 0345 27 27 810.