16 June 2020

In recent years, the issue of effective ventilation in the built environment has been brought to light. With people spending an estimated 90 per cent of their time indoors, coupled with the drive to insulate homes and improve thermal efficiency, indoor air quality has been catapulted up the agenda, particularly when it comes to health.

Good ventilation is essential for reducing the occurrence of damp and mould, which is renowned for its impact on wellbeing. In social housing and rental properties there are further compliance and maintenance issues that can compound damp issues. The difficulty in accessing properties for maintenance by landlords and improper use of installed ventilation units by residents are influential examples.

And it’s not just older properties that have damp issues. Newer, airtight homes with poor fan installation also fall foul.

So, what exactly is the impact of poor ventilation and what can be done to mitigate risk?

Poor ventilation leads to damp and ill-health

Last year the Local Authority Building & Maintenance Magazine (LABM) reported on a survey carried out by independent assessor CIT, who specialise in tackling problems associated with property insulation. The survey uncovered that damp, condensation and mould are still very real issues for thousands of social housing tenants across the country. More than 12 per cent of the total housing stock of respondents had been subject to a complaint relating to damp, condensation and/or mould.

Poor ventilation is one of the most common causes of damp, and associated poor indoor air quality is leading to the exacerbation of health problems, such as asthma and dermatological conditions. Last year NICE published guidelines on ways to reduce exposure to indoor air pollution, which included advice on ensuring rooms are well ventilated.

Professor Gill Leng, deputy chief executive and director of health and social care at NICE said: “Evidence shows that homes with poor air quality are linked to an increase in risk of health problems.”

There is a huge cost to society if the issue of ventilation in social housing isn’t adequately resolved. It not only impacts on the economy in terms of absence from work due to ill-health, but also on the cost to government for healthcare, as well as actual deterioration to the housing stock. The cost of fixing damp problems in poor housing is huge.

The problems with ventilation in social housing

Unfortunately, social housing is more likely to suffer damp issues due to poor ventilation, as well as overcrowding, inadequate heating and a lack of maintenance by landlords, which are all, ironically, also concomitants to the development of damp. And it’s not just older properties that are cursed with damp problems.

In a report by Inside Housing, lawyer Giles Peaker explains “Quite a lot of new builds might have problems because they have been built to be energy efficient, but they are inadequately ventilated and therefore prone to mould.”

Many people now spend a lot of time indoors and are completely unware of the pollutants created through cooking and cleaning. This is a big concern, particularly in cities where windows are opened less due to worries about outdoor pollution.

A lack of knowledge around adequate ventilation can also mean tenants turn noisy extractor fans off, unintentionally exacerbating damp and mould problems. Landlords equally face a difficult time trying to access properties to ensure regular maintenance of extractor fans or ventilation systems are carried out.

Why dMEV offers a radical solution

Firstly, what is dMEV? The abbreviation, dMEV, stands for Decentralised Mechanical Extract Ventilation. It is a form of low energy continuous ventilation designed to replace conventional bathroom fans and draw moisture laden air out of wet rooms.

dMEV offers a superior solution for homes already fitted with poor quality extractor fans, which is often the case in older social housing units. dMEV can easily be retrofitted in place of existing intermittent kitchen and bathroom fans.

This type of ventilation (dMEV) runs continuously with low noise levels so it takes out of the equation the necessity for tenants to turn fans on and off. Although it is still physically possible for tenants to turn dMEV fans off, Zehnder Greenwood’s Unity CV3 data logging enables landlords to monitor and detect when units have been disabled.

dMEV offers localised control of humidity. Units with a SMART humidity sensor ensure the units only run at the right time, avoiding noise nuisance and ensuring energy efficiency during the night. Unity CV3 units also offer a ‘do not disturb’ feature to prevent the unit boosting at night.

It is increasingly recognised that indoor air quality requires continuous attention. Even when bathrooms and kitchens aren’t in use, condensation can form from high occupancy, wet clothing and fluctuations in temperature.

In addition, indoor air quality is compromised by hazardous substances emitted from buildings, construction materials and indoor furnishings or from human activities, such as smoking or combustion of fuels for cooking and heating.

dMEV is a sound investment enabling prevention of damp and condensation and ultimately negating the high service costs associated with damp-ridden homes, not to mention the social cost of damp-related ill-health. Poor indoor air quality, damp and mould are serious issues for social housing providers. dMEV not only addresses issues of damp, it has also been shown to reduce other internal harmful pollutants, such as formaldehyde and carbon monoxide (CO).

A recent government study (2019) evaluated whether ventilation provisions recommended in the latest (2010) edition of Approved Document F (ADF) of the Building Regulations provide satisfactory indoor air quality in new homes.

In the study, all homes with dMEV were found to have formaldehyde levels lower than World Health Organisation (WHO) guidelines for this pollutant. CO and NO2 (nitrogen dioxide) levels also did not exceed ADF guidance limits for these particular pollutants in homes with dMEV.

High quality dMEV products are unobtrusive, economical to operate, and easy to install. They reduce human intervention whilst ensuring the fan operates at its optimum level. They also achieve low noise levels. Damp problems and excessive indoor pollutants in social housing can be resolved. For a radical and innovative solution, it starts with replacing outdated, ineffective fans with dMEV.