air conditioning & ventilation Look after your ventilation


Well-maintained ventilation systems can reduce overall building repair and maintenance costs for social housing landlords, while improving occupants’ health and well-being. Michelle Sharp of Greenwood Airvac explains how.


W


e would all agree that a well ventilated home is essential for a comfortable, healthy living environment and happy and healthy occupants. However, it is also the case that the number of


occupants in the dwelling and their behaviour will affect the performance of a ventilation system. The on-going maintenance of that system can also have an effect. For example, the average family home can create up to 17 pints of moisture per week from everyday activities such as cooking, bathing and showering. A badly or incorrectly maintained system will not deliver fresh air or


expel stale air, which can potentially lead to condensation and mould issues and can cause a build-up of indoor pollutants such as dust, pollen, household chemicals and biological materials - all potentially damaging to health. Increased noise levels is another consequence, as pressure builds up due to dust and debris, the fan or system have to work harder , ultimately affecting performance. It’s a worrying issue and one that looks to become worse, if not


addressed. Recent research for BEAMA, the UK’s electro-technical industry body, found that more than one in three UK homes are at an elevated or severe risk of having polluted indoor air, and that this can be up to 50 times more polluted than the air outdoors. BEAMA also found that 58 per cent of people have suffered mould or condensations in their home and 81 per cent of people are at risk from suffering a respiratory or dermatological condition by 2050 because of poor air quality inside their home. Social landlords have a duty of care to their occupants, so it is essential


that both the choice of ventilation systems for their properties and their maintenance are given high priority over the long term.


Mechanical ventilation systems


Building Regulations and the drive towards efficient homes means that simply opening windows or doors is no longer enough. Ventilation in airtight homes needs to be balanced and controlled. Often, because of the weather, security issues, noise and outdoor air pollution, opening a window is not always possible anyway. Mechanical ventilation systems deliver filtered, clean air into a home and can precisely control airflow. But, if financial pressures lead to skimping on system maintenance, noise levels could rise, performance will decline, and benefits will be lost. A number of different types of mechanical ventilation systems are


frequently installed across the social housing sector. These vary in their purpose, capabilities and maintenance requirements, but ultimately all will help reduce building maintenance by promptly extracting air laden with condensation and preventing the conditions that can create mould. The simplest type of mechanical ventilation for energy-efficient homes


comes from continuous extract fans. These are a one product concept – one fan, any room, all installations - designed to run continuously at a very low speed, with boost operation typically activated by the light switch. The popular Greenwood CV2 fan, for System 3 compliance, costs as little as half a penny per day to run. Intermittent extract fans for bathrooms, WCs and kitchens provide traditional on-off ventilation and are controlled by the occupant or


through automatic sensing. They are easily specified for all types of apartments and houses but are not necessarily the best option in buildings with low airtightness levels, where continuous ventilation is preferable. This is especially prevalent in new builds, because high levels of trickle ventilation are required within the window profiles. For whole-house ventilation, there’s mechanical extract ventilation


(MEV), sometimes also known as central extract ventilation. The central system is often mounted in a loft or cupboard and connected by ductwork to multiple wet rooms throughout the building. The most sophisticated of all systems and the most beneficial


economically, is mechanical ventilation and heat recovery (MVHR). By re- using up to 96 per cent of a building’s heat loss, it helps to cut energy use and heating bills for end users, while ensuring balanced fresh air and comfort throughout the year.


Maintenance matters


Performance losses are suffered in fans when dust and dirt is allowed to build up in them. Some fans will maintain a constant airflow rate when this happens, but in doing so they get noisier. Other systems simply fail to provide the desired airflow or end up not doing much extracting at all. This means regular maintenance is vital – but it is also easy. All that’s


required to maintain fan performance in most systems is to remove deposits of grease and dust from the fan and grilles, and if possible, when isolated from the mains, inside the fan and on the impellor. It is crucial,


www.housingmmonline.co.uk | HMM July 2016 | 31


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42  |  Page 43  |  Page 44  |  Page 45  |  Page 46  |  Page 47  |  Page 48  |  Page 49  |  Page 50  |  Page 51  |  Page 52