As Housing Associations build homes to meet the increasing demand, air tightness of these new builds can cause issues if effective ventilation is not included. Ian Mitchell, Product Marketing Manager - New Build Residential at Vent-Axia, explains how indoor air quality (IAQ) plays a large part in inhabitants’ health and how the latest energy efficient ventilation and filtration systems can make a real difference to residents’ comfort.
Modern, air-tight homes can present issues for residents’ comfort. Whilst air-tightness is advantageous for conserving heat and reducing energy costs, without appropriate ventilation they are prone to the accumulation of air pollutants, resulting in poor IAQ. Optimising ventilation is therefore essential for a comfortable living environment and Mechanical Ventilation with Heat Recovery units (MVHR) are the ideal choice for new builds since they provide excellent IAQ while keeping fuel bills down.
The Chief Medical Officer’s 2017 Annual Report ‘Health Impacts of all Pollution’ identified vulnerable groups as being more affected by poor air quality and said “Action to reduce pollution is action to prevent ill health”.
By installing MVHR Housing Associations can provide a healthier environment for residents as MVHR reduces excessive moisture in the air, combating condensation and subsequent mould growth. This drastically improves IAQ and also offers the duel health benefits of reducing microscopic fungal growth and eliminating the conditions in which house dust mites thrive, both of which are linked to allergic reactions and asthma. The ‘fresh air’ benefits of MVHR cannot be underestimated.
Saving energy and costs
Recent advances in energy efficient MVHR technology, in particular those with high thermal efficiency and low specific fan power, mean that these systems can demonstrate a net cost saving over their lifetime. For example, Vent-Axia’s Sentinel Kinetic Advance delivers the lowest specific fan power available of 0.38 and can also achieve 93% heat recovery.
A unit ventilating a three bedroom house may consume 20 Watts, equating to an annual running cost of only £22.77 at 14.4p kW/hr, plus energy recovered may be ten or twenty times this figure.
Another benefit of MVHR systems is that they provide filtration of the outside air before it enters the building rather than bringing external pollution straight into the home. Enhanced filtration can be added with cutting edge filtration systems. For example, the Vent-Axia Pure Air is fitted to the MVHR supply airflow and incorporates two types of filtration: enhanced activated carbon which removes unpleasant odours and harmful gasses such as Nitrogren Dioxide; and particulate filters which remove tiny airborne contaminants such as pollen, bacteria and PM2.5 diesel particulates.
Modern homes are at risk of overheating in summer which affects resident comfort. MVHR helps maintain the target temperature of the internal environment and, if the overheat point is reached, more sophisticated MVHR units such as the Advance employ a summer-bypass to accelerate cooling by taking advantage of lower external air temperatures.
Quiet operation is also important for resident comfort. In her report, the Chief Medical Officer said “Noise stands second to poor air quality in terms of the burden of ill health caused by a single pollutant.” MVHR units can offer quiet operation as well as high efficiency. For example, the Advance achieves low sound levels of less than 20 dBA even on trickle settings of up to 35%. Correct installation also affects noise levels and Advance offers radical improvements to the commissioning process which helps ensures system performance. When electricians use a vane anemometer to measure airflow they can use Advance’s App to control airflows, making it unnecessary to repeatedly return to the unit to adjust fan speeds. This reduces installation time and helps ensure accurate commissioning, in turn ensuring efficient and quiet performance and optimised ventilation.
Although it has often been overshadowed by concerns around outdoor air pollution, the quality of the air inside the buildings in which we spend most of our lives must be a priority for Housing Associations. New technology, such as that offered by MVHR and filtration systems, provides an efficient and cost-effective way to ensure residents’ indoor environment remains healthy year-round.