April 2016

Commercial Ventilation – Making an Informed Choice

Ensuring optimum air quality

The typical guideline for fresh air supply in commercial environments is around 30-36 m3/h per person. Therefore the extraction of airborne pollutants is an important function of ventilation systems. Many modern systems are designed to extract moist air that causes condensation and mould, and replace it with clean, fresh air that is circulated internally. At the same time, odours and airborne allergens such as dust, pollen and mould spores that can exacerbate hay fever and asthma are filtered out.

ErP compliance

The 2015 update to the Energy-related Products Directive (ErP) requires all fans and motors to comply with strict requirements to improve the efficiency of high energy-consuming building services. Many building managers and engineers automatically assume that they need to replace their entire ventilation system to meet the new guidelines, however, the logical and most cost-effective approach can often mean simply upgrading the fan.

Electronically commutated (EC) centrifugal fans consume up to 80% less energy than conventional AC motors, whilst offering significant noise reduction, variable speed control and remote monitoring options. Therefore, replacing the fan is typically the simplest method of ensuring that a ventilation system is Ecodesign and ErP compliant.

Effective operation and maintenance

A ventilation system that is straightforward to operate and maintain will help ensure that it remains effective. There are a range of Mechanical Ventilation with Heat Recovery (MVHR) systems on the market that not only run more efficiently than traditional ventilation units (thereby saving on energy and heating costs) but that also minimise maintenance requirements.

Smart units can connect to building management systems (BMS) and enable service technicians to access and control them remotely via smartphone or computer, reducing potential system downtime if any faults are detected.

They can also prevent energy from being wasted via constant manual adjustments made by building occupants – a common issue in commercial buildings. Users can remotely monitor indoor temperature, CO2 and humidity levels, and accurately adjust the system if necessary, in order to maintain optimum indoor air quality and internal comfort levels throughout the year.

Alternatively, a de-centralised mechanical extract ventilation (dMEV) system can be a useful addition in highly insulated buildings. Where traditional ventilation systems work on an intermittent basis, dMEV units are in constant operation and come equipped with an ‘on-demand’ boost speed that kicks in with no human intervention required. Intelligent controls can minimise the length of the boost speed, ensuring that running costs for the fan are kept to a minimum.

Check the regulations

Building Regulations Approved Document F sets out the requirements for extract ventilation airflow rates in buildings. The guidance also highlights the importance of correct installation, commissioning and regular maintenance of ventilation systems so that optimum performance continues to be achieved once the system has been installed.

Finally, to really make an informed decision – be sure to look at specification sheets and product catalogues on manufacturers’ websites. Check fan performance curves/statistics to help identify which fan will offer optimum benefits for each individual project. This willl ensure an effective system, is in place that is easy to maintain, and users benefit from improved indoor air quality.