Mechanical ventilation with heat recovery (MVHR) is very much like a controlled heating system, recovering heat from the home, office or commercial building. There are many parts to the system which combine to supply and extract air to make buildings more comfortable with a constant temperature, and to re-circulate the air to prevent it becoming stale. These systems are also energy efficient as they re-use heat inside the building, so it is no surprise that they are becoming increasingly popular. But there are several common errors in the installation of such systems that result in the property owner not seeing the optimum benefits.
Is the property suitable? – A MVHR system will only provide the best performance results in an airtight building, ie. one that is well-insulated and without draughts and the constant opening and closing of doors or entrances, such as a warehouse.
Design the ductwork layout correctly – Having a layout design with several bends can increase airflow resistance dramatically. Designing the ductwork as direct as possible should maintain efficient and more precise airflow.
Get the system capability right – In this case, size does matter. Many people try to save money by installing a system without the capability to properly ventilate their building. A unit that is undersized will be overworked, which will create unnecessary noise and will utilise more energy and therefore cost. Industry good practice suggests the fan power should be running at around 60% capability to make the system cost-effective.
Prevent condensation forming – This can happen where ductwork runs into roof voids or other areas of the property that are outside the normal heating system. These areas tend not to be insulated and hence, if your ductwork is not insulated condensation will form. This can cause problems in the system, and so you also need to provide an outlet drain.
Location, location, location – The heat recovery unit will create some noise, that is unavoidable, but common sense suggests some locations are better than others. So locate them in utility rooms, store cupboards, basements or plant rooms, not communal rooms or offices. You also need to consider access for maintenance when seeking a suitable location.
Prevent cross-contamination – Locating intake and exhaust terminals close together can result in potential pollution of the air, so follow a rule of thumb to allow at least 1m distance between the ductwork terminals.
Air valves – The positioning of air vales should be in accordance with their function, ie. whether they are supplying air or extracting it, so think about tall obstacles or where there are open doors or draughts.
Get the commissioning right – Many people think that once the system is installed everything is OK, and they can simply run the system at factory settings. However, this can result in the system overworking and you not seeing the benefits. Proper commissioning ensures the MVHR unit meets your specific airflow requirements in the most efficient way, this should reduce noise and also your energy bills. A qualified commissioning engineer will have a checklist to set-up, measure and balance the airflow and leave you with the correct settings and instructions with which to operate it to your optimum requirements.
At Robinsons we have a team of qualified and professional engineers who can advise on the right MVHR system for your premises, we can design, install and commission the system for you and we can then also set up a routine maintenance system to ensure you get the most benefits for years to come. Please click here to contact us.