HOW DO YOU MAINTAIN AN MVHR SYSTEM?

Good maintenance matters when it comes to keeping your mechanical ventilation heat recovery system functioning well. Our expert explains exactly what's involved

- DAVID HILTON

Mechanical ventilation heat recovery (MVHR) systems have in recent years become more popular, especially in new-build homes. They ventilate the home at the right rate, recover heat from the stale extracted air and filter the incoming air to keep the home fresh and healthy.

While most MVHR setups are described as almost fit-and-forget systems, with claims that you only need to check the filter ‘every now and then’, this is only partially true. As with any mechanical technology there is always the chance of mechanical wear and tear, or even failure, and therefore periodic inspection and preventative maintenance is advised.

MVHR costs can be high, so you'll want to take care of your system properly to avoid any problems. It is also important to ensure it's serviced regularly by a qualified professional as well as the MVHR maintenance tasks you can perform yourself.

CLEANING THE FILTERS

As the manufacturers clearly state, the main component of an MVHR system requiring regular maintenance are the filters. That said, it’s not a difficult task or one that will take you hours. Most MVHR fan units will have a minimum of one set of filters. They are dust filters and could be either G3 or G4 filters. These are coarse particle filters with the G4 being slightly finer than a G3.

Other filters used for the supply air are F7 or F8 filters, which are very fine filters that can potentially filter fine airborne particulates such as pollen. Another filter that is often found in MVHR units is a charcoal (carbon) Nox filter.

This filter potentially filters out exhaust fumes or smoke, which is particularly useful near busy roads.