Houses are becoming far better insulated which means that they are also almost airtight. An airtight home means that there is little or no fresh air entering the building. Simply opening a window for fresh air is not sufficient and humans need fresh air to exist.

This is why  Mechanical Ventilation Heat Recovery (MVHR) systems or Heat Recovery Ventilation (HRV) systems are imperative for a healthy indoor environment.

These systems ensure that the air in your home is kept clean in an energy efficient way. The incoming air is purified by filters which is then passed to the heat exchanger. The stale air that is extracted also passes through the heat exchanger (without mixing with the clean air) and warms the clean air up. The filters that filter and purify the air of fine dust, bacteria and fungi need to be replaced on a regular basis* as an accumulation of these particles is not only bad for your health but affects the efficiency of the system. (*depending on personal health and the outside environment – filters that filter air in an urban environment will need to be changed more regularly than those in a more rural environment for example)

Balanced ventilation with heat recovery

Why do you need to replace your HRV filters regularly?

  • They reduce the amount of dirt (bacteria and fungi) within the indoor environment
  • They promote low energy consumption of the HRV system
  • They reduce the maintenance work  to system and thus enhances durability
  • They help prevent Asthma attacks (Asthma patients benefit from the HRV system)
  • They provide a consistent healthy home environment 

Reducing noise

If the filters become clogged with dirt and bacteria the heat recovery system runs at higher revolutions this then leads to increased noise levels. The system will also need to work harder to maintain efficiency thus using more energy and more energy means higher energy costs. 

Cleaning the air ducts

It is important to clean the air ducts but you can postpone this by replacing filters regularly and using f'air probiotics. You can do this yourself or ask your installer to do it for you. If however the air ducts do need replacing you can refer to your system user manual. For more information about fáir probiotics please click here.


A heat recovery ventilation system that is functioning properly ensures proper humidity levels in your indoor environment providing a comfortable environment in which to live. 

Cleaning HRV Filters

f'air HRV filters are made from the best quality materials and meet the highest European EN779 standards. HRV filters are not intended to be cleaned and reused. By washing or vacuuming the filters the structure of the material is affected and the filter loses its density. A filter with a changed density is not an effective filter, dirt i.e. bacteria and fungi and dust cannot be filtered properly resulting in an unhealthy indoor environment. Read here how often you should replace your HRV filters

Back to About MVHR / HRV