Ventilation systems – poor fresh air supply and stale air removal

Cause

Grilles (external or internal) are blocked/dirty

Repair

  • ask the supplier for maintenance or cleaning guidance. Some suppliers have this information available online
  • switch off the power, remove the grilles (they are usually held in place with clips or screws) and wash with warm soapy water. Allow to dry before reinstalling
  • while the grille is removed, gently clean inside the unit with a vacuum cleaner and a soft brush attachment
  • once the unit has been repaired or replaced, inspect and clean it once every six months or more often if required, following the manufacturers/supplier’s recommendations

 

Cause

Air filters are clogged/require cleaning

Repair

  • switch off the power, remove the grille covering (it is usually held in place with clips or screws) and clean the air filter(s) as recommended by the product manufacturer/supplier. In the case of old filters no longer performing adequately, replace with new
  • once the unit has been repaired or replaced, inspect and clean it once every six months or more often if required, following the manufacturers/supplier’s recommendations

 

Cause

Ducts are blocked

Repair

  • if the unit was installed by an electrician in recent years, call them back to identify the reason for the blockage
  • any electrician you call to do the work must hold an annual practising licence
  • some system manufacturers require installation and maintenance to be carried out by their own trained technicians
  • switch off the power, locate and remove blockages from the duct
  • identify if possible the reason for the blockage. If it is a result of missing or incorrectly installed or damaged filters, then install new filters
  • once the unit has been repaired or replaced, inspect and clean it once every six months or more often if required, following the manufacturers/supplier’s recommendations

Cause

Duct joints are not sealed resulting in air leakage through joints

Repair

  • if the unit was installed by an electrician in recent years, call them back to seal the joints
  • any electrician you call to do the work must hold an annual practising licence
  • some system manufacturers require installation and maintenance to be carried out by their own trained technicians
  • if you are sealing the joints yourself, turn off the power first
  • once the system has been repaired, inspect and clean it once every six months or more often if required, following the manufacturers/supplier’s recommendations

Cause

System is unbalanced due to differences in supply and exhaust ducting

Repair

  • if the unit was installed by an electrician in recent years, call them back to address the problem. This indicates a design problem – ventilation systems that both supply fresh air and expel stale air must be carefully designed so airflows are balanced
  • any electrician you call to do the work must hold an annual practising licence
  • some system manufacturers require installation and maintenance to be carried out by their own trained technicians
  • once the unit has been repaired or replaced, inspect and clean it once every six months or more often if required, following the manufacturers/supplier’s recommendations