Passivhaus ventilation commissioning best practice

Posted by on Jun 20, 2012 in news | Comments Off on Passivhaus ventilation commissioning best practice

Sally Godber and Rob Mcleod have put together a list of requirements for commissioning ventilation systems installed in Passivhaus buildings. As always we really like feedback and suggestions – so get in touch at!

Below are some additional requirements for commissioning of ventilation systems; this is over and above (or in some cases just highlighting) the requirements of the 2010 Building Regulations.


  1. Balanced supply and extract (<<10%) at a typical flowrate for each ventilation system.  Preference is for this to be undertaken on the fresh air & exhaust ducts rather than supply & extract.  Identify how & where measurements were taken from on a layout drawing or schematic
  2. Demonstrate rough balancing at highest & lowest used flowrates, record this information on Ventilation Commissioning sheet.
  3. Specific fan power (to include both fans) preferably at all the settings above.  For domestic units installing a plug and socket will allow quick access to the power, usually alongside the fused spur.
  4. Provide specific fan power at the typical flowrate for each ventilation system, to include both fans
  5. Confirm control settings incl. timeclock
  6. If possible, confirm the temperatures on the extract, exhaust & fresh air intake for typical flowrates (non-critical)
  7. Confirm condensate drain is working correctly and cannot dry out (if this happens air can bypass the heat exchanger) Confirm unit is installed level and that condensate drain is flowing correctly to trap
  8. Confirm unit has not been running during construction & is free from dust – photos to demonstrate heat exchanger is clean if possible
  9. Confirm clean filters have been installed correctly and of the specified grade F7 fresh air, G4 extract
  10. Provide pictures of name plate to demonstrate exact units provided (otherwise written declaration ok)
  11. Identify frost protection temperature settings & method of achieving frost protection.
  12. Confirm breakout low frequency sound from services room does not exceed 35 dB(A)


  1. Evidence to confirm flowrates to each usable space are achieved
  2. Noise levels within the usable spaces during typical flowrate <25dB(A)
  3. Confirm noise levels from wall mounted high velocity jets are acceptable and not whistling
  4. If there are any interconnected systems (such as WC bypass) need to demonstrate there is no unwanted leakage between the two, and confirm the controls settings
  5. Evidence (eg pictures) to confirm insulation depth and continuity on cold ducts & vapour tight.  Confirmation of actual lengths & sizes of ductwork used for ‘cold’ ductwork.
  6. Evidence of natural ventilation commissioning if motorised
  7. Evidence (eg pictures) to confirm complete ductwork is free from dust
  8. Photographs of typical terminals (and terminal connections) for supply & extract, otherwise confirm all as specified
  9. Photographic evidence of external inlet and exhaust (grills positioning, height and location)