Residential Passivhaus Ventilation – Q&A

As you know, one my favourite Passivhaus resources is Elrond Burrell’s website. Elrond’s blog is informative and easy to read.

I wanted to share a recent post of his with you, where Elrond discusses a number of common questions about Ventilation in residential Passivhaus buildings.

A passivhaus home in almost all climates across the world will include a mechanical ventilation system with heat recovery – such systems are required for both energy efficiency and for comfort. However, this is an often poorly understood aspect of passivhaus.

In this post,  Elrond and Zehnder, a global supplier of Passivhaus Certified ventilation systems, explore various aspects of a residential passivhaus ventilation system, including:

  • How do I control the ventilation system?
  • What day-to-day interaction do I need to have with the ventilation system?
  • What is the boost function and when should I use it?
  • When should I switch the ventilation system off?
  • and more…

It is an informative and interesting read – and can be read here:


Passivhaus Design & Build Podcast

This is a great podcast with two of the top proponents for Passivhaus in the UK (Elrond Burrell and Chris Herring) talking about aspects of design & how the standard of construction really matters with some really interesting comments about thermal mass.

It is well worth a listen.

You can find it here:



Zehnder Heat Recovery and Ducting Systems – HRV – ERV

As we push up the level of thermal comfort in our homes we work to eliminate unwanted heat flows and reduce draughts to save energy. Until now this has meant simply retaining the conditioned air inside our homes for as long as possible.

The problem with this is that the carbon dioxide we breath out builds up and makes us feel tired and the toxic gasses emitted by the furniture and finishes in our homes builds up to dangerous levels. The moisture content increases causing condensation and mould growth which can be dire for asthmatics and damaging to the building fabric.

Fresh air ventilation is the solution to this but how to achieve this without wasting the energy we’ve already used is the problem. A balanced heat recovery ventilation unit is the perfect answer to this problem and associated with good insulation and airtightness virtually eliminates the need for heating & cooling systems.

This video from Zehnder shows how the concept works.