A passivhaus home in almost all climates across the world will include a mechanical ventilation system with heat recovery (MVHR*). This kind of ventilation system is required for both energy efficiency and for comfort. However, to many people this is an intimidating and misunderstood aspect of passivhaus. As a result, there are various concerns and misconceptions about what a passivhaus ventilation system is and how you use it.

To address some of these issues I have enlisted the help of Zehnder, a global supplier of Passivhaus Certified ventilation systems. In this post, we explore the following aspects of a residential passivhaus ventilation system:

  1. How do I control the ventilation system?
  2. What day-to-day interaction do I need to have with the ventilation system?
  3. What is the boost function and when should I use it?
  4. When should I switch the ventilation system off?

Rupert Kazlauciunas, Senior Technical Advisor at Zehnder Group UK, very kindly provided answers to my questions

In a residential passivhaus, the ventilation system can be simple to use. It will save energy and money, while ensuring comfort and excellent indoor air quality.

029 Residential Passivhaus Ventilation System
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This is a Passivhaus Basics blog post that gives an overview of a specific aspect of the Passivhaus Standard.

In passivhaus design and construction, there are frequent references to the “building envelope” and the “thermal envelope.” Neither are exclusive to the Passivhaus Standard, but both are important aspects of the standard.

A building envelope is the physical separators between the conditioned and unconditioned environment of a building including the resistance to air, water, heat, light, and noise transfer. The three basic elements of a building envelope area weather barrier, air barrier, and thermal barrier. [Wikipedia]

In simple terms, this means that the building envelope is made up of the walls, floors, roofs (or ceilings), windows and doors that separate the inside from the outside. The passivhaus building envelope is also made up of these elements, but there are some key aspects that make the passivhaus building envelope distinct.

The passivhaus building envelope requires a high-performance thermal envelope, it must be continuous and it is key to the fabric first approach.

028 What is the Passivhaus Building Envelope
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