Passivhaus, also known as Passive House, is a fabric first approach and standard for energy efficiency in buildings focused on comfort, energy efficiency and wellbeing.
"Originating in Germany in the late 1980s, the goal of a Passivhaus is to create a comfortable and energy-efficient living or working environment while minimising energy consumption and reducing carbon emissions".
The Passivhaus standard is all about building the fabric of buildings to the highest standard and achieving a high level of thermal comfort while significantly reducing the need for space heating or cooling. Passivhaus or passive house can be achieved by following these 5 principles
By designing and achieving installed performance to these principles, Passivhaus buildings can achieve a significant reduction in energy consumption compared to conventional buildings. They typically reduce heating costs by 90% leading to lower utility bills and reduced environmental impact.
Why Is Passivhaus Increasingly Popular For Self Builds?
In the UK and many other countries, we are facing an epidemic of increasing energy consumption, energy prices, and cost of living. Although initially more expensive, Passivhaus does earn its stripes as a long-term investment.
The performance gap in a standard home is around 60% (the gap between energy produced and then lost through the home) whereas it is almost 0 in a Passivhaus home or building, and up to 90% of the heat is produced internally (by human occupants, appliances, the sun and more) is recovered and restored, much of this is done by the heavy insulation and airtightness of the buildings.
With this being said, ventilation is a key component for Passivhaus to maintain comfort and a healthy indoor environment and protect the home from condensation and mould. With Passivhaus design and certification you need mechanical ventilation to help circulate a fresh airflow throughout the building via a MVHR system (MVHR stands for mechanical ventilation with heat recovery) and the heat recovery aspect is where the heat is recovered and dispersed back into the home to help reduce energy bills.
MVHR is beneficial for any home, but as we move forward, anyone trying to improve their energy efficiency or achieve Passivhaus building standards will require MVHR.
If you are ready to start your Passivhaus MVHR project you can get your quote from The Air Shop in just 60 seconds.
What Role Does MVHR Play In Passivhaus?
Mechanical Ventilation with Heat Recovery (MVHR) plays a crucial role and is essential in Passivhaus buildings. The ventilation system is a key component designed to maintain a constant supply of fresh air while recovering and reusing the heat from the outgoing stale air.
Here's how MVHR functions and its significance within the Passivhaus concept:
Ventilation: Passivhaus buildings prioritise airtightness to minimize heat loss. While this is essential for energy efficiency, it also means that natural infiltration of fresh air is significantly reduced but the building and it’s occupants need to breathe.
Heat Recovery: The outgoing stale air from the building is passed through an MVHR unit which has a heat exchanger that transfers the heat from the outgoing air to the incoming fresh air. The heat recovery process significantly reduces the amount of energy required to heat the home.
Energy Efficiency: Combined with the super insulation, the MVHR recovers heat that would otherwise be lost, improving the energy efficiency.
Comfort and Indoor Air Quality: The MVHR system ensures a constant supply of fresh air while removing stale air, pollutants, and excess moisture from the building making indoor environments comfortable.
Temperature Regulation: MVHR units often include built-in heat exchangers that can regulate the temperature of the incoming air, allowing for additional control over the indoor climate. This feature helps prevent overheating during warmer months and ensures a balanced and comfortable temperature throughout the year.
Do I need A Passivhaus Accredited Heat Recovery System?
Passivhaus certification typically involves rigorous testing and verification of the building's energy performance, airtightness, and comfort levels. The certification process ensures that the building meets the stringent standards set by the Passivhaus Institute.
To achieve Passivhaus certification, it is required to use an accredited heat recovery system. The Passivhaus standard emphasizes the use of high-quality, energy-efficient components, including Mechanical Ventilation with Heat Recovery (MVHR) systems.
How Do I Know A MVHR System Is Passivhaus Accredited?
- Research Passivhaus Certification to understand more about the Passivhaus standard and its certification requirements.
- Check Passivhaus Institute Database: Visit the official website of the Passivhaus Institute and explore their database of certified products. The database provides information on various components, including MVHR systems, that have been certified and approved for Passivhaus projects.
- Verify Certification Labels: Look for specific certification labels or marks on the MVHR system's documentation, packaging, or the product itself. Passivhaus-accredited systems often display official certification marks or logos granted by the Passivhaus Institute.
What Makes A Unit Passivhaus Certified?
Different brands offer different benefits, here’s what Ubbink & Zehnder units offer.
Zehnder MVHR units offer:
- World class efficiency at 96%
- 100% full and filtered modulating summer bypass (excellent for helping to cool your house during the summer months)
- First unit recognised by the PHI for it’s ‘cold recovery’ efficiency
- No mechanical alteration needed for left or right variations – it’s all done through software
- A humidity boost continuously monitors the humidity levels within your home and looks for man-made spikes before boosting the unit, irrespective of distance or dilution
Ubbink MVHR units offer:
- A high thermal efficiency with low electrical energy consumption
- It’s innovative design is lightweight for easy installation
- Online commissioning tool offers a fully balanced system throughout the building
- Continuous airflow for a healthy indoor air quality and environment
Can I Use A Passivhaus Accredited Unit If I Am Not Building To Passivhaus Standard?
Yes, absolutely! If you're looking for a high specification, high quality system, offering the highest heat recovery efficiencies and additional functions such as pre-heaters or higher airflow rates Passivhaus certified units can be used.
Other Considerations for Passivhaus Projects
When building or aiming for Passivhaus or Passive House standards, there are a new extra considerations you'll want to know about:
Ducting - We always recommend semi-rigid ducting as it offers higher flexibility, durability durablility and is more suited to domestic spaces. When it comes to Passivhaus, we recommend Zehnder's line of pre-insulated ducting 'Comfopipe Plus'. It is suitable for all Passivhaus certified MVHR units and offers maximum recovery.
Additional components and accessories - In order to achieve maximum levels of comfort and higher airflow rates, accessories like seal rings can be used to make sure your MVHR system is 100% airtight.
Quality installation - The installation of your MVHR makes a huge difference to the efficiency, heat recovery (or loss!), how clean your ducting is, and noise levels. You should choose an installer who is expert and experienced, and if working towards Passivhaus, someone who is knowledgeable in this specific field.
#Passivhaus #Passivehouse #energyefficienthomes #Passivhaustrust #selfbuild #homerenovation
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