Passive House: Efficiency, Standards & MVHR Systems
Passive House Heat Recovery Systems
What is a Passive House?
Passive House is a construction concept, not a brand name. It stands for a building standard that is energy efficient, comfortable and affordable. It provides paramount thermal comfort with very low heating demand.
What’s passive about a passive house?
In short, the heating system. A Passive House doesn’t need to be actively heated because it uses passive heat gains to heat itself. Consequently, only a minimal amount of additional heating needs to be supplied. The concept is based on excellent thermal insulation and a highly efficient heat recovery system. The heat stays indoors and, therefore, doesn’t need to be provided by an active system.
When did Passive house start?
The Passive house institute (Passivhaus in German) was started in Germany in 1994 but the Passive House standard was conceived in 1988 when Professor Bo Adamson of Lund University, Sweden, and Dr. Wolfgang Feist of the Institute for Housing and the Environment, Germany, collaborated, The very first pilot project (the Kranichstein Passive House in Darmstadt, Germany in 1990) was Europe’s first inhabited multi-family home to achieve a recorded heating energy consumption of below 12kWh/(m2a) – just 10% that of the standard house at the time. This consumption level was confirmed via years of detailed monitoring.
Passivhaus Trust is an independent, not-for-profit organisation that provides leadership in the UK for the adoption of the Passive House standard and methodology. Its aim is to promote the principles of Passive House as a highly effective way of reducing energy use and carbon emissions from buildings in the UK, as well as providing high standards of comfort and building health.
Do all houses have to be Passive House Approved?
No, it is a construction concept and is not compulsory in the UK. In some areas of Europe local governments do sometimes specify new houses have to be Passive House Approved.
Is an approved passive house any better than a house built close to passive standards?
An Approved passive house is always going to be a much higher standard than a house built to passive standards as the level of airtightness, testing and products used are all tested and modelled to your home to supply a quiet and efficient home with minimal solar gain.
Is a passive house approved MVHR unit better than an un approved unit?
A Passive House heat recovery will sometimes appear on paper to be less efficient in energy consumption and thermal efficiency but would be guaranteed to supply a higher quality heat recovery system in real life situations. If preferred the use of a non-approved heat recovery unit is possible in a passive approved house but would include a penalty that would have to be offset from another item.
What is the difference in the units?
For a heat recovery unit to become a certified passive house approved unit it must pass a range of real-life tests and criteria set by the passive house institute that are completely different from that done by BRE (Sap Appendix Q). Qualifying units better mirror overall efficiency within a dwelling more accurately.
The criteria include:
- Counterflow heat exchangers (not rotary wheel due to air contamination)
- F7 or higher filtration
- Above 75% thermal efficiency
- Heat recovery unit is less than 25dB.
- Air tightness of unit
- Insulation value of the heat recovery unit
- Controllability
- Lifetime construction
What MVHR units do we offer?
MVHR is a fundamental part of a Passive House Design and BPC have many years' experience working projects that need effective ventilation without compromising energy strategies and offer an extensive Passive House Accredited Range of MVHR Systems.
BPC stock a large range of passive house approved units that include the Airflow Adroit and Xpelair units, as Passive house become more mainstream you will find that most quality manufactures will be supplying Passive house approved units.
Do I have to use a Passive house approved unit?
If you cannot install a passive house approved unit to a passive house the passive house academy will impose a 10% penalty to the MVHR system.
