The potential for energy saving in existing solid wall dwellings through mechanical ventilation and heat recovery

Phillip Frank Gower Banfill, Sophie Ann Simpson, Mark Gillott, Jennifer White

    Research output: Chapter in Book/Report/Conference proceedingConference contribution

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    Mechanical ventilation with heat recovery (MVHR) is increasingly
    being promoted in the UK as a means of reducing the CO2
    emissions from dwellings and installers report growing activity
    in the retrofit market. The behaviour of a whole-house MVHR
    system installed in an experimental house, purpose built to
    typical 1930s standards, has been simulated, at a series of air
    permeability values corresponding to those achieved in the retrofit
    upgrading process. There is a critical value below which
    the air permeability, as measured in a 50 Pa pressurisation test,
    must fall before MVHR makes an overall energy saving. In the
    house considered this is 3–5 m3/m2.h (4–6.5 ach-1), although
    more significant savings of 9-12 % are achieved when the
    air tightness is improved to Passivhaus standards of 0.63 m3/
    m2.h (0.6 ach-1). When the CO2 emissions are considered, the
    air permeability needs to approach Passivhaus standards to
    ensure an overall reduction, because the electricity needed to
    run the MVHR system has a CO2 intensity almost three times
    that of the gas used to heat the house. Airtightness is a critical
    factor in achieving energy and CO2 reductions and it is easy for
    designers to over-estimate the potential savings.
    Original languageEnglish
    Title of host publicationEnergy efficiency first: foundations of a low-carbon society
    Subtitle of host publicationProceedings of ECEEE 2011 summer study on energy efficiency
    Number of pages12
    Publication statusPublished - 2011
    Eventeceee 2011 Summer Study on energy efficiency - Belambra, Presqu'île de Giens, France
    Duration: 6 Jun 201111 Jun 2011


    Conferenceeceee 2011 Summer Study on energy efficiency
    CityBelambra, Presqu'île de Giens


    • Ventilation
    • Retrofit
    • heat recovery
    • Simulation
    • dwellings
    • CO2 savings


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