Killer arguments and opportunities for energy-efficient construction and the passive house

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Killer arguments and opportunities for energy-efficient construction and the passive house (2011) is a publication of the ENERBUILD project which was released in March 2011.

Contents of the publication:

  1. Ventilation of passive houses
  2. Heating and Cooling in passive houses
  3. Economic aspects
  4. Architecture and aesthetics of passive houses
  5. Sad/ unattractive name of passive houses
  6. Daylighting

The report analyze some presumed problems of passive house concept finding killer arguments (in other word final arguments, facts, solutions proving the actual possibility to realize effective building) and/or opportunities (for enterprises and research centre) will be provided for each problem considered.

Summary of the publication

The report analyze some presumed problems of passive house concept finding killer arguments (in other word final arguments, facts, solutions proving the actual possibility to realize effective building) and/or opportunities (for enterprises and research centre) will be provided for each problem considered.

The above problems were faced considering both technical-scientific literature and case studies, in order to deepen both theoretical and practical aspects. The opportunities (of business for SME) are mainly based on promising technologies and questions still open.

The following issues were treated: Ventilation, Heating and Cooling, Economic aspects, Architecture and aesthetics, Daylighting and the Sad/ unattractive name of the term "passive house".

High performance buildings are airtight buildings, not only for purely performance reasons but also in order to satisfy other building physics requirements: air infiltration inside structures must be avoided to prevent condensation. The (questionable) trend toward smaller housings (and, hence more concentrated vapor releases) together with air-tightness is making ventilation a critical issue. Ventilation issue can be handled through a careful design that uses an integrated approach. The design process must continue through a good commissioning and an accurate maintenance (both ordinary and extraordinary). Many opportunities still remains for SMEs that would like to optimize the present systems, also dealing with control and overall house managing.

Passive Houses are buildings which assure a comfortable indoor climate in summer and in winter without needing a conventional heat distribution system. To permit this, it is essential that the building‘s heating load does not exceed 10 W/m2. The small space heat requirement can be met by heating the supply air in the ventilation system. The standard has been named „Passive House” because the ‘passive’ use of incidental heat gains – delivered externally by solar irradiation through the windows and provided internally by the heat emissions of appliances and occupants – is essentially enough to keep the building at comfortable indoor temperatures throughout the heating period. Finally, to keep the desired indoor comfort conditions, when a good architecture was developed it is enough a good control of the heating (and/or cooling) system through appropriate measurements giving the needed input to be elaborate to launch actions that allow to adjust the systems setting to face internal and external loads.

Is it more attractive to buy the apartment in energy performance A or B? Considering that the lifetime of a building is equal to 50 years and reasonable payback time for this type of investment is 25 years, the choice of a real estate in ClimateHouse standard A rather than Climate House standard B is profitable.

In discussions about Passive Houses, often an image of a high-tech house, with no heating and very little freedom to design, comes into mind. Since a Passive House is meant to achieve certain goals by following certain rules, this seems to also become the main direction for the design, its architecture and aesthetics. The aesthetics of a passive house depends a lot from the technological solutions used to save energy, the needed input to be elaborate to launch actions that allow to adjust the systems setting to face internal and external loads.

Although currently, energy saving in the building sector is the most diffuse sustainability issue, this subject is not well known and accompanied by a skeptical approach. Often the interest and sensibility for these arguments is rejected due to the economic aspects, where an investment appears too high and payback period too long. The carried out analysis process the measure of the economic life of this investment in terms of its payback period is 11 years. It means that the capital return per year from the start of the project until the 11 years of accumulated cash flow is equal to the cost of the investment. After that in 19 years it will be possible to have a profit equal to an initial capital.

Is it more attractive to buy the apartment in energy performance A or B? Considering that the lifetime of a building is equal to 50 years and reasonable payback time for this type of investment is 25 years, the choice of a real estate in ClimateHouse standard A rather than Climate House standard B is profitable.

As Passive Houses often rely on passive solar gains through their windows to reduce the heating demand, in general, they should be equipped with accordant glazing that also provides good daylighting. If the window surfaces are large, they can collect solar gains well, but the same instance could also result in seasonal overheating. Therefore, a thoughtfully designed shading system in connection with precise application of matching glazing qualities could provide adequate heat protection, while keeping energy inside. Designers can use architectural (building shape, windows size, interior wall, etc.) and building (plaster painting) choices to better transport the light inside the building. Right balance among window surfaces, reveal finishing, Ug, g-value and Tv allow to achieve good illumination level while keeping very high insulation level. SMEs can find business opportunities developing cost-effective solar tube: collector, funnel, emission point that reduce space need on the roof and for light distribution.

References

Killer arguments and opportunities for energy-efficient construction and the passive house (2011)