2013-09-10: Recently, much ado has been made in the technical press about a New Multi-Storey Office Block in Vienna which has achieved the German ‘Passivhaus’ (Passive House) Standard …
Is There A Problem ?? Yes !!
1. It takes approximately 3 Years of Building Occupation, by ‘real’ people, before the actual performance of a building can be properly monitored and reliably shown. The building is still ‘drying out’ for the first year. It takes at least one to two years of running the complex technologies and systems in today’s buildings … training people how to operate them efficiently and effectively … and fine-tuning and de-bugging as you go along … before everything begins to work together, as originally intended during the building design stage. Then, if all goes well … in the third year of occupation, the careful (i.e. accurate and reliable) monitoring of ‘real’ building performance, by means of portable measuring devices and devices installed within the construction, can commence.
So … what exactly has achieved the German ‘Passivhaus’ (Passive House) Standard … the design intent for the building, or the building’s ‘real’ performance ???
2. Much more fundamentally … achieving this Standard is a good starting point … but in a new building project … It Is Not Enough !
A. Energy Conservation and Efficiency Burden Sharing by Different Building Types
Separate strategies are required to greatly improve the energy performance of:
- existing buildings … onto which many energy efficiency measures can be successfully grafted, but it will be difficult work and will certainly not be cheap ;
- buildings of historical, architectural or cultural importance … the integrity of which must be protected ; and
- new buildings and facilities … which must therefore carry the major burden.
B. Paradigm for New Buildings – A ‘Positive Energy’ Return + Assured Building User Comfort
Primary Energy Consumption should be less than or equal to 15 kWh/m2/yr.
Renewable Energy and Heating Systems should contribute a reliable quantity of energy, per year, which covers the following:
i) the Building’s/Facility’s Primary Energy Consumption ;
ii) an Energy Efficiency Degradation Factor which takes account of the degradation in energy efficiency …
(a) normally expected during the life cycle of renewable energy and heating systems installed in the building. The rate of degradation will depend on the quality of maintenance and servicing ; and
(b) caused by wasteful patterns of building management and/or use ;
iii) the energy consumed by Private Transport associated with the building or facility ;
iv) an Energy Return to an Intelligent District, Local or Regional Grid exceeding, by a multiple of 3 (three), the total energy consumed by the Building/Facility (including its Energy Efficiency Degradation Factor) and any associated Private Transport.
Primary Energy includes the energy required to generate, transmit and distribute electricity, as well as energy directly consumed on site.
User Thermal Comfort = Air Temperature + Mean Radiant Temperature + Air Humidity + Air Velocity, i.e. draughts (ISO 7730).
And interestingly enough … on the Passivhaus WebSite (German language version) … www.passivhaus.de/passivhaus-informationen/vom-passivhaus-zum-plusenergiegebaeude.html … this is now the thinking there also !!
Should have been happening 10 years ago !