"gugler! build & print triple zero" - subproject 4: energy concept Gugler
This project is a sub project of the flagship project "gugler! build & print triple zero"
The project "gugler" comprises research, applied experimental development, integrated planning of building services, erection of the building, monitoring and optimisation, and dissemination. The subproject 4 "Energy Concept Leuchtturm Gugler" aims at working out a general energy concept for the refurbishment of an existing, and an additional new building for the printery Gugler. The concept starts with an optimisation of the buildings' structure and shell, continues with efficient building services including use of locally available renewable energy sources. The overall aim is to achieve a "plus energy" standard for the building.
Contents and goals
Plus energy means in this context that primary energy use of the building is lower than the amount of renewable energy produced on the building or on its premises. Included are all basic services (heating, cooling, ventilation, hot water, auxiliary energy) and all specific services (lighting, equipment, elevators). The shell of the new building was specified as timber frame construction according to the Passive House Standard. The existing building will be improved in terms of energy efficiency. All kinds of measures will be taken to minimise energy consumption. Energy demand will be partially met using production waste heat combined with solar energy, wind power and groundwater. Also a compressed air reservoir for short term energy storage is planned. Electricity consumption for process energy will be included in the plus energy concept but implemented only if proved economical.
Methods and treatments
A core part of the concept is to provide printery and offices with energy services according to their demand. Passive house techniques are a proved and cost-efficient and can be specifically refined for printing facilities. In any case passive measures (saving of energy expenditure) are preferred to active measures (energy use).
By supplying air with displacement air diffusers air flow and thus air moistening can be minimised while air quality is improved in the occupational areas.
Remaining energy demand is met by sources that are available within the building (waste heat from printery processes, compressors, computer waste heat, heat and moisture recovery, daylight, geothermal heat) and locally (sun, groundwater, night cooling,wind ...). A detailled survey of the existing potentials has been conducted, which paid great attention to dynamic profiles, taking to great efforts for measurements and evaluation.
Also a compressed air reservoir for short term energy storage was studied and was found to be an interesting alternative in terms of energy but not yet in economic terms.
Mutual entanglement of demand and supply calls for new concepts for description of the dynamic character of the energy service, its resulting energy demand and coverage, and of the available supply of energy sources. While a Plus Energy Building should generate an energetic plus in an annual balance, we also studied in detail temporal variabilities of renewable energy and waste heat supply.
Heating and cooling panels are used to take advantage of small temperature differences using energy with small exergy content.
Cooling and heating energy is supplied generally as thermal energy, backed up for failure safety and for peak demand with" classical" but optimised vapor-compression refrigeration.
By storage and load management within the building premises a higher rate of energy self supply could be achieved.
A quantitative representation of demand and supply must display different time intervals in different design stages (hours, day/night, work week/weekend, seasons) to account for short-time fluctuations. Optimisation included the building as thermal store, two 10 m3 water tanks and preheating and pre-cooling of the building. A dynamic evaluation uses balances of final energy, primary energy demand and greenhouse gas potential.
The new building and the refurbished building stock meet Plus Energy Standard (excluding process energy but including conditioning and lighting of production facilities) with a 210 kWp installation and two small wind turbines à 15 kW. Due to savings in operating costs and with help of government aid (Umweltförderung) additional expenses related to the Plus Energy Standard reach pay off periods of 30 years but also of 15 years.
To cover also process energy demands by on-site production, another 300 kWp installation would be needed and could be accommodated on the premises.
Buildings are (at the design stage) carbon-neutral in terms of building operation, building materials production and repair/replacement and energy generating facilities.
Thomas Zelger, Wolfgang Huber, Felix Heisinger
Österreichisches Institut für Baubiologie und -ökologie Gmbh