Infiltration models and heat loss implications in office buildings
|Forfattere||Matthias Haase, Tore Wigenstad|
|Institusjon||Norwegian University of Science and Technology, Trondheim, Norway. and SINTEF Building and Infrastructure, Trondheim, Norway.|
|Nøkkelord||guidelines, layout, format, deadline, help|
|Redaktør||Vojislav Novakovic, Sten Olaf Hanssen, Hans Martin Mathisen|
AbstraktThe project’s principal objectives are to develop more energy-efficient building envelope assemblies and new methods for the design of building envelopes in harsh climates, resulting in more accurate and geographically dependent design guidelines. The project includes analyses of building envelopes applied in different kinds of climates, different uses, and different construction methods.
The total energy consumption is simulated for three different construction standards in different locations in Norway and the results are compared. First, energy budgets according to Norwegian regulations (TEK 2007) were calculated. Then, the energy saving potential of air tightness of the building envelope was evaluated. Here, different calculation methods for estimating energy use due to infiltration were applied, including simplified models and detailed advanced calculations taking site factors, building specific factors, and other climate conditions into account.
The results show that significant energy savings are possible with stricter air tightness of the envelope. The infiltration and related heat losses (and cooling demands) depend on the model used to predict this. Some models simplify infiltration and thus might give wrong suggestions for a building design. A careful consideration of climate related parameter is needed particularly for super-efficient envelope systems which can further enhance energy robustness, energy efficiency and comfort of the future building stock in Norway.
Air tightness of the building envelope is an important factor in energy efficient building design in Norway. However, traditional simplified methods that calculate infiltration rates related energy consumption can mislead in an early design stage by over or under estimating heating demand by up to 25%. Detailed calculations of site specific conditions are essential in order to optimize thermal building envelope design in cold climates like Norway.
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