Page 26 - ZEB Final Report 2009-2017

26 | ZEB Zero Emission Buildings | Final Report 2017

Vojislav Novakovic Jens Tønnesen Thorhildur Fjola
Professor, Department PhD Candidate Kristjansdottir
of Energy and Process ZEB, Department of PhD Candidate, ZEB,
Engineering, NTNU Energy and Process Department of Architecture
Engineering, NTNU and Technology, NTNU

New Methods

for Ventilation

Systems

A new method achieves optimal design of

ventilation systems for ZEBs – with minimum

overall environmental impact.

The design of buildings and technical the existing ductwork. Calculations are the use of materials which are needed
installations is a creative process aiming made with the average environmental for constructing the entire ductwork
at constructing systems that fulfill given impact of electricity generation over the and the electrical energy which the fan
requirements in an optimal manner. next 30 years of 0.3 kg CO2-equivalents/ requires to overcome the pressure drop
To achieve this, the design team uses kWhel. through the ventilation systems over the
a comprehensive calculation toolbox Optimization is a complicated entire lifetime. To provide input for the
equipped with different simulation process of balancing between several optimization, it was necessary to create
and optimization software. In ZEBs, competing factors. As regards ventilation data for the environmental impact (the
the requirement is minimum overall systems, small duct sizes require less life cycle inventory data) for circular
environmental impact of greenhouse gas material, ductworks conflict less with the ducts, 90° bends, connections, VAV
emissions from all embedded materials, building construction and usually reduce dampers, silencers, and air diffusers.
in addition to energy used for operation investment costs. However, the pressure
over the entire lifetime. drop increases, which consequently
The optimization technique «genetic demands greater electricity use for the Further reading: Tønnesen, J. and T.
algorithm» is applied on a case ventilation operation of the fan. Larger ducts affect Kristjansdottir. Life cycle approach as a
method for optimizing building services
system found in an existing passive office required installation heights and thus systems in extremely low energy buildings.
building. The optimized solution reduces need increased floor height and extra In Sustainable Built Environment Conference
the environmental impact (kg CO2 façade material. 2016 in Hamburg : Strategies – Stakeholders
– Success factors. 2016. ZEBAU, Hamburg.
equivalents) of ductworks by 16% and the The optimization method includes https://publikationen.bibliothek.kit.
energy use of fans by 25% compared to the environmental impact from both edu/1000051699