Fraunhofer Institute for Building Physics IBP
Noise reduction in ventilation and air conditioning technology
Energy consumption and noise generation of ventilation systems are evaluated differently depending on the point of view or point of time. As concerns the decision for investments, a reduction in energy consumption is an obvious reason for amortization. The expenditure for noise reduction, however, is "only" cost-intensive. After a certain period of operation, the assessment is often reversed. Users of ventilated rooms or neighbors of industrial ventilation systems may be aware of the energy efficiency, yet the ventilation noise represents an acute and chronic nuisance.
Noise and acoustic environmental conditions have an impact on health, well-being and performance in working and living spaces. Just as with the other room characteristics of light, climate and air quality, guidelines and standards must therefore be observed. While energy saving lamps and energy-efficient air conditioning systems are a matter of course, there is still a significant potential for savings with sound-reducing components. They are obstacles to air circulation and to overcome them costs energy in form of increased fan power. The relation of savings potential to size of the system is not constant, since the great variety of systems entails both acoustic and energy differences. The energy savings reservoir, however, covers all systems and many components, from filters, heat exchangers and fire dampers to the actual silencers.
A practical example: Only by replacing conventional silencers by innovative silencers developed by the Fraunhofer IBP was it possible both to reduce noise pollution in a large industrial exhaust ventilation system and to achieve annual energy savings of more than 500,000 euros. Innovative silencers thus combine a high, adapted noise attenuation effect with low pressure loss. The high amount in this example plant is certainly exceptional due to the plant dimensions, but systematic and cost-effective synergy effects can also be achieved on a small scale A look at many existing systems confirms that the balance of additional technical expenditure and the added value resulting from acoustic and energy efficiency improvements is already positive with regard to current energy prices.
Energy savers and hearing protectors also need the tools for planning and design. With the software program “compas" (Computation of Absorptive Silencers) of the Fraunhofer IBP, silencers can be designed and optimized acoustically and energetically on the PC. This is also a way of energy saving in peace and quiet.