LUBOŠ KRAJČI

Aeckerwiesenstrasse 26, 8400 Winterthur
Switzerland / Cellphone: +41 (0)78 747 13 88 / E-Mail: L.Krajci@soundtherm.ch

Professional strengths

  • Experienced building physics engineer.
  • Experience in low energy building design, moisture and humidity control inside of
    buildings
  • Extensive knowledge and experience in the areas of building acoustics,
    environmental acoustics and noise control.
  • Experience in measurement techniques and testing according to international
    standards as well as noise monitoring.
  • Collaboration with industry, research centers and universities.
  • Responsibility and leadership in multicultural and multilingual environments.
  • Experience of independent work roles as well as part of a team.

Employment

Shareholder, founded own company Soundtherm Ltd., consultancy of Building Physics focused
on building, room and environmental acoustics, energy consumption as well as heat transfer
and moisture.

  • Evaluated the energy consumption of buildings (energy balance, determination of
    energy losses, thermal bridges, U-Value calculations, sustainable energy gains)
  • Created thermal solutions and construction design to fulfill energy balance requirements
    (e.g. low energy or self-sufficient buildings)
  • Calculated steady state and non-stationary humidity and moisture transfer through external
    separating elements
  • Consulted with architects, private and public authorities concerning construction design
    and material properties in the field of the physics of buildings
  • Created acoustic solutions for the sound insulation of buildings (airborne, impact and
    structural noise)
  • Predicted and calculated sound insulation at the building planning stage and prescribed
    noise control measures
  • Environmental acoustic noise monitoring, noise mapping and noise control
  • Carried out field measurements in building, room and environmental acoustics

Acoustic consultant

  • Consulted with architects, private and public authorities concerning construction design
    and material properties in the field of the physics of buildings
  • Calculated acoustic solutions for the sound insulation of buildings (airborne, impact and
    structural noise)
  • Predicted and calculated environmental noise propagation and prescribed noise control
    measures
  • Environmental acoustic noise monitoring, noise mapping and noise control
  • Carried out field environmental noise monitoring

Acoustic consultant and commercial partner

  • Consulted with architects, private and public authorities concerning construction design
    and material properties in the field of the physics of buildings
  • Created acoustic solutions for the sound insulation of buildings (airborne, impact and
    structural noise)
  • Predicted and calculated sound insulation at the building planning stage and prescribed
    noise control measures
  • Environmental acoustic noise monitoring, noise mapping and noise control
  • Carried out field measurements in building, room and environmental acoustics

Head of the Building Acoustics Group, Laboratory for Acoustics/Noise Control

  • Led a research and technical team
  • Carried out field and laboratory testing according to international standards
  • Established collaboration between industry and research to drive application oriented
    research and product development
  • Promoted knowledge transfer to industry
  • Acquired a national research project NFP 66 and several knowledge transfer partnerships
    (KTP)
  • Supervised PhD students, master and bachelor students
  • Provided several expert witness opinions in the field of building and room acoustics
  • Designed and developed an unique multifunctional facility for testing of direct and flanking
    way sound transmissions in multifamily dwellings
  • Taught graduate students in the field of building acoustics at the Lucerne University of
    applied sciences and art, department of building technology and architecture.

Project references:

  • Acoustically optimised floor system made of hardwood with improved sound
    insulation below 100 Hz (National Research Program NFP 66 , Swiss National Research
    Foundation, Collaboration with ARU Liverpool Great Britain, UC Canterbury New Zealand and
    HSRO Rosenheim Germany)
    Development of a new floor system with improved sound insulation in the low frequency
    range and multifunctional optimisation in the field of Life Cycle Analysis (LCA).
    Website www.nfp66.ch
  • Sound insulation in timber based structures and buildings
    (Research Project funding by Federal Office for the Environment FOEN)
    Development of lightweight/heavyweight separating elements and their junctions with
    reduced flanking transmissions. Website www.lignum.ch (only in German
    or French language)

Professional Associations

  • SIA Member
  • Member of Technical Committee CEN/TC126/WG2 –Building Acoustics of the
    European Committee for Standardization CEN, Brussels
  • Member of the Swiss Acoustical Society SGA-SSA.
  • Member of the Association Minergie Switzerland
  • GEAK Expert
  • Member of the Acoustical Society New Zealand
  • Member of the Institution of Professional Engineers New Zealand

Selected Publications

  • Krajči, L., Keller, B. und Walk, M.: Hochschalldämmende Holzdecken,
    11. bauakustisches Symposium 2002, Dresden (D)
  • Krajči, L.: Dissertation: ’Impact sound insulation measurements of wooden
    construction based on modal analysis using Frequency Response Function FRF’;
    Technische Universität SK-96001 Zvolen, Slowkei (SK), 2004
  • Churchill C., Hopkins C., Krajči L. 2011 -Modelling airborne sound transmission
    across a hybrid heavyweight-lightweight floor using Statistical Energy Analysis,
    Forum Acousticum 2011, European Acoustics Association, ISBN: 978-84-694-1520-7,
    ISSN: 221-3767
  • Krajči, L., Hopkins, C., Davy, J.L., and Tröbs, HM.: Airborne sound transmission of a
    cross-laminated timber plate with orthotropic stiffness; Euronoise 2012 Prag; pp.
    202–207, Invited; PACS no. 43.55.Rg, 43.55.Ti, 43.40.Rj, 43.20.Rz.; ISSN 2226-5147;
    ISBN 978-80-01-05013-2
  • Geyer, Ch., Tröbs, HM.; Bütikofer; R.; Krajči, L.: Measurements of flanking
    transmissions using a newly developed radiation efficiency measurement method in
    a flanking transmission suite; Euronoise 2012 Prag; pp. 677–681, Contributed; PACS
    no. 43.55.Rg, 43.55.Ti, 43.40.Rj, 43.20.Rz.; ISSN 2226-5147; ISBN 978-80-01-05013-2
  • Mahn, J., Hopkins, C., Schanda, U., Krajči, L.: Competitive wooden floor systems –
    multi-objective optimization based on acoustics improvement, Internoise 2013
    Innsbruck, Austria 2013
  • Mahn, J., Filippoupolitis, M., Hopkins, C., Völtl, R., Schanda, U., Krajči, L.:
    The Optimization of a Wooden Floor Design Based on Validated Finite Element
    Models, Internoise 2014 Melbourne Australia 2014
  • Filippoupolitis, M., Hopkins C., Völtl, R., Schanda, U., Mahn, J., Krajči, L.:
    Experimentally validated finite element models for the modal response of a solid
    timber floor formed from dowel–connected joists, Forum Acusticum, Krakow, Poland
    2014
  • Davy, J.L., Mahn, J., Krajči, L., Wareing, R. and Pearse, J.: Comparison Of Theoretical
    Predictions Of Radiation Efficiency With Experimental Measurements, ICSV22 2015,
    International Congress on Sound and Vibration, Florence, Italy 2015
  • Hopkins C., Filippoupolitis, M., Ferreira, N., Völtl, R., Schanda, U., Mahn, J., Krajči, L.:
    Vibroacoustic finite element modelling of the low-frequency performance of a solid
    timber floor formed from dowel-connected joists, Internoise 2016, Hamburg 2016
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