Hviid, Christian Anker

Svendsen, Svend

Online Research Database In Technology

                       General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights.  • Users may download and print one copy of any publication from the public portal for the purpose of private study or research. • You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal   If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim.     Downloaded from orbit.dtu.dk on: Dec 17, 2017Passive ventilation systems with heat recovery and night coolingHviid, Christian Anker; Svendsen, SvendPublication date:2008Link back to DTU OrbitCitation (APA):Hviid, C. A., & Svendsen, S. (2008). Passive ventilation systems with heat recovery and night cooling. Postersession presented at 29th Advanced Building Ventilation and Environmental Technology for Addressing ClimateChange Issues, Kyoto, Japan.Conclusion   The simulations performed in this paper indicate that passive ventilation has potential over conven-tional mechanical ventilation  In conjunction with adequate night cooling both ventilation and cooling tasks are performed satisfac-torily. Consequently energy consumption for fans and mechanical cooling can be saved in a passive ventilation system  If the system is equipped with low pressure loss heat recovery and electrostatic filtering it may per-form the task of ventilation, cooling and heating in high performance offices with comparable flexibil-ity and total costs to that of conventional mechanical systems Introduction   Passive in this context means ventilation solutions that exploit natural driving forces and the building envelope physics to establish and maintain a satisfying indoor climate without the consumption of electrical energy.  The concept has particular potential in temperate climates with moderate wind velocities and large daily temperature differences   Input   Building simulation program ESP-r   Cross section with rectangu-lar 2:1 footprint  Façades oriented N/S  Transparent façade: 40%  Heavy deck construction  Light internal partitions  Automatic 3-step solar shading in interval 23-26°C  Internal loads during office hours from people 5 W/m2, equipment 4 W/m2, lighting 7 W/m2  Coupled energy and air flow network in simulation  Heat exchangers with total pressure drop of 1.3 Pa  Intake duct size: Ø 1000mm  Room supply duct: Ø 250mm Discussion   Sufficient comfort ven-tilation during cold sea-son  Sufficient cooling power  by night cooling during hot season...  ...but comfort ventila-tion must be provided by natural ventilation  Energy savings of 40%if proper damper con-trol is applied to venti-lation intake  Air distribution has to be investigated further  Results   Figure 1 depicts the whole-year ventilation rate through the main supply duct.   Figure 2 depicts duration curves of ventilation rate for critical rooms during the heating season filtered by occupancy.  Figure 3 depicts whole-year duration curves of indoor air tem-perature in critical rooms filtered by occupancy.  A passive ventilation system with heat recovery and night cooling Areas of expertise:  Energy efficiency and optimization  Ventilation  Indoor climate  Integrated design  Total costs calcula-tions Christian Anker Hviid  Industrial PhD student  M.Sc. Work Space Design ALECTIA A/S Teknikerbyen 34, DK-2830 Virum  Phone dir.: +45 88 191 365 Cell: +45 40 879 749 E-mail: crh@alectia.com   Passive ventilation system   Low energy consumption  Equal or better indoor cli-mate compared to me-chanical ventilation  Low total costs  Flexible solutions  Does not occupy more space than conventional mechanical ventilation   Indoor climate class II ac-cording to CEN15251: 7l/s per person     Heating season Summer   Work hours Outside work h. Work hours Outside work h. Passive system On Off Off On Openings in façade Off Off On Off Activation of passive system and windows  Primary energy kWh/m² Mech. vent. and cool. Passive vent., night cool., mech cool. Heating 100 % 103 % Cooling 100 % 55 % Fans 100 % 0 % Lighting 100 % 100 % Hot water 100 % 100 % Total 100 % 60 % Danish Building Code 2006 2010 100% 53% Heat exchanger Heat exchanger Water circuit Pump Office Displacement diffusor  Intake Exhaust Electrostatic precipitator  Fig. 3 Fig. 2 Technical University of Denmark Fig. 1 

Passive ventilation systems with heat recovery and night cooling

In building design the requirements for energy consumption for ventilation, heating and cooling and the requirements for increasingly better indoor climate are two opposing factors. This paper presents the schematic layout and simulation results of an innovative multifunc-tional ventilation concept with little energy consumption and with satisfying indoor climate. The concept is based on using passive measures like stack and wind driven ventilation, effective night cooling and low pressure loss heat recovery using two fluid coupled water-to-air heat exchangers developed at the Technical University of Denmark. Through building integration in high performance offices the system is optimized to incorporate multiple functions like heating, cooling and ventilation, thus saving the expenses of separate cooling and heating systems. The simulation results are derived using the state-of-the-art building simulation program ESP-r to model the heat and air flows and the results show the feasibility of the proposed ventilation concept in terms of low energy consumption and good indoor climate

                       General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights.  • Users may download and print one copy of any publication from the public portal for the purpose of private study or research. • You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal   If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim.     Downloaded from orbit.dtu.dk on: Dec 17, 2017Passive ventilation systems with heat recovery and night coolingHviid, Christian Anker; Svendsen, SvendPublished in:Proceedings of the 29th AIVC Conference in 2008Publication date:2008Link back to DTU OrbitCitation (APA):Hviid, C. A., & Svendsen, S. (2008). Passive ventilation systems with heat recovery and night cooling. InProceedings of the 29th AIVC Conference in 2008: Advanced building ventilation and environmental technologyfor addressing climate change issues (Vol. 1, pp. 99-104). Kyoto: National Institute for Land and InfrastructureManagement, Japan. !""!  !#$$!  !#$#!  !#$%!  !#$&!  !#$'! 

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Passive ventilation systems with heat recovery and night cooling

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Online Research Database In Technology

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