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Publikācija: Heat Recovery Efficiency of Local Decentralized Ventilation Devices

Publication Type Scientific article indexed in SCOPUS or WOS database
Funding for basic activity Research project
Defending: ,
Publication language English (en)
Title in original language Heat Recovery Efficiency of Local Decentralized Ventilation Devices
Field of research 2. Engineering and technology
Sub-field of research 2.1. Construction and transportation engineering
Research platform None
RTU scientific equipment used for research
  • Ēku energoefektivitātes simulators.
Authors Jurģis Zemītis
Raimonds Bogdanovičs
Keywords Decentralized ventilation, Efficiency, Heat recovery, Pressure difference
Abstract Decentralized, room-based ventilation systems have become increasingly popular in the Baltic countries. Such systems are easy to install and, according to technical information, ensure high heat energy recovery potential for new and renovated buildings. The specified heat recovery efficiency is used for building energy simulations and to calculate the necessary heating energy that is needed to warm up the supply air. However, this value is stated at non-existent pressure difference between indoor of the building and the outside. In real-case situations, there is always some pressure difference due to wind and stack effect. In this study, a ventilation device is tested in a laboratory environment at different simulated outside air temperatures and pressure differences. The simulations are conducted in a climatic chamber where the air temperature and pressure differences can be set. The temperature is adjusted using a cooling device but the pressure difference with an exterior fan device. Different combinations of simulated outside air temperatures and pressure differences were tested. The results suggest that the heat recovery efficiency is highly dependent on the pressure difference and it rapidly decreases with the rise in pressure difference. If the pressure difference is in the range of 10-20 Pa, the heat recovery efficiency will be only between 20 and 50 %, while the stated value in the technical data sheet is 85 %. Even at a pressure difference of 0 Pa, the average heat recovery efficiency is 73 %, and only for the first few seconds of the supply cycle, the efficiency reaches 85 %. This can influence the calculated building energy efficiency class, as well as lead to undersized heating system elements.
DOI: 10.18720/MCE.94.10
Reference Zemītis, J., Bogdanovičs, R. Heat Recovery Efficiency of Local Decentralized Ventilation Devices. Magazine of Civil Engineering, 2020, Vol. 94, No. 2, pp.120-128. ISSN 2071-4726. Available from: doi:10.18720/MCE.94.10
Additional information Citation count:
ID 30913