TY - GEN
T1 - New calculation method to solve moisture balance in the room with regenerator heat recovery and infiltration
AU - Pomianowski, Michal Zbigniew
AU - Heiselberg, Per
AU - Drivsholm, Christian
N1 - Conference code: 11
PY - 2017
Y1 - 2017
N2 - This paper investigates moisture related performance of a regenerator heat exchanger located in a decentralized ventilation unit for residential building application. The decentralized ventilation solutions have recently become a more and more popular alternative to centralized ventilation systems. Due to the small space available and in order to avoid maintenance of these types of units, they are equipped with regenerator heat exchanger in some cases. In the recent past and also presently, Building Regulations (BR) and European directives have increased demands for heat recovery efficiency in air handling units (AHUs). In the case of regenerator heat exchanger, the higher the heat recovery efficiency obtained the higher risk that condensation might occur. This condensation might form small droplets on the surface of the regenerator that might not be possible to drain in the short switching time of the regenerator and consequently might be evaporated in the next cycle back to the building and cause elevated humidity conditions in the indoor spaces. Due to the fact that the traditionally used dilution equation must not be used to solve moisture balance in the room with regenerator heat exchanger and infiltration, this paper presents a new calculation methodology that takes into account infiltration, condensation in the regenerator, and back evaporation to the room. The paper compares humidity levels in the room ventilated with regenerator heat exchanger and ordinary counter-flow exchanger. Theoretical calculations indicate that the ability of a ventilation system with regenerator to remove moisture from the room is very dependent on moisture loads in the room, air change rate, and infiltration rate.
AB - This paper investigates moisture related performance of a regenerator heat exchanger located in a decentralized ventilation unit for residential building application. The decentralized ventilation solutions have recently become a more and more popular alternative to centralized ventilation systems. Due to the small space available and in order to avoid maintenance of these types of units, they are equipped with regenerator heat exchanger in some cases. In the recent past and also presently, Building Regulations (BR) and European directives have increased demands for heat recovery efficiency in air handling units (AHUs). In the case of regenerator heat exchanger, the higher the heat recovery efficiency obtained the higher risk that condensation might occur. This condensation might form small droplets on the surface of the regenerator that might not be possible to drain in the short switching time of the regenerator and consequently might be evaporated in the next cycle back to the building and cause elevated humidity conditions in the indoor spaces. Due to the fact that the traditionally used dilution equation must not be used to solve moisture balance in the room with regenerator heat exchanger and infiltration, this paper presents a new calculation methodology that takes into account infiltration, condensation in the regenerator, and back evaporation to the room. The paper compares humidity levels in the room ventilated with regenerator heat exchanger and ordinary counter-flow exchanger. Theoretical calculations indicate that the ability of a ventilation system with regenerator to remove moisture from the room is very dependent on moisture loads in the room, air change rate, and infiltration rate.
KW - Regenerator heat exchanger
KW - Decentralized ventilation
KW - Moisture balance
KW - Condensation
KW - Regenerator heat exchanger
KW - Decentralized ventilation
KW - Moisture balance
KW - Condensation
U2 - 10.1016/j.egypro.2017.09.659
DO - 10.1016/j.egypro.2017.09.659
M3 - Conference article in Journal
SN - 1876-6102
VL - 132
SP - 135
EP - 140
JO - Energy Procedia
JF - Energy Procedia
IS - October 2017
T2 - 11th Nordic Symposium on Building Physics
Y2 - 11 June 2017 through 14 June 2017
ER -