TY - JOUR
T1 - A computational analysis of effective R-values of buried ducts–the dynamic performance of buried ducts
AU - Pallin, Simon
AU - Salonvaara, Mikael
AU - Evans, Rebecca
N1 - Publisher Copyright:
© Copyright © 2024 ASHRAE.
PY - 2024
Y1 - 2024
N2 - This paper evaluates the thermal performance of ducts partially or fully buried in loose-fill attic insulation. The overall thermal resistance between the ducts and the attic is referred to as an effective R-value. This paper shows a strong dependency of assumed attic temperature on the effective R-value. Based on the results, the effective R-value can be about twice as much with an attic temperature of 130 °F [54.4 °C], compared to when the attic temperature is 80 °F [26.7 °C]. Thus, this paper provides a polynomial regression equation based on a large set of simulations to determine the effective R-value of buried ducts depending on attic temperature and whether the HVAC system runs in cooling or heating mode. Further, the work presented in this paper investigated the potential impact of convective airflow within the attic insulation, particularly around the ducts. The analysis was based on computational fluid dynamics (CFD) and indicated that convectional forces are presented around the exterior surface of the ducts, but with negligible impact on the overall heat balance between the duct and the attic space.
AB - This paper evaluates the thermal performance of ducts partially or fully buried in loose-fill attic insulation. The overall thermal resistance between the ducts and the attic is referred to as an effective R-value. This paper shows a strong dependency of assumed attic temperature on the effective R-value. Based on the results, the effective R-value can be about twice as much with an attic temperature of 130 °F [54.4 °C], compared to when the attic temperature is 80 °F [26.7 °C]. Thus, this paper provides a polynomial regression equation based on a large set of simulations to determine the effective R-value of buried ducts depending on attic temperature and whether the HVAC system runs in cooling or heating mode. Further, the work presented in this paper investigated the potential impact of convective airflow within the attic insulation, particularly around the ducts. The analysis was based on computational fluid dynamics (CFD) and indicated that convectional forces are presented around the exterior surface of the ducts, but with negligible impact on the overall heat balance between the duct and the attic space.
UR - http://www.scopus.com/inward/record.url?scp=85200115681&partnerID=8YFLogxK
U2 - 10.1080/23744731.2024.2363103
DO - 10.1080/23744731.2024.2363103
M3 - Article
AN - SCOPUS:85200115681
SN - 2374-4731
JO - Science and Technology for the Built Environment
JF - Science and Technology for the Built Environment
ER -