Transient heat transfer and moisture load in cold attic constructions - A CFD analysis
Paper in proceeding, 2018

Mold growth in cold attic constructions has become an increasing problem in Sweden and other countries with cold climates due to the demands on energy efficient building envelopes. Highly insulated building envelopes with cold ventilated attics lead to colder climates in the attic space, which increases the risk for mold growth. In this paper, the transient heat transfer process including natural and forced convection is investigated for a 24-hour cycle in a virtual 3D model of a ventilated attic construction by the use of CFD technology. The momentum and energy equations along with the realizable k-epsilon turbulence model are solved with commercial CFD software. Transient simulations are performed for daily temperature variations for various ventilation rates and a hygrothermal analysis is conducted to estimate the risk for mold growth at the inner roof boundary. A virtual model of a ventilated attic with an underlying layer of porous medium is used for the simulations and the CFD approach is based on a validated model from previous research. The results are the temperature field and the risk for mold growth for different ventilation rates presented as a function of time during the cycle.

moisture load

cold attics

heat transfer

computational fluid dynamics (CFD)

building physics

fluid mechanics

Author

Vijay Shankar

Luleå University of Technology

Ragnar Hellsvik

Carl-Eric Hagentoft

Chalmers, Architecture and Civil Engineering, Building Technology

AIP Conference Proceedings

0094-243X (ISSN) 1551-7616 (eISSN)

Vol. 1978 470011
978-073541690-1 (ISBN)

International Conference of Numerical Analysis and Applied Mathematics, ICNAAM 2017
Thessaloniki, Greece,

Subject Categories

Applied Mechanics

Other Civil Engineering

Building Technologies

DOI

10.1063/1.5044081

More information

Latest update

1/18/2019