Experimental validation and model development for thermal transmittances of porous window screens and horizontal louvred blind systems

TitleExperimental validation and model development for thermal transmittances of porous window screens and horizontal louvred blind systems
Publication TypeJournal Article
Year of Publication2017
AuthorsRobert Hart, Howdy Goudey, D. Charlie Curcija
JournalJournal of Building Performance Simulation
Volume11
Issue2
Pagination190 - 204
Date Published05/2017
ISSN1940-1493
KeywordsBuilding energy, Heat Transfer, shading, u-factor, window attachment, windows
Abstract

Virtually every home in the US has some form of shades, blinds, drapes, or other window attachment, but few have been designed for energy savings. In order to provide a common basis of comparison for thermal performance it is important to have validated simulation tools. This paper outlines a review and validation of the ISO 15099 centre-of-glass thermal transmittance correlations for naturally ventilated cavities through measurement and detailed simulations. The focus is on the impacts of room-side ventilated cavities, such as those found with solar screens and horizontal louvred blinds. The thermal transmittance of these systems is measured experimentally, simulated using computational fluid dynamics analysis, and simulated utilizing simplified correlations from ISO 15099. Correlation coefficients are proposed for the ISO 15099 algorithm that reduces the mean error between measured and simulated heat flux for typical solar screens from 16% to 3.5% and from 13% to 1% for horizontal blinds.

DOI10.1080/19401493.2017.1323010
LBNL Report Number

LBNL-2001141

Short TitleJournal of Building Performance Simulation