Thermal performance modelling of complex fenestration systems

Abstract

/npsi/ctrl?lang=en http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/ctrl?lang=fr Access and use of this website and the material on it are subject to the Terms and Conditions set forth at http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/jsp/nparc_cp.jsp?lang=en NRC Publications Archive Archives des publications du CNRCThis publication could be one of several versions: author's original, accepted manuscript or the publisher's version. / La version de cette publication peut être l'une des suivantes : la version prépublication de l'auteur, la version acceptée du manuscrit ou la version de l'éditeur. For the publisher's version, please access the DOI link below./ Pour consulter la version de l'éditeur, utilisez le lien DOI ci-dessous.http://dx.doi.org/10. 1080/19401490903046785 Journal of Building Performance Simulation, 2, 3, pp. 189-207, 2009-09-01 Thermal performance modeling of complex fenestration systems Laouadi, A. The methodology assumes each system layer as porous with calculated effective radiation and thermal properties. A new thermal penetration length model was developed to account for the effects of porous layers on the convective film coefficients of adjacent gas spaces, and applied to various types of shading devices. This methodology is validated using the available measurement and CFD simulation results for the U-factor of double-glazed windows with between-pane and internal blinds.

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

“…Exterior mount blind configurations show good agreement between the proposed WINDOW model and previous studies by Shahid (2005), Naylor (2006), and Laouadi (2009). Agreement is also good with EN 13125 for fully-tilted high-emissivity slats.…”

“…Existing experimental work includes Clark et al (2013), Collins and Harrison (2004a), Cuevas et al (2010), Fang (2000), Garnet et al (1995), Naylor et al (2002a), and Naylor et al (2002b). Simulation and simplified model development is included in the work of Ye et al (1999), Laouadi (2009), Naylor and Shahid (2006), Marjanovic et al (2005), Oosthuizen et al (2005), Roelevelld et al (2010), Shahid and Naylor (2005), Collins (2004), and Wright (2008). Additional work involving SHGC of blinds under solar load has been done by Collins andHarrison (1999, 2004b), Harrison and van Wonderen (1998), Kotey et al (2009), andTait (2006).…”

“…Horizontal blind products typically have very high dsurface  .99 when slats are horizontal and greater than dsurface  .70 percent when fully tilted. For porous screens and horizontal blind products with a natural convection boundary condition typical of room-side mount shades, Laouadi (2009) proposed a model based on penetrative convection in porous media, from Bejan (2004). The proposed models from Laouadi, Wright (2008), and others are founded on an adjustment of the glass-to-shade cavity depth, dgap, as a function of slat width, pitch, and/or openness.…”

A simplified model of heat transfer at an indoor window glazing surface with a Venetian blind

“…The current model assumes constant temperatures in between the blind slats and window surface without any consideration of the mean air velocity. Another model based on the ISO 15099 standard has been developed by Laouadi (2009). His model expands on the ISO 15099 standard by using porous media equations to improve the convective and radiative heat transfer models of various layers inside the fenestration system.…”

Numerical and experimental validation for the thermal transmittance of windows with cellular shades

“…Collins and Wright (1998) showed that early implementations of this model incorrectly accounted for IR transmission through layers, but this has since been corrected in the WINDOW software. Laouadi (2009) expanded on the van Dijk/ISO 15099 model by adding product type specific correlations for equivalent properties, flow between layers, and surface coefficients.…”