Effect of Glazing Thermal Conductivity on Cabin Soak Temperature SABIC Innovative Plastics

Format:

Conference/Event

Author/Creator:

Gasworth, Gasworth, author.

Contributor:

Tankala, Triloka

Conference Name:

SAE 2012 World Congress & Exhibition (2012-04-24 : Detroit, Michigan, United States)

Language:

English

Physical Description:

1 online resource

Place of Publication:

Warrendale, PA SAE International 2012

Summary:

Previous papers by the present authors described use ofcomputational fluid dynamics (CFD) to quantify the effect ofglazing thermal conductivity on steady-state heating, ventilationand air-conditioning (HVAC) load under wide-ranging climate andstate of motion scenarios, and to estimate the significance of thiseffect for electric battery performance. The CFD simulationsyielded the total heat transfer between the ambient and the cabinof a model car, including radiative and convective heat transfer.The five-fold lower inherent thermal conductivity of polycarbonaterelative to glass was found to reduce steady-state HVAC load byseveral percent in all scenarios, leading to reduced greenhouse gasemission or increased electric range, according to the type ofvehicle.This paper complements the previous study by quantifying throughsimulation the effect of glazing thermal conductivity on cabin soaktemperature, the latter reflecting a balance between radiative andconvective heat transfer in a closed, unventilated, parked car withHVAC off, in a hot, sunny environment. Soak temperature has been afocus in the regulatory arena as an initial condition in proposedtests of air-conditioning contribution to tailpipe emissions. Twoglazing configurations are simulated: a baseline configuration withglass at all locations, and a reduced thermal conductivityconfiguration with polycarbonate glazing substituted at thebacklite and rooflite. A difference in soak temperature of lessthan 1°C is found for the two glazing configurations under theconditions of relatively high solar radiation and ambienttemperature in Phoenix, Arizona at mid-day in June. This differenceis small compared to both the soak temperature relative to theambient and the variation in soak temperature found for a range ofoptical and heat transfer parameters for non-glazing elements ofthe cabin. The insignificance of glazing thermal conductivity forsoak temperature is reconciled with its significance for steadystate HVAC load in terms of air movement at the inside and outsideglazing surfaces

Notes:

Vendor supplied data

Publisher Number:

2012-01-1207

Access Restriction:

Restricted for use by site license