The Effect of Solar Reflective Cover on Soak Air Temperature and Thermal Comfort of Car Parked under the Sun

Abstract

Parking a vehicle under the sun for a short period of time can rapidly increase the interior air cabin temperature no matter in clear sky days or even in partially cloudy days. These circumstances can be anxieties to car occupants upon entry. The aim of this paper is to evaluate experimentally the effect of solar reflective cover (SRC) on vehicle air temperature and cabin thermal comfort. Experimental measurements of parked cars were conducted in UKM, Bangi city, Malaysia (latitude of 2.9° N and longitude of 101.78° E) under partially cloudy day where average ambient temperature is 33 o C. The experimental measurements cover the following cases: case (I): car with/ without SRC (at different measurement time); Case (II): using two identical cars concurrently (SRC versus baseline); Case (III): using two identical cars concurrently (solar reflective film (SRF) versus baseline) and Case (IV): using two identical cars concurrently (SRF versus SRC). Experimental results dedicated to case (I) revealed that the maximum cabin air temperature with SRC (39.6 o C) is significantly lower than that of baseline case (57.3 o C). This leads to temperature reduction improvement of 31% and the difference between the cabin and the ambient air temperature was minimized by approximately 73%. In addition, the results revealed that the air temperature at breath level of car with SRC dropped to comfort temperature (27 o C) after 7 min while baseline car reached comfort temperature after 14 min. Results of the other cases are discussed inside the paper. Overall, it is learned that SRC is found superior as an efficient thermal insulation system limits solar radiation transmission into the cabin through the glass; keeps cabin air temperature close to the ambient temperature; and provide acceptable thermal environment to the occupants as they settle into their parked car.Keywords: parked vehicle under the sun, cabin soak air temperature, solar reflective aluminum cover, cabin thermal comfort.

Measurement of airborne emissions from extinguished cigarettes:

“…It is noteworthy that the 24 h emitted mass for nicotine from a cigarette butt could be up to 15 % of the emitted mass from a burning cigarette. Hence, the long-term emitted mass could be comparable to mainstream and sidestream smoke if the cigarette butt were left longer than 24 h in a room or at higher temperature (e.g., in a car, where the temperature can be over 55 °C (Lahimer et al 2017).…”