Effects of Visual Stimuli upon Thermal Sense under Air Conditioning in Summer

Kurazumi Y Fukagawa K

doi:10.4172/2165-7556.1000129

Abstract

Human thermal sense is not expressed only by simple heat equilibrium. The influence of visual and auditory stimuli causes differences in overall thermal sense arrived at by sophisticated sensory processing by the cerebrum. If it can be clearly shown that a thermal environment considered slightly uncomfortable could be ameliorated using visual stimuli, the cost effectiveness of such an initiative would be highly significant, particularly in terms of air conditioning system running costs. Focusing on the visual stimuli provided by greenery, experiments were conducted in a thermal environment deemed slightly uncomfortable, where the temperature was set at a base point of 28oC. Experiments were conducted in a temperature-controlled room. Thermal environmental conditions were set at three different temperatures: 25oC, 28oC and 31oC. Wall surface temperatures were set to equal these temperatures. Air velocity (calm air currents of 0.2 m/s or less) and relative humidity (60% RH) were set the same throughout. Subjects were asked to sit quietly for the test. The visual stimuli consisted of ten different types of scenery, including that of leafy vegetation. The influence of overall stimuli of the cerebrum on the indoor thermal environmental index ETF was determined to prove the significance of actively placing visual stimuli in spaces. Thermal stimuli influence the human body on mean skin temperatures, while visual stimuli do not affect mean skin temperatures. In ETF deemed fairly uncomfortable, that is at a range of hotter than 28-29oC, clear improvements were observed in thermal sense due to the influence of visual stimuli such as natural elements including vegetation like greenery. Visual stimuli were appropriate at a level of up to 69% greenery, where a dynamic effect on warmer environmental conditions can be felt and where the depth of fuller vegetation cover can be perceived.

Highlights

The Japanese people have long been attached to a way of life where they derive satisfaction from comfort obtained through subtle changes in their surroundings brought about by economizing
This research is to test subjects placed in a thermal environment deemed slightly uncomfortable, where the temperature is set at a base point of 28°C, to determine the influence of overall stimuli of the cerebrum on the indoor thermal environmental index ETF and to prove the significance of actively placing visual stimuli in spaces
Figures remained essentially stable throughout the entire period of testing, and it is believed that, in essence, environmental conditions were met.ETF is an indoor thermal environmental index based on human body heat balance

Summary

Introduction

The Japanese people have long been attached to a way of life where they derive satisfaction from comfort obtained through subtle changes in their surroundings brought about by economizing Changes such as the emergence of super-insulated housing and rising summer temperatures have resulted in higher indoor temperatures that cannot be addressed by these traditional cultural lifestyle values. In Japan, it is a commonly held belief that air conditioning systems should be set at 28°C in order to save energy. This may be highly beneficial and effective in private buildings where costs are paid for by the occupants. In public buildings, where behavioral thermoregulation is more difficult, this temperature setting can be inappropriate, potentially contributing to concentration problems and negatively influencing health

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