year month day
2016/
2 / 23

Department
Name

Environmental and Life Science
EngineeringID

Hiroshi Matsumoto

119405
Supervisor

Takanobu Inoue

DESTO JUMENO

Shigeru Kato
Abstract

Title

The Effects of Foliage Plants on Human Physiologicaland Psychological Responses and Productivity(800 words)

People spend a large amount of time in the workplace. In order to make their workplace more
pleasant people put plants such as flowers or foliage plants in their rooms. The main objective of
this study is to investigate the effects of indoor foliage plants on human physiological andpsychological responses and productivity. This objective is further divided into some sub-objectives
such as; 1) to investigate the characteristics of tasks in researches of the effects of foliage plants onhuman; 2) to investigate the effects of the number of indoor foliage plants on productivity, stressand attention; 3) to investigate effects of the number and size of foliage plants on mood,productivity, and perceived air quality (PAQ); 4) to investigate the effects of foliage plants,illuminances and task types on human impressions, stress and performance; 5) to investigate effects
of foliage plants on human physiological and psychological responses at different temperatures; 6)
to investigate the effects of foliage plants and lighting on human physiological and psychologicalresponses and productivity.
In Chapter 2, general factors that reside in the tasks used in researches of indoor foliage plants wereidentified. It is found that common characters of the task that foliage plants have affected inexperimental researches were task complexity, attention requirement, time pressure, difficulty,duration, creativity, and feedback. The task in foliage plants research should be moderate incomplexity, in the attention requirement, in task difficulty, and in task duration. It is also found thatfoliage plants have more effects on creative task than on short and repetitive work.
In Chapter 3, results of the study on the effects of the number of foliage plants on productivity,stress and attention were presented. It is found that there are significant effects of the number ofplants on friendliness, comfort, freshness, and cleanliness. In this experiment, the best number ofplants that should be placed in a room sized 9.53 m2 was seven.
In Chapter 4, the effects of the number and size of foliage plants on mood, productivity, and PAQ
were addressed. It is found that the increase in the number of plants could improve the occupant’smood. Secondly, the interaction between the number and size of foliage plants affected PAQ andreaction time. Increase of PAQ is related to the increase in the quantity of greenery up to a certain
number and size of the plants.
In Chapter 5, the effect of green coverage ratio (GCR) from the foliage plants and illuminance onperception, impressions, stress and relaxation were addressed. It is found that the impressions on

room conditions are increase with the GCR. Moreover, higher levels of illuminance produce better
pleasure, brightness, breeziness and quality impression. Also, the increase in GCR may decrease thelevel of stress and increase the level of relaxation, the performance on sudoku test and word creation
test.
In Chapter 6, the effect of foliage plants on human physiological and psychological responses atdifferent temperatures was addressed. In this study, we have investigated three levels oftemperatures within the range of comfort. Satisfactory results were found proving that the presenceof foliage plants at an appropriate temperature can induce better attention and meditation, which isuseful for increasing work performance and stress reduction.
In Chapter 7, the effects of foliage plants and illuminance on attention, stress and fatigue wereaddressed. It can be inferred that there is a significant effect of the interaction of the number andsize of plants on attention. The results show that the higher number of foliage plants produces better
quality impression, better perception of freshness and less boringness than smaller number of plants,
and it also can maintain alertness and attention. Moreover, it can be inferred that the presence ofplants at a higher illuminance reduces the heart rate, stress and fatigue.
To sum up, recommended room condition that would give optimal human responses andproductivity in a 9.5 m2 working room area are as follows: a room should be provisioned with 6
potted foliage plants, which height are between 25-50 cm, positioned in the front of the room
occupant, at his/her visual area. The potted plants can be placed on the desk or on the floor, depends
on its height. The working room temperature should be 25oC, and should be illuminated using 800lx
LED or fluorescent lamp.
Benefits for a company that can be obtained from the present of foliage plants by applying the above
recommended condition would be substantial. These include economical benefits through theincrease in employees’ productivity, product defective reduction and customer satisfaction. The
second benefit is the increase in employees’ health, thus reducing the company’s spending. Thethird benefit is energy saving. The next benefit is the increase in company’s “green” image.
Moreover, it may increase company’s share value.