An Assignmentonthermal Comfort and the Use of Courtyards in Residential

AN

ASSIGNMENT

ON

THERMAL COMFORT AND THE USE OF COURTYARDS IN RESIDENTIAL BUILDINGS

IN

AKURE

BY

AJIBADE ADETUNJI OLAOLUWA

ARC/10/3677

COURSE CODE / TITLE:

ARC 810-APPLIED CLIMATOLOGY

COURSE LECTURER

PROF. O. O. OGUNSOTE

SEPTEMBER, 2011.

TABLE OF CONTENTS

Pages

Title page i

Table content ii

Abstract 2

1.0  Introduction 3

2.0  Thermal Comfort 4

2.0.1 Why is thermal comfort significant in Akure? 4

3.0. Courtyards 5 3.0.1 Courtyard design 5

4.0 Uses of courtyards in residential buildings in Akure 6

4.0.1 Effects of natural ventilation of thermal comfort 7

4.0.2 Factors affecting thermal comfort of courtyard buildings in Akure 7

5.0 Conclusion 8

ABSTRACT

This term paper qualitatively identifies the thermal comfort and the use of courtyards in residential houses in Akure, Ondo state, located in the South western part of Nigeria with its geographical coordinates are 7° 15' 0" North, 5° 12' 0" East. According to architectural design recommendations, Akure is situated in the Coastal Design Zone (Ogunsote and Prucnal-Ogunsote, 2002b, 2002c). It measures elements of courtyard housing style and consequently how they adapt to the environmental climate to improve the thermal comfort within the building. Several studies have shown lately that the international comfort standards for buildings and the related predictions models report a warmer sensation than the occupants report in the case of naturally ventilated buildings in warm climates.

This paper discusses the thermal comfort in a building with a courtyard incorporated into its design improve thermal comfort within the spaces of the building.

1.0  INTRODUCTION

Maintaining this standard of thermal comfort for occupants of buildings or other enclosures is one of the important goals of building design. Thermal comfort is maintained when the heat generated by human metabolism is allowed to dissipate, thus maintaining thermal equilibrium with the surroundings. Courtyards have been used to improve the thermal comfort within the building fabric.

Akure, the capital of Ondo state also known as the ''Sunshine state'' is known for its high temperature for most parts of the day during a longer part of the year.

Therefore, thermal comfort is of great importance to the users of the building there.

Thermal Comfort and particularly comfort models for naturally ventilated buildings located in warm and humid areas like Akure are topics of wide discussion because of their importance in the design of energy-efficient building.

Akure is in a coastal climatic zone and the use of courtyard is prominent in some of the ancient and modern buildings, most especially, residential buildings. This is due to the warm and humid nature of the coastal climatic zones.

2.0  THERMAL COMFORT

There is no absolute standard of thermal comfort. This is not surprising, as humans can and do live in a range of climates from the tropics to high latitudes. An Internationally-accepted definition of thermal comfort is ‘that condition of mind which expresses satisfaction with the thermal environment (British Standard BS EN ISO 7730).

In simpler terms, ‘thermal comfort’ depicts an individual’s psychological state of mind. It is usually referred to in terms of whether someone is experiencing hotness or too coldness.

Thermal comfort is very difficult to define because you need to take into account an array of environmental and delicate factors when deciding what will make people feel comfortable. These factors make up what is known as the ‘human thermal environment’.

1.0

2.0.1 Why is thermal comfort significant in Akure?

As thermal comfort is psychological, it may affect our overall self-confidence. Akure falls within a coastal climatic zone and generally warm and humid for most part of the year. Employee complaints may increase, productivity may fall and in some cases people may refuse to work in a particular environment

3.0 COURTYARDS

A courtyard is defined as a part of a building which is open to the sky. It is well lit and airy. Courtyards aid air movement within the building by providing the necessary space for escape of used air and replacement with outside air.

3.0.1 Courtyard Design

The traditional houses (ile) in Akure had a rectangular plan. A single entrance gate gave access to a number of inner courtyards. They formed a series of separate apartments occupied by closely and usually patrilineal-related families ranked according to seniority. There were still larger compounds containing a group of ile, called agbo-ile or agbole (Denyer, 1978; Dmochowski, 1990).

The courtyard designs of the modern houses in Akure are more elegant in design usually for more than just ventilation purposes and some have designs of different shapes like existing in the form of circles, squares and other polygons. These buildings were able to respond to the severe weather conditions by using steep roofs, deep overhangs, courtyards and thick adobe walls. They also responded well to the cultural needs of the people. Several studies have shown that there are some non-quantifiable elements of comfort that influence the thermal sensation. These elements include culture, habits and traditions, mental states and expectations of the inhabitants of these buildings and they can mutually or independently vary the level of tolerance toward certain thermal conditions.

Fig 1: A modern day residential courtyard in Akure used for different purposes

4.0. USE OF COURTYARDS IN RESIDENTIAL BUILDINGS IN AKURE

The improvisation of courtyards into the architecture of buildings in Akure, South-western Nigeria is a very efficient and inexpensive technique of making sure thermal comfort is achieved naturally at all times. Sadly, in Nigeria these days electric power supply has been most erratic compared to the past. Most people, (Akure inhabitants not excluded) do not have deep pockets to purchase private power generating plants or generators.

Courtyards have been most efficient in making sure that the movement of air within other spaces in the building. These courtyards are introduced into various buildings types to ease discomfort. In the most of residential areas around Oba Adeshida road, the buildings here are erected very closely together causing thermal discomfort during the hot periods of the day. Other factors influencing thermal comfort also come into play increasing or decreasing the comfort of buildings.

4.0.1 Effects of natural ventilation of thermal comfort

Recently, with the current energy crisis and financial situation in the city of Akure, natural ventilation is being used for indoor temperature control. This process can make the controlled indoor air temperature more vulnerable to the outdoor weather, and during the seasonal months the temperatures inside can become too extreme. During about eleven months of the year, the temperature inside can rise too high and cause the need for open windows and fans to be used. The courtyards would be more appreciated at these times of the year.

4.0.2 Factors affecting thermal comfort of courtyard buildings in Akure.

The thermal comfort of typical coastal climatic zone (e.g. Akure) courtyard buildings depends hugely on these factors.

Firstly, is the thermal mass of the building for the amount that the temperature fluctuates and by how many degrees, and at what hours it reaches highs and lows. The materials used in building these houses have a significant part to play in the thermal comfort of occupants in the building. Sand-crete block walls allow faster thermal balance between the courtyard and the spaces surrounding it. The sizes of openings also are a contributing factor.

Secondly, it depends on the individual participation of the building's inhabitants. This include activities like watering the courtyard, opening and shutting shading devices and windows, and fine-tuning one's own clothing and activity level. Cooking also increases the level of thermal discomfort in these buildings due to poor designs in some cases.

And third, it depends on accepting less thermal control than would be possible with today's air conditioning equipment.

5.0 CONCLUSION

Thermal comfort is essential in residential buildings. It promotes good health and comfort. Courtyards have been employed to improve thermal comfort in Akure residents and it has proven to be a sure way of achieving comfort for the building users. It has also been observed that thermal comfort of employees in places of work is necessary to impact positively on productivity.

REFERENCES

Ogunsote, O. O. and Prucnal-Ogunsote, B. (2002b). Defining Climatic Zones for Architectural Design in Nigeria: A Systematic Delineation. Journal of Environmental Technology

Ogunsote, O. O. and Prucnal-Ogunsote, B. (2002c). Choice of a Thermal Index for Architectural Design with Climate in Nigeria. Habitat International – A Journal for the Study of Human Settlements, Pergamon Press, London.

John S. R. 2001 Courtyards: Aesthetic, Social, and Thermal Delight

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