March_1967 — Page 27

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BUILDING FOR NIGHT COMFORT IN HUMID CLIMATES

ITH our concern for cost, struc- tural soundness, and aesthetic appearance, our pre-occupation with functional efficiency and climatic per- formance of buildings during the day- time, we neglect a most important as- pect of building design night com- fort. The night environment gener- ally, is an aspect of design too often disregarded in buildings such houses, hospitals, and hotels: places where people have to sleep.

as

The environment relating to hu- man comfort during sleep, from say. 10.00 p.m. to 6.00 a.m., is vitally im- portant, for human beings must spent about one-third of their lifespan in this condition.

Certainly, buildings such as those mentioned will contain bedrooms, but how much attention is really given to the need for an environment which is suitable for sleeping? This sphere of building knowledge has not been greatly studied by architects, and is not particularly well documented, es- relation to pecially in

warm and humid tropical climates.

Area for Research

The subject deserves more atten- tion. For example, more people will be occupying a house at night than during the day. Now, because of this greater night-time occupancy, there is a real need for a comprehen- sive study of the conditions for a good night's sleep and rest in the humid tropics, especially in relation to the requirements of shelter from clima- tic and other environmental factors.

While the subjective aspects of thermal discomfort at night are well known, and correct design procedures and technical means are now avail- able within a reasonable budget, for rectifying, or at least alleviating the worst conditions, nevertheless much further thought is required. Only some of the facts are known at pre- sent, and we do not know enough about the human factors affecting thermal design of buildings for night- time occupation in tropical regions.

To base our current approach to the internal thermal environments of buildings on the criteria for daytime use only, may perhaps be a serious error of judgement. The daytime criteria of sunlight,, daylight, glare. solar radiation, ventilation, etc.. are important, and must still be taken

*This article is adapted from a paper by Mr. J. D. Kendrick of the University of Adelaide

Far East Architect & Builder March, 1967

by J.D. Kendrick

fully into account. However, it may be that the really critical factor in de- sign for thermal comfort is the pre- ferred thermal environment for rest- ful sleep at night. At the moment of course, we do not know, because the necessary research has not been com- pleted. Some data now available sug- gest that there may be a difference in the thermal requirements of human beings by day and by night.

The common phenomenon of dis- turbed sleep in warm and humid en-

*

*

vironments has been high-lighted by MacPherson and Muncey) in a thermal comfort survey undertaken from November 1960 to February 1961, at Batchelor (Lat. 13°S). just south of Darwin in the Northern Ter- ritory of Australia.

Disturbed Sleep

The relevance of this survey to warm and humid tropical countries throughout the world, is indicated by the climate of Batchelor, which is

TABLE I

Daytime thermal comfort in humid tropics*

THERMAL COMFORT DATA

Effective § Temperature

PLACE

RACE

Dry Bulb Temperature

European

Range:

Range:

76°F - 85°F

73°F - 78°F

SINGAPORE (Ref. 7)

Corrected $$ Effective Temperature

Upper Limit

78*F

MALAYA

(Ref. 8)

Malay Chinese

Range:

Range:

80°F - 86°F

77°F-81°F

Upper Limit

79°F

JAVA

Range:

Range:

Indonesian

(Ref. 9)

71°F - 85°F

68°F - 79°F

SHIP IN TROPICS

(Ref. 10)

NEW GUINEA

(Ref. 5)

Range:

Range:

Indian

75°F - 84°F

72°F - 79°F

European

Optimum 78°F

NEW GUINEA

(Ref. 5)

Indigenes

Optimum 79°F

CALCUTTA

(Ref. 11)

Range:

Indian

74°F - 83°F Optimum 78.5°F

Range:

68°F-76.5°F Optimum 72.5°F

Upper Limit

77°F

(Ref. 4)

Nigerian

Optimum 75°F Upper Limit

84°F

Optimum 69°F Upper Limit

76°F

Upper Limit

77°F

KANO

Comfort Zones.

Based on tabulated data in: W. V. MACFARLANE: Thermal Architectural Science Review, No. 1958, 1, No. 1, p. 1-14; with additions.

§ Effective Temperature is an Index of Comfort obtained by combining the effects

of air temperature, humidity and air movement.

§§ Corrected Effective Temperature is an Index of Comfort similar to Effective Temperature, but also including the effects of radiation (as measured with globe thermometer).

Note: Climates of Singapore, Malaya, Indonesia and New Guinea, (all excluding mountain areas), are classified as Rainy Tropical (Af) Climate, while Calcutta and Kano are classified as Wet and Dry Tropical (Aw) Climate, i.e. similar to Batchelor (see text), according to Koppen-Geiger (Ref. 2).

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