Effective Ventilation Parameters and Thermal Comfort Study of Air-conditioned Offices

Roonak Daghigh,Kamaruzzaman Sopian

doi:10.3844/ajas.2009.943.951

Roonak Daghigh, Kamaruzzaman Sopian

Open Access

https://doi.org/10.3844/ajas.2009.943.951

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Abstract

The study presents objective and subjective studies of thermal comfort levels and ventilation characteristics of two air-conditioned postgraduate study offices. The observations were performed at the offices of Department of Electrical and Electronic Engineering, in University Putra Malaysia. Thermal comfort variables were measured while the students answered a survey on their sensation of the indoor climate. Concurrently, tracer gas analysis, based on concentration decay method, is employed to determine air exchange rate, age of air and air exchange effectiveness. During the air conditioner is working, the study offices had not conditions within the comfort zone, of ASHRAE standard 55 causing occupants to report cold thermal sensations and the objective data analysis showed that the offices were uncomfortable. The thermal neutralities were significantly higher that proposed by ASHRAE Standard 55:1992. The monitored air exchange rates are indicated that the provisions of outside air for ventilation based on design occupancy are adequate for these two study offices. In addition, questionnaires were completed by the students in order to provide a subjective assessment of thermal comfort and indoor air quality. Finally, the outcomes of over 30 surveys for each office responses to the thermal comfort questions are presented and discussed.

Highlights

Malaysia is located in the tropical region with a hot and humid climate where a large number of the buildings served by air-conditioning systems
These analysis's resulted from the measurement in the middle of October, 2006 from 9.00 a.m. to 17.00 p.m. when air-conditioner was on all the time, These results show that more than half of the occupants felt thermally uncomfortable in the office space 1 during sedentary activities at that period of time with an average temperature of 21.5oC and relative humidity of 53%
It was observed that the state of temperature for offices are far from the thermal comfort of 26°C from the guideline given by Malaysian Energy Efficient Guideline (MEEG), hardly to achieve the thermal comfort during office hours according to MEEG

Summary

Introduction

Malaysia is located in the tropical region with a hot and humid climate where a large number of the buildings served by air-conditioning systems. Over the past three decades, Malaysia has been experiencing fast economic and social transformation as well as rapid urban growth. High and medium density housing will be widespread given the high cost of land and constructions on urban space to cope with housing demand. Malaysia’s energy consumption has increased, where the corresponding energy demand would significantly increase in the coming years. Primary concern should be given to making sure that the people inside are happy and comfortable to stay-they are not too hot or too cold .Through the knowledge of thermal comfort behavior of human and energy utilization behavior of buildings, the best strategy can be adopted[1]

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