Domestic and commercial air conditioning use in northern Cyprus: A study on occupant use patterns

This paper was principally aimed at identifying the occupant air conditioning use patterns in northern Cyprus under real "in-use" conditions. Consequently, 2 residential buildings and 2 commercial buildings were monitored continuously for 1 week periods. The temperature and relative humidity in the commercial buildings and in the main living room, the main bedroom and in an unconditioned space in the dwellings was monitored by using portable battery powered dataloggers. The electricity use of the air conditioners was monitored by connecting a current clamp directly onto the live cable of the unit. The external microclimate conditions in Nicosia and Kyrenia were also monitored simultaneously by using Stevenson Screens. The main conclusions of the study are summarized below: The air conditioning use in the monitored commercial buildings was dictated by the opening hours of the buildings where the average day temperatures in each city were 36.4 C (standard deviation of 1.3 C) and 32.8 C (standard deviation of 1.2 C), which were well above the occupant comfort limits The orientation of the commercial buildings had an impact on the cooling load where for the site that had high level windows facing east, the peak internal temperature was experienced at the beginning of the cooling period It was calculated that approximately 60% of the total monthly July bill of the commercial buildings was due to air conditioning use The duration of air conditioning use in bedrooms (between 7-10 hours) was higher than the duration of air conditioning use in living rooms (between 4-6 hours), however due to the larger living rooms and the use of higher capacity air conditioners in the living rooms, the electricity consumption of the air conditioners in the living rooms was higher than the electricity consumption of the units used in bedrooms In line with the simulation study done by Lin and Deng, the peak temperature in bedrooms was observed to be at the beginning of the cooling period and as a result the occupants were turning on their air conditioning units and leaving them on until they wake up. The same use pattern was observed by Pathan et al. (2007) in a study in southeast England The average switch-on temperature was identified as 29.6 C, considerably higher than the UK switch-on temperature of 24.2 C, implying that factors such as the clothing level or acclimatization of the occupants are important which should also be considered Employing a "mixed-mode" approach at night in bedrooms was not very effective because of the high external night-time relative humidity even though the external night temperatures were suitable. One solar cooling technology that can specifically address this issue is the open desiccant cycle which can be used to dehumidify the incoming air The internal temperatures in residential buildings were lower than the external at temperatures above 29.7 C. This temperature can be used to estimate the energy consumption of dwellings in northern Cyprus as it enables the prediction of the level of overheating by only using the external temperature. The UK average external temperature above which the internal temperatures were lower than the external was estimated as 25.0 C by Young et al. (2007) The base temperatures to estimate the cooling degree days were calculated as 21.0 C for day-use and 23.2 C for night-use. These temperatures were comparable with the base temperature of 22 C used by Zachariadis and Pashourtidou (2006) in order to analyze the effect of weather on the electricity consumption The study has no statistical significance because of the very small sample size which limits the generalization of the results to the whole population. However, the study provides valuable information regarding the air conditioning use pattern in the specific case studies. The literature on occupant air conditioning use pattern is rare and in the case of northern Cyprus no such studies exist, therefore the study provides valuable preliminary information. This study indicates that to understand and approach the potential impact of increasing air conditioning demand on electricity network, environment and the occupant comfort, it will be necessary to monitor the air conditioning use under real "in-use" conditions which will provide statistical data that can be fed into simulation software for more accurate prediction of future trends. (Abstract shortened by UMI.