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The recession in the late 1990s in Hong Kong has triggered many commercial building owners to cut operation and maintenance (O&M) cost via outsourcing. The purpose of this paper is to investigate the dominant expenditure on O&M service and examine the relation between extent of outsourcing and rental income of the buildings.

Experienced O&M practitioners were interviewed to collect both quantitative and qualitative data of the commercial buildings they looked after. The in‐house and outsourced O&M costs, air‐conditioning energy costs, rental incomes, and management and air‐conditioning fees for the buildings were analysed.

The total air‐conditioning O&M cost is the principal cost item, with the energy cost being the dominant element. The analysis reveals that the extent of outsourcing bore little correlation with the air‐conditioning O&M cost and the rental income.

Further work may take a similar approach to identify the extent and effect of outsourcing other kinds of services that underpin the core business of an organisation.

Varying the extent of outsourcing O&M service was found to be unpromising for enhancing rental performance or cutting O&M expenditure. This is an important point that the building managers should address when considering whether to go for outsourcing.

The findings imply that in the building O&M service industry, it would be more economical to outsource or undertake in‐house the vast majority of O&M work. The focus for cost minimization should be to improve building energy performance rather than reducing labour resources through outsourcing.

This study aims to examine the impact of local air pollution on the presence of central air conditioners in apartments in Lebanon.

This study applies a Probit model in a unique data set on apartments’ listings for sale in Lebanon collected by Marrouch and Sayour (2021). The data set includes information about air pollution concentrations, dwellings’ characteristics, geographic features and location characteristics.

This study finds that local air pollution positively and significantly affects the presence of central air conditioning in dwellings. The estimated increase in the probability of having central air conditioning for a one microgram per cubic meter increase in Particulate Matter 2.5 concentration is 6.4%.

The data set in this study is cross-sectional and thus does not capture variations over time for the examined variables.

The Probit regression approximates an equation that can predict the presence of central air conditioners in dwellings, which might be useful to policymakers.

The findings suggest that local pollution is a significant factor in household behavior in Lebanon.

This paper adds to the scant literature studying the effects of air pollution on the presence of central air conditioning in developing countries. To the best of the authors’ knowledge, this is the first paper to study the impact of air pollution on the presence of central air conditioning in the Middle East and North Africa Region.

The purpose of this paper is to describe and categorize calculation methods for conducting a complete air conditioning study. More specifically, this paper is a general review of cooling loads calculation methods, psychrometric calculations for installing a central air conditioning unit, ways of fan coil units connection and air duct calculation methods.

This paper was based on two pillars: a dissertation for an industrial facility and technical information found after methodical research.

After a brief reference of the calculation methods and the air conditioning systems installed in this industrial facility, this paper concludes with the most appropriate calculation methods for this industrial facility.

This study describes some calculation methods. Thus, future research could be addressed toward the analysis of more methods.

This paper includes implications for choosing the most appropriate calculation method according to the air conditioning system installed.

The originality of this paper lies in the fact that, except for the theoretical part, there are some examples taken from a case study, thus it can be used as a future guide for selecting methods and systems of industrial air conditioning.

The Heating, Ventilation and Air Conditioning (HVAC) system is a significant energy consumer in built environments, and the building energy consumption could be minimised by optimising HVAC controls. Hence, this paper aims to investigate the applicability of Variable Refrigerant Flow (VRF) air conditioning systems for optimising the indoor comfort of buildings in Sri Lanka.

To address the research aim, the quantitative approach following the survey research strategy was deployed. Data collected through questionnaires were analysed using descriptive statistical tools, including Mean Rating (MR), Relative Important Index (RII) and Standard Deviation (SD).

The findings revealed that VRF systems are popularly used in Sri Lankan apartment buildings. Furthermore, energy efficiency and comfort were recognised as the most significant top-ranked benefits, while ventilation issues and initial cost were recognised as significant challenges. Moreover, the allocation of trained technicians and provision of proper ventilation through a Dedicated Outdoor Air System (DOAS) were highlighted as applicable mitigation strategies for the identified challenges in VRFs.

The study recommends VRF systems as a suitable technology to ensure energy efficiency, reduce GHG emissions and achieve climate performance within the built environment. The opportunities for adopting VRF systems for developing countries could be explored based on the research findings. The identified challenges would assist the design engineers and facilities professionals to devise suitable strategies to mitigate issues of VRF systems in developing countries.

This research provides empirical proof of the energy efficiency and comfort aspects of VRFs. The study has explored and recommended VRF technology as a beneficial application to overcome the persistent energy crisis in developing countries.

Reviews development in air conditioning from cave dwellers to the mid 1970s in the UK. Presents an overview of common air conditioning systems, with their relative merits. Concludes that air conditioning gives increased comfort levels and efficiency. Argues that the design of systems should be user‐led, rather than technology‐driven.

Extreme temperature and humidity are major causes of errors in industrial precision and in dimensional measurement. In addition, hot and/or humid workplaces have adverse effects on humans which include reduced work time due to more frequent and longer breaks, reduced production rates, and increased error rates. Managers considering investments in air conditioning their manufacturing facilities must weigh many uncertain benefits against more certain costs. In this paper, we identify the benefits resulting from air conditioning manufacturing facilities and develop a Monte Carlo computer simulation model to evaluate investments in air conditioning. The model uses projected incremental cash flows to compute net present value and internal rate of return. Simulation is used to take into account the uncertainty associated with projecting the benefits of air conditioning, deal with possible correlation among some benefits of air conditioning, and sensitize decision makers to the range of possible outcomes. The proposed model is programmed into user‐friendly menu‐driven software which is tested on actual cases and is illustrated in this paper.

Air‐conditioning installations in buildings have been the focus of much criticism, with many commentators going so far as to propose a causal connection between sick buildings and air conditioning.

To examine the role of predicted mean vote (PMV) in air‐conditioned environments by conducting a thermal comfort study.

A formal statistical approach was adopted for the credibility of the study. Thermal measurements and questionnaire filling were carried out in commercial offices to collect the required data. Statistical analysis on the collected data and logical reasoning were then employed to derive the conclusions.

Provide an evidence to support PMV to be an appropriate thermal comfort index in air‐conditioned environments. Guarantee high productivity of occupants by using PMV in air‐conditioning control.

Future research work should be carried out to investigate any significant relationship between improvement in PMV and the profits gained by occupants inside an air‐conditioned space. With such relationship, it is possible to develop an intelligent air‐conditioning control to yield the most cost‐effective thermal environments for commercial offices.

Air‐conditioning engineers are highly recommended to employ PMV to assess the thermal comfort environment in air‐conditioned offices.

This paper highlights the importance aspect on choosing a thermal comfort index for comfort assessment in air‐conditioned offices. The index itself should not consider adaptive actions. Otherwise, the productivity of occupants would be severely deteriorated. It is well known that PMV is the thermal comfort index that can fulfill this requirement.

The aim of this paper is to discuss the impact of energy pricing on the implementation of low energy design principles in buildings.

The problem of rising air‐conditioning loads is not simply a matter of availability of power‐plants, but also one of the limited time periods over which demand peaks occur. The relationship between the feasibility of technical solutions and pricing policies of electricity is examined by means of a Greek case study, which is representative for Southern Europe.

The paper finds that in conventional air‐conditioning systems the impact of the peak cooling demand on the building's capital expenditure is low, compared to the operational expenses over the buildings' life cycle. In that sense the latter's reduction lies in the interest of the building's user, rather than the investor. If, however, changes in the pricing policies were to be adopted, annual operational expenses would more than double, making energy saving measures far more attractive. Such a scenario would reflect the Californian experience of 2000. However, it is misleading to think only of covering the demand, which is a product of the building's characteristics. Passive cooling techniques are very efficient in reducing the building's cooling load. The challenge lies in the integration of such techniques and solar cooling technologies, resulting thus in feasible solutions.

The evaluation of energy conservation techniques should be considered under the criterion of embodying the actual marginal operational cost of a utility to its rates, when providing peak loads.

The paper rejects the false dilemma of passive vs active energy conservation approaches, and demonstrates that on the long run the “business as usual” way of keeping electricity rates fairly flat is not only impracticable, but also destructive for energy conservation as such.

This article discusses the basics of computer‐room air conditioning, an important component of the special environment required by mainframe computers and many mini‐computers as well. Computer room air conditioners differ in some significant ways from “comfort” air‐conditioners, which are designed for the comfort of people rather than machines. These differences make it less than ideal to use air conditioning systems designed for human comfort for computer cooling. The author describes several different types of air‐conditioners, considerations related to the construction of a computer room, and factors that determine air‐conditioning requirements.