Air-conditioning Water System Research Articles

Energy Audits Reveal Significant Energy Savings Potential in India's Commercial Air-Conditioned Building Sector

The United States Agency for International Development (USAID) began its Energy Management Consultation and Training (EMCAT) project in India. The EMCAT project began in 1991 as a six-year (1991--1997) project to improve India`s technological and management capabilities for both the supply of energy and its efficient end use. The end-use component of EMCAT aims for efficient energy utilization by industries and other sectors such as the commercial sector. A specific task under the end-use component was to conduct energy surveys/audits in high energy-use sectors, such as air-conditioned (AC) buildings in the commercial sector, and to identify investment opportunities that could improve energy utilization. This article presents results of pre-investment surveys that were conducted at four commercial air-conditioned facilities in 1995. The four facilities included two luxury hotels in New Delhi, and one luxury hotel and a private hospital in Bombay. Energy conservation opportunities (ECOs) were explored in three major energy-using systems in these buildings: air-conditioning, lighting, and steam and domestic hot water systems.

Assessment of Costs and Benefits Associated with Resolution of Generic Safety Issue 143—Availability of Heating, Ventilation, and Air Conditioning and Chilled Water Systems

The Pacific Northwest Laboratory, under contract to the U.S. Nuclear Regulatory Commision, has conducted an assessment of the values (benefits) and impacts (costs) associated with potential resolutions to Generic Issue 143 - Availability of Heating, Ventilation, and Air Conditioning (HVAC) and Chilled Water Systems. The key objectives of the study were to (a) identify vulnerabilities related to failures of HVAC, chilled water, and room-cooling systems, (b) develop estimates of room heatup rates and safety-related equipment vulnerabilities following losses of HVAC/room-cooler systems, (c) develop estimates of the core damage frequencies and public risks associated with failures of these systems, (d) develop proposed resolution strategies to this generic issue, and (e) perform a value/impact analysis of the proposed resolutions. Detailed probabilistic risk assessments for four representative plants form the basis for the core damage frequency and public risk calculations. Internally initiated core damage sequences as well as external events were considered. Three proposed resolution strategies were developed for this safety issue, and it was determined that all three were not cost effective. Additional evaluations were performed to develop generic insights on potential design-related vulnerabilities potential high-frequency (>10 -4 /reaector-yr) accident sequences that involve failures of HVAC/room-cooling functions. It was concluded that, although high-frequency accident sequences may exist at some plants, these sequences are plant-specific in nature or have been resolved through hardware and/or operational changes. The plant-specific individual plant examinations appear to be an effective vehicle for identification and resolution of these plant-specific anomalies and hardware configurations

Measurement of IgG antibody and airborne antigen to control an industrial outbreak of hypersensitivity pneumonitis.

An outbreak of hypersensitivity pneumonitis in a textile plant was attributed on epidemiological grounds to a chilled water air-conditioning system where a slime was growing in the chilled water sump and on demister vanes. All of the patients and about 80% of their asymptomatic co-workers had strongly positive precipitin tests to extracts of the slime. An adaptation of a radioiodinated staphylococcal protein A solid-phase radioimmunoassay was applied to monitor antigen and specific antibody. To control the outbreak, a variety of cleaning and water treatment measures were taken between 1977 and 1979 to reduce the amount of antigen in the water and in the air. The amount of slime in the water was greatly reduced though the antigen content per gram of slime did not change. Airborne antigen in the affected work areas decreased progressively.

Cooling with geothermal heat

Fisher & Paykel Engineerign contracted to design and build a geothermally powered air conditioning and domestic hot water system for the new Tourist Hotel in Rotorua, New Zealand, involving about 2,000,000 BTU/h supplied by geothermal hot water. A buffer heat exchanger between the 300°F bore and 250°F clean hot water was used to serve absorption refrigeration as well as heating systems and domestic hot water calorifiers on the clean water side. Some comments are made on aspects of the design, control and general installation.