ISSN:0199-8595    

DOI:10.1080/01998595.1997.10530373

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

摘要:

ASHRAE Standard 62, in its current form, employs two procedures to provide acceptable indoor air quality (IAQ) in buildings. These are theVentilation RateandIndoor Air Quality (IAQ) Procedures. This standard further endeavors to achieve the necessary balance between IAQ and energy consumption by specifying minimum ventilation ratesandIAQ that will be acceptable to human occupants.

ISSN:0199-8595    

DOI:10.1080/01998595.1997.10530374

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

摘要:

The proposed ASHRAE/IES Standard 90.1-1989R contains updated requirements for pipe insulation thicknesses developed on the basis of technical and economic principles. These requirements were determined based on computer simulations of the annual energy loss through the insulation, first cost assumptions for the insulation, and economic assumptions of discount rate and energy escalation rate. In later work, the same tools were used to analyze the sensitivity of the cost-effective insulation level for piping insulation to variations in operating hours, ambient temperature, fluid temperature, and economic assumptions. These analyses were carried out using cost data for pipe insulation averaged across several sources. The results of the sensitivity study showed that system operating hours is a critical parameter in determining the cost-effective pipe insulation thicknesses. Although there is a lack of reliable sources of typical operating hour data for heating systems, anecdotal information suggests that while most smaller building-level systems are operated only during a heating season, many site-wide steam and hot water heating systems are operated year round and insulation levels on these systems should reflect both the pipe size and the different operating schedules. In addition, the analysis showed that due to differences in private and federal sector economics, the cost-effective pipe insulation levels appropriate for the private sector are often substantially different from those that are appropriate for the federal sector.

ISSN:0199-8595    

DOI:10.1080/01998595.1997.10530375

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

摘要:

Refrigerant subcooling is a demonstrated and reliable way of increasing cooling capacity and system efficiency for conventional air-conditioning and refrigeration systems. There are several proven refrigerant subcooling devices available on the market; but this article will focus on a relatively new implementation which modifies a standard direct-expansion, vapor-compression refrigerant system through the addition of a liquid line heat exchanger downstream from the condenser and a minicooling tower to reject the heat from the heat exchanger. Because of additional first cost (heat exchanger and minicooling tower), it is economical only with certain applications.

ISSN:0199-8595    

DOI:10.1080/01998595.1997.10530376

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor