KOSEN 한인과학기술자네트워크

아래의 자료는 산업기술정보원(http://www.kiniti.re.kr)을 통해 검색된 자료입니다. 참고하시기 바랍니다. 웹을 통해 원문신청이 가능합니다. * MECHANISM OF OIL-R12 REACTIONS - THE ROLE OF IRON CATALYST IN GLASS SEALED TUBES, Sanvordenker, K. S., ASHRAE Transactions: Technical Papers presented at the 1985 Winter Meeting. ASHRAE Transactions v 91 n pt 1A, p 356-369, 1985, 2 Abstract : The chemical stability of refrigeration oils is commonly determined by tests in glass sealed tubes containing R12, oil, and steel. This paper presents the details of the hitherto sketchy chemistry of sealed tube tests. Iron has been found to be solubilized by oil and transported to the glass surface, where the iron-oil molecule, along with the refrigerant, reacts with the glass to form boron-hydrogen and silicon-fluorine compounds, while precipitating out the solubilized iron. Based on gas analysis by infrared, a criterion to identify the entry of glass in sealed tube reactions is defined. * Investigation of the mechanism of the R12-oil-steel reaction , Factor, A.; Miranda, P.M.;, Wear v 150 n 1-2, p 41-58, 1991, Abstract : Past work has shown that the chemical stability of hydrocarbon lubricating oils used in closed refrigeration compressor systems containing the refrigerant CCl$-2$/F$-2$/ (R12) is diminished by a chemical interaction between the oil, the R12 and the steel surfaces present in the compressor. The present study was undertaken to better understand and control this negative interaction. Using three-day 200$DGR@C sealed tube reactions with R12 and steel to simulate the conditions existing in an operating refrigeration compressor, the mechanism of the R12-oil-steel degradation reaction was explored by testing the effect of the presence of various probe and model compounds. The results indicate that, except perhaps for the formation of FeCl$-3$/ and some CHClF$-2$/ (R22), free radical reactions do not appear to play a major role in the oil-R12-steel reaction. The preponderance of the data indicates that Friedel-Crafts reactions, especially alkylation reactions, play a key role in the oil-R12-steel degradation chemistry. >저는 현재 R12, R22, 134a라는 냉매에 대해 테스트를 실시해야 합니다. >냉매의 화학적 안정성 테스트를 위한 표준화된 장비(ANSI/ASHRAE 97)에 관한자료를 수집 중이죠. 사용해보신이나 판매 업체 등도 알고 싶습니다. 기타 관련전문가도 함께 알수 있었으면 좋겠네요. > >Key Word : R12, R22, Refrigerant, Sealed Glass tube.

>아래의 자료는 산업기술정보원(http://www.kiniti.re.kr)을 통해 검색된 자료입니다. 참고하시기 바랍니다. 웹을 통해 원문신청이 가능합니다. > >* MECHANISM OF OIL-R12 REACTIONS - THE ROLE OF IRON CATALYST IN GLASS SEALED TUBES, Sanvordenker, K. S., ASHRAE Transactions: Technical Papers presented at the 1985 Winter Meeting. ASHRAE Transactions v 91 n pt 1A, p 356-369, 1985, 2 >Abstract : The chemical stability of refrigeration oils is commonly determined by tests in glass sealed tubes containing R12, oil, and steel. This paper presents the details of the hitherto sketchy chemistry of sealed tube tests. Iron has been found to be solubilized by oil and transported to the glass surface, where the iron-oil molecule, along with the refrigerant, reacts with the glass to form boron-hydrogen and silicon-fluorine compounds, while precipitating out the solubilized iron. Based on gas analysis by infrared, a criterion to identify the entry of glass in sealed tube reactions is defined. > >* Investigation of the mechanism of the R12-oil-steel reaction , Factor, A.; Miranda, P.M.;, Wear v 150 n 1-2, p 41-58, 1991, >Abstract : Past work has shown that the chemical stability of hydrocarbon lubricating oils used in closed refrigeration compressor systems containing the refrigerant CCl$-2$/F$-2$/ (R12) is diminished by a chemical interaction between the oil, the R12 and the steel surfaces present in the compressor. The present study was undertaken to better understand and control this negative interaction. Using three-day 200$DGR@C sealed tube reactions with R12 and steel to simulate the conditions existing in an operating refrigeration compressor, the mechanism of the R12-oil-steel degradation reaction was explored by testing the effect of the presence of various probe and model compounds. The results indicate that, except perhaps for the formation of FeCl$-3$/ and some CHClF$-2$/ (R22), free radical reactions do not appear to play a major role in the oil-R12-steel reaction. The preponderance of the data indicates that Friedel-Crafts reactions, especially alkylation reactions, play a key role in the oil-R12-steel degradation chemistry. > > > >>저는 현재 R12, R22, 134a라는 냉매에 대해 테스트를 실시해야 합니다. >>냉매의 화학적 안정성 테스트를 위한 표준화된 장비(ANSI/ASHRAE 97)에 관한자료를 수집 중이죠. 사용해보신이나 판매 업체 등도 알고 싶습니다. 기타 관련전문가도 함께 알수 있었으면 좋겠네요. >> >>Key Word : R12, R22, Refrigerant, Sealed Glass tube. ---------------------------------------------------------------- 1. Technique for evaluating steady-state conditions in flat-plate solar collector testing Lindley, M.R. (Univ of Kentucky) Parker, B.F. | Colliver, D.G. | Murphy, W.E. Source: ASHRAE Transactions v 99 pt 1 Jan 23-27 1993 1993 Publ by ASHRAE p 35-42 0001-2505 Abstract: Testing air- and liquid-filled solar collectors according to ANSI/ASHRAE 93-1986 (ASHRAE 1986) has proved difficult in much of the world due to the strict steady-state requirements set forth in the standard. This paper presents a method to quantify the level of quasi-steady state using the first-order time response of the collector to weigh changes in energy collected and inlet temperature. Using existing test data from 16 clear days, the method produced thermal performance curves that were statistically indeterminate from curves produced using a modified version of ANSI/ASHRAE 93-1986. Relaxing the wind and solar radiation restrictions was necessary to obtain an ANSI/ASHRAE 93-1986 plot. The method presented in this paper should significantly reduce the time required and, therefore, the costs of conducting steady-state thermal performance tests for both air- and liquid-based solar collectors. In English Refs EI93081047297 2. Dental ventilation theory and applications Ninomura, Paul T. (U.S. Public Health Service) Byrns, George Source: ASHRAE Journal v 40 n 2 Feb 1998 ASHRAE p 48-50, 52 0001-2491 Abstract: Guidance on ventilation design for dental offices is limited. Even the ASHRAE does not offer guidance on ventilation for dental spaces. Neither ANSI/ASHRAE Standard 62-1989: Ventilation for Acceptable Indoor Air Quality nor the ASHRAE Handbook-HVAC Applications address this space utilization. The lack of a national design standard leads to the presumption that many dental offices have ventilation designs suited for nominal office usage. This may contribute to marginal indoor air quality in the dental setting. The ventilation system of two federal agencies are examined along with the potential exposure to airborne contaminants at levels of concern of the dental professionals as well as the patients. In English 21 Refs. EI98034097142 3. ASHRAE Standard: Addenda to ANSI/ASHRAE 90.2-1993. Energy efficient design of new low-rise residential buildings Source: ASHRAE Standard 90.2-1993 Aug 1997 2p 1041-2336 Abstract: In English EI97113934364 4. ASHRAE Standard: Addenda to ANSI/ASHRAE 34-1992. Number designation and safety classification of refrigerants Source: ASHRAE Standard 34-1992 Aug 1997 2p 1041-2336 Abstract: In English EI97113934363 5. Using the ASHRAE 110 test as a TQM tool to improve laboratory fume hood performance Hitchings, Dale T. (Hitchings Associates) Maupins, Karen Source: ASHRAE Transactions v 103 n pt 2 Jun 28-Jul 2 1997 1997 Sponsored by: ASHRAE ASHRAE p 851-862 0001-2505 Abstract: ANSI/ASHRAE 110-1995, Method of Testing Performance of Laboratory Fume Hoods (ASHRAE 1995) yields quantitative data about fume hood containment and can be used in a classical total quality management (TQM) approach to process improvement. This involves measuring process indicators, analyzing probable causes of poor performance, implementing changes to the process, and again measuring the indicators to determine the efficacy of the changes implemented. This paper outlines the ASHRAE 110 method and how it was used to evaluate the containment performance of fume hoods in the quality control laboratory of a pharmaceutical manufacturing plant, the techniques implemented to improve performance, and the final results. An average reduction of 99.5% in ASHRAE 110 tracer gas control levels was realized. These ASHRAE 110 tests, combined with several thousand others, reveal that 30% to 50% of the hoods tested that meet industry standard face velocity specifications have leakage rates that exceed industry guidelines. In English 9 Refs. EI98034115440 6. Proceedings of the 1995 ASHRAE Annual Meeting Source: ASHRAE Transactions 101 Pt 2 Jun 24-28 1995 1995 ASHRAE 1445p 0001-2505 Abstract: The proceedings contains 126 papers. Topics discussed include heat transfer, refrigeration, adsorption, air conditioning, refrigerants, energy conservation, commercial kitchen ventilation, air control methods for ANSI/ASHRAE standards, control systems for HVAC systems, radiant cooling, thermal measurements and modeling, Atrium building design, underfloor air distribution, refrigeration lubricant technology, heat recovery ventilators, durability testing of fenestration systems, fluid flow, design and installation of gas heat pump systems, air quality in animal facilities, developments in domestic refrigerator and freezer designs, two phase flow, thermal energy storage, and engine driven heating and cooling systems. In English EI96033103517 7. Field study of occupant comfort and office thermal environments in a hot, arid climate Cena, Krzysztof (Murdoch Univ) de Dear, Richard J. Source: ASHRAE Transactions 105 (PART 2) Jun 18-Jun 23 1999 1999 ASHRAE p 204-217 0001-2505 Abstract: This paper presents the main findings of ASHRAE research project RP-921 a field study of occupant comfort and office thermal environment in 22 air-conditioned office buildings in Kalgoorlie-Boulder, Western Australia, a location characterized by a hot and arid climate. A total of 935 subjects provided 1,229 sets of data for winter and summer, each accompanied by a full set of indoor climatic measurements with laboratory-grade instrumentation. Clothing insulation estimates for seated subjects (0.5 clo in summer and 0.7 in winter) were supplemented by the incremental effect of chairs (0.15 clo). Thermal neutrality according to responses on the ASHRAE seven-point sensation scale, occurred at 20.3 °C in winter and at 23.3 °C in summer. Preferred temperature, defined as a minimum of subjects requesting temperature change was 22.2 °C for both seasons. Nearly 65% of the indoor measurements fell within the ANSI/ASHRAE Standard 55a-1992 summer comfort zone and 85% in the winter. Over 85% of the occupants considered their thermal conditions acceptable. Subjects who expressed a below-average level of job satisfaction on a 15-question index were 50% more likely to express dissatisfaction with their thermal environment than subjects with above-average job satisfaction. In English 26 Refs. 8. Field testing of advanced ventilation controls for variable air volume systems Mumma, Stanley A. (Pennsylvania State Univ) Ke, Yu-Pei Source: Environment International v 24 n 4 May 1998 Elsevier Sci Ltd p 439-450 0160-4120 Abstract: Results from the experimental phase of a larger research project are presented for three promising ventilation controls capable of meeting the ventilation requirements of ANSI/ASHRAE Standard 62-1989 (ASHRAE 1989) with low energy use. Each control dynamically adjusted the outdoor air (OA) requirement based upon occupancy and measured building zone loads. Credit for unvitiated air from over-ventilated spaces was also taken in each control. Controls 2 and 3 used primary airflow rate as an optimization variable to decrease the required OA flow rate, thus reducing the energy needed to condition OA. The supply air temperature in control 2 was a constant, but was an additional optimization variable in control 3. The three ventilation controls were achieved by the simulation/optimization algorithms resident in a stand-alone personal computer (PC) on site. A total of 24 days of performance data were collected. Typical day data sets for each control are presented in some detail. The objective of the experimental phase was to verify the reliability of the simulation/optimization algorithms resident in the on-site PC. That objective was met for each of the three controls since excellent agreement was found between the measured data and the control algorithm predictions. In English 9 Refs. EI98114436882 9. Classroom indoor air quality vs. ventilation rate Downing, C.C. (Georgia Tech Research Inst) Bayer, C.W. Source: ASHRAE Transactions v 99 pt 2 Jun 27-30 1993 1993 Publ by ASHRAE p 1099-1103 0001-2505 Abstract: The heating, ventilating, and air-conditioning (HVAC) system of an existing elementary school classroom building located in Augusta, Georgia, was renovated to upgrade the outdoor air ventilation rate and to provide better humidity control. The renovation was the result of numerous indoor air quality complaints and the persistent presence of mold and mildew on interior surfaces. The ventilation rate was increased to a constant 15 cfm per student as recommended in ANSI/ASHRAE 62-1989 (ASHRAE 1989). Previous to the renovation, outdoor air was provided by intermittent operation of rooftop HVAC units at approximately 5 cfm per student. A total energy recovery wheel system was employed to supply the outdoor air and to control relative humidity between 30% and 60%. In order to demonstrate the effectiveness of the system, indoor air quality (IAQ) measurements including volatile organics, formaldehyde, carbon dioxide, temperature, and relative humidity were monitored throughout the day at both the old and new operating conditions. The results of these measurements provide justification for ASHRAE Standard 62-1989 and indicate the need for better humidity control in classroom facilities. In English 9 Refs EI94031232814 10. Performance evaluation of a heat pump system with near azeotropic refrigerant mixtures of R-32, R-125, and R-134a Goswami, D.Y. (Univ of Florida) Mathur, G.D. | Gupta, S. | Kuo, W. Source: American Society of Mechanical Engineers, Advanced Energy Systems Division (Publication) AES v 36 Nov 17-22 1996 1996 Sponsored by: ASME ASME p 69-74 Abstract: Tests were conducted at the University of Florida's Solar Energy and Energy Conversion Laboratory (SEECL) for evaluation of the performance of a residential 3 ton split unitary heat pump system with near azeotropic refrigerant mixture. The performance of the heat pump system was tested in accordance with the ARI Standard 210/240 (ARI 1989) and ANSI/ASHRAE-37-1988 for testing unitary equipment. ASHRAE's 'Air Enthalpy Method' was used to determine the performance of heat pump system and ASHRAE's condition 'A' [Outside 95°F DBT/75°F WBT; Inside 80°F DBT/67°F WBT] was maintained for the tests. Initial base line tests were conducted on the system with R-22 with an orifice for expansion. The system was then tested with near azeotropic refrigerant mixture of R-32 (30%)/R-125(10%)/R-134a(60%). The subcooling and superheat at ASHRAE condition 'A' were matched with the base case with R-22. The performance of the system with the refrigerant mixtures of R-32/R-125/R-134a was lower by approximately 4-5% in comparison to the base case with R-22. In English 7 Refs. 11. Experimental investigation of the effect on the performance of an air-conditioning system Goswami, D.Y. (Univ of Florida) Mathur, G.D. | Gupta, S. | Stoff, L. | Colacino, F. Source: Proceedings of the Intersociety Energy Conversion Engineering Conference 3 Aug 11-16 1996 1996 Sponsored by: IEEE IEEE p 2021-2026 0146-955X Abstract: Tests were conducted at the University of Florida's Solar Energy and Energy Conversion Laboratory (SEECL) to determine the effect of the moisture on the performance of a 3 ton residential heat pump system with R-22 as the working fluid. The performance of the heat pump system was tested in accordance with the ARI Standard 210/240 (ARI 1989) and ANSI/ASHRAE-37-1988 for testing unitary equipment. ASHRAE's `Air Enthalpy Method' was used to determine the performance of heat pump system and ASHRAE's condition `A' [Outside 95 °F DBT/75 °F WBT; Inside 80 °F DBT/67 °F WBT] was maintained for the tests. The experimental data reveals that moisture levels of approximately 700 ppm in the refrigerant can decrease the system performance by 10-15%. Approximately 50-60% of the moisture injected into the system remains in the refrigerant and the rest mixes with the compressor oil. Hence, it is possible that over a period of time the moisture in the compressor oil may breakdown at the prevailing temperatures and pressures to form acids which may result in catastrophic failure. In English Refs. EI96113427628 12. Air-cleaning strategies for equivalent indoor air quality Yu, H.H.S. (Farr Co) Raber, R.R. Source: ASHRAE Transactions v 98 pt 1 Jan 25-29 1992 1992 Publ by ASHRAE p 173-181 0001-2505 Abstract: ANSI/ASHRAE 62-89, Ventilation for Acceptable Indoor Air Quality (ASHRAE 1989), provides guidelines for achieving acceptable indoor air quality in occupied spaces by either of two methods: a Ventilation Rate Procedure and an Indoor Air Quality procedure. The Ventilation Rate Procedure prescribes ventilation rates (in Table 2 of the standard) that it is assumed will provide adequate indoor air quality when 100% outdoor air is used. This 100% outdoor air valve is also the minimum supply airflow per person. The amount of outdoor air in this minimum supply airflow may be reduced below 100% by recirculating adequately cleaned return air if the Indoor Air Quality Procedure is used. The Indoor Air Quality Procedure does not set outdoor air ventilation rates but employs both qualitative and subjective air quality evaluation. By mathematical analysis, this paper helps implement the Indoor Air Quality Procedure by determining what filter efficiencies are needed (particulate and gas) to account for source capture efficiency, reduced outdoor airflow, and poor ventilation effectiveness, all under VAV conditions. In English EI93071029977 13. Laboratory fume hood and exhaust fan penthouse exposure risk analysis using the ANSI/ASHRAE 110-1995 and other tracer gas methods Hitchings, Dale T. (Hitchings Associates) Source: ASHRAE Transactions v 103 n pt 2 Jun 28-Jul 2 1997 1997 Sponsored by: ASHRAE ASHRAE p 863-872 0001-2505 Abstract: The use of the laboratory fume hood as the primary containment device in the laboratory has been a standard practice for almost half a century. Quantitative testing of the performance of these devices, however, is a more recent discipline. The use of the ANSI/ASHRAE 110-1995, Method of Testing Performance of Laboratory Fume Hoods (ASHRAE 1995) is becoming a standard specification in the purchase of new fume hoods, the commissioning of new laboratory facilities, and benchmarking fume hoods in existing facilities. Part I of this paper proposes a risk analysis method by which worker exposure to hazardous substances used in laboratory fume hoods may be estimated using results from the ASHRAE 110 method and formulae to extrapolate this information into potential exposure scenarios. Contaminated air leaking from hazardous exhaust systems located inside buildings or fan penthouses can pose a health risk to building occupants and maintenance workers. This is why prudent design practices for new buildings recommend that the fans powering these systems be located outside. In existing buildings with fans located inside or where a penthouse is required for weather conditions, however, it may be necessary to estimate potential worker exposure to hazardous agents released by these systems into the worker's environment. Part II of this paper proposes a method and formulate by which this risk may be evaluated based on measurement of leakage using a tracer gas release, capture, and detection method. In English 12 Refs. EI98034115441 14. Building pressure controls to comply with the Americans with disabilities act and ASHRAE standard 62-1989 Avery, Gil (Kele & Associates) Source: ASHRAE Transactions 101 Pt 2 Jun 24-28 1995 1995 ASHRAE p 619-624 0001-2505 Abstract: The Americans with Disabilities Act is a Civil Rights Law that, in part, defines the maximum allowable force required to open doors. This section of the law affects not only the door-closer manufacturers, but the HVAC design engineers since the door-opening force relates to the pressure in the building. The force required to open nonfire-rated interior doors is 5.0 lbs. The exterior-door limit is 'Reserved' (an undefined term), although the 8.5 lbs maximum force recommended in ANSI Standard A117.1-1986 is commonly used. The author uses the retrofit of the HVAC system in a midwest office building to show how the lobby pressure was brought under control to comply with this act and what changes were made to the equipment to meet the ventilation requirements of ASHRAE Standard 62-1989. In English EI96033102747 15. Number designation and safety classification of refrigerants Anon Source: Ashrae Standard 34a-34j 1994 ASHRAE p 1-5 1041-2336 Abstract: The modifications made on Tables 1 and 2 of ANSI/ASHRAE (American National Standards Institute/American Society of Heating Refrigerating and Air Conditioning Engineers, Inc.) 34-1992, including the addition of safety classifications for refrigerants R-124, R-125, R-218, and R-32, and the addition of refrigerant number designations and safety classifications for several blends, are presented. Modifications made on the chemical names in order to make them consistent with the International Union of Pure and Applied Chemistry (IUPAC) nomenclature convention are also presented. In English EI95022600011 16. System selection Wheeler, A.E. Source: ASHRAE Journal n Suppl Jun 1998 ASHRAE p 12-16 0001-2491 Abstract: A recent study of the indoor environment in 25 urban K-12 schools located in the eastern United States revealed the most common complaint was poor temperature control, during both warm and cold weather. Paradoxically, more often than not, the 'too warm' response came during the heating season and the 'too cold' response during the cooling season. Complaints relating to the quality of indoor air were surprisingly few even where the outdoor ventilation rates were substantially lower than recommended by ANSI/ASHRAE Standard 62-1989, Ventilation for Acceptable Indoor Air Quality. In English 8 Refs. EI98074278844 17. Application of CO2-based demand-controlled ventilation using ASHRAE Standard 62: optimizing energy use and ventilation Schell, M.B. (Engelhard Sensor Technologies) Turner, S.C. | Shim, R.O. Source: ASHRAE Transactions v 104 n 2 Jun 21-24 1998 1998 ASHRAE p 1213-1225 0001-2505 Abstract: CO2-based demand-controlled ventilation (DCV), when properly applied in spaces where occupancies vary below design occupancy, can reduce unnecessary overventilation while implementing target per-person ventilation rates. A recent interpretation of ANSI/ASHRAE Standard 62-1989, Interpretation IC 62-1989-27, has affirmed that carbon dioxide (CO2)-based demand-controlled ventilation (DCV) systems can use CO2 as an occupancy indicator to modulate ventilation below the maximum total outdoor air intake rate while still maintaining the required ventilation rate per person, provided that certain conditions are met. This paper, co-written by the author of the interpretation, provides guidelines on the application of CO2-based DCV. In addition, a method is presented that allows reasonable estimates of the actual ventilation rate per person being effectively delivered to the space, based on comparing predicted CO2 ventilation levels with CO2 levels logged in an occupied space. Finally, a model is presented to evaluate various CO2-based DCV strategies to predict their delivery of target per-person ventilation rates within the lag times required by the standard. In English 10 Refs. EI99024566784 18. Toward a simplified design method for determining the air change effectiveness Rock, Brian A. (Univ of Kansas) Brandemuehl, Michael J. | Anderson, Ren S. Source: ASHRAE Transactions 1 Jan 29-Feb 1 1995 1995 ASHRAE p 217-227 0001-2505 Abstract: This paper describes progress in developing practical air change effectiveness modeling techniques for the design and analysis of air diffusion in occupied rooms. The ultimate goal of this continuing work is to develop a simple and reliable method for determining heating, ventilating, and air-conditioning (HVAC) system compliance with ventilation standards. In the current work, simplified two-region models of rooms are used with six occupancy patterns to find the air change effectiveness. A new measure, the apparent ACH effectiveness, yields the relative ventilation performance of an air diffusion system. This measure can be used for the prediction or evaluation of outside air delivery to the occupied part of a room. The required outside air can be greater or less than that specified by ventilation standards such as ANSI/ASHRAE Standard 62-1989 due to poor or effective air distribution. In English Refs. EI95082812374 19. Development of an emissions test procedure for unitary combustion engine-driven heat pumps Chapman, Kirby S. (Kansas State Univ) Gorder, Peter J. | Wagner, Edward Source: ASHRAE Transactions v 104 n Pt 1B Jan 18-21 1998 1998 ASHRAE p 1463-1470 0001-2505 Abstract: The objective of this paper is to present the results of a review of several emissions testing standards that could potentially be used to standardize emissions measurements from unitary combustion engine-driven heat pumps (UCEDHPs). Existing emissions standards generally characterize emissions from stand-alone engines and do not apply to complete appliances. Consequently, portions of standards were selected as add-ons to the existing UCEDHP performance standard, ANSI Z21.40.4, Performance Testing and Rating of Gas-Fired, Air-Conditioning and Heat Pumping Appliances (ANSI 1994) to develop the emission testing procedure (ETP). The ETP was developed to minimize the economic impact on the UCEDHP industry while still meeting possible forthcoming requirements of the regulatory agencies. In English 27 Refs. EI98084328407 20. How to measure low-pressure steam boiler efficiency Katrakis, John T. (Energy Engineering Consultant) Zawacki, Thomas S. Source: ASHRAE Journal v 35 n 9 Sep 1993 Publ by ASHRAE 8p 0001-2491 Abstract: Higher efficiencies in existing boilers can be achieved by employing appropriate strategies to reduce off-cycle losses. Efficiency measurements of 11 steam boilers were completed based on two methods: an ANSI method for boilers and a Time-to-make-steam method, Results indicate that older intermediate-sized boilers exhibit wide variations in seasonal efficiency - from 38% to 74%. Recommendations on improving efficiency are given. In English 12 Refs. EI94011178562