Energy Analysis and Energy Conservation Options for the Addition to Records Storage Building

The energy use and peak load requirements of the addition to Records Storage Building in Austin, Texas were analyzed using the DOE 2.1B building energy simulation program. An analysis was made for the building as specified in schematic designs and primary drawings. To reduce the solar heat gain of the building through the windows and skylights, a glass with high reflectivity and low overall heat transfer coefficient was used to study the reduction of glass conduction and glass solar loads. Other options which were studied included increasing the wall and roof insulation,- reducing the light level, temperature setback, and implementing the proposed ASHRAE standards. Finally, the energy consumption of the building was compared with the energy consumption of the building with solar film and other options which conformed to the proposed ASHRAE energy standard

Two-Phase Flow of Two HFC Refrigerant Mixtures Through Short Tube Orifices, Draft Final Report

The need for new refrigerants was established when scientists first realized the ozone depleting effects of CFC and HCFC refrigerants. The chlorine atom in these refrigerants is capable of reaching the upper atmosphere where one chlorine atom can destroy more than 100,000 ozone atoms(Lang1ey 1994). Laws have been enacted to halt the destruction of the ozone layer and force industry to find replacements for the ozone depleting refrigerants. Section 608 of the Clean Air Act (1990) prohibited the venting of ozone depleting refrigerants as of July 1, 1992. In addition the Clean Air Act (1990) also requires the EPA to develop regulations limiting the emissions of ozone depleting refrigerants. Efforts are currently underway to find CFC replacements before the complete phaseout of CFC manufacturing in January of 1996. Much of the effort to replace CFC and HCFC refrigerants has centered on development of refrigerant mixtures that could replace R-22. Before systems can be designed with a new refrigerant (or mixture), thermodynamic and thermophysical properties must first be characterized. An important component in air conditioners is the expansion device. Because of their low cost, several manufacturers have chosen to use short tube orifices for the expansion device in their systems. Designing a system with an orifice requires knowledge of the flow characteristics of short tube orifices. Recent work on orifices has focused on R-12 and R-22 (Kim and O'Neal, 1993a; Aaron and Domanski, 1990; Krakow, 1988; and Mei, 1982). In addition, there are unpublished data on R-134a @m and ONeal, 1993b) and the effect of lubricants on flow characteristics (Kim, 1993; Kim and O'Neal, 1994b).The present study presents data for flow of two refrigerant mixtures through short tube orifices. The two mixtures were R3211251134a (23%/25%/52% on a mass percentage basis) and R321125 (50%/50%). The following presents results for the flow of these two refrigerants through short tube orifices of various diameters and lengths of 0.5 in (12.7 mm), 0.75 in (19.05 mm), and 1.00 in (25.4 mm) in a pure form and mixed with various mass percentages of oil

A Computer Analysis of Energy Use and Energy Conservation Options for a Twelve Story Office Building in Austin, Texas

The energy use of the Travis Building at Austin, Texas was analyzed using the DOE 2.1B building energy simulation program. An analysis was made for the building as specified in the building plans and as operated by the personnel currently occupying the building. The energy consumption of the building was compared with the energy consumption of the building modified to comply with the proposed ASHRAE 90.1p standards. The base design and the ASHRAE design of the Travis building were evaluated in Brownsville, Houston, Lubbock, and El Paso to study the influence of the weather on its energy consumption. In addition, a glass with high reflectivity and low overall heat transfer coefficient was used to study the reduction of glass conduction and glass solar loads. Finally, the energy consumption of the modified building was compared with the energy consumption of the modified building which conformed to the California energy standards

Development of Temperature and Humidity-Based Indicators for Diagnosing Problems in Low Tonnage, Split System Air Conditioners

This paper presents results of a survey of the literature and identifies the most common degraded conditions associated with low-tonnage air conditioners. Other laboratory studies as well as marketed diagnostic systems are also summarized. A procedure for identification of useful, low-cost temperature-based indicators of degraded conditions has been developed at the Energy Systems Laboratory, Texas A&M University in College Station, TX under contract to Honeywell. This paper presents the methodology used to identify the temperature-based indicators for the most common degraded conditions gleaned from the literature

The Impact of Residential Air Conditioner Charging and Sizing on Peak Electrical Demand

Electric utilities have had a number of air conditioner rebate and maintenance programs for many years. The purpose of these programs was to improve the efficiency of the stock of air conditioning equipment and provide better demand-side management. This paper examines the effect of refrigerant charging (proper servicing of the equipment), system sizing, and efficiency on the steady-state, coincident peak utility demand of a residential central air conditioning system. The study is based on the results of laboratory tests of a three-ton, capillary tube expansion, split-system air conditioner, system capacity and efficiency data available from manufacturer's literature, and assumptions about relative sizing of the equipment to cooling load on a residence. A qualitative discussion is provided concerning the possible impacts of transient operation and total energy use on utility program decisions. The analysis indicates that proper sizing of the unit is the largest factor affecting energy demand of the three factors (sizing, charging, and efficiency) studied in this paper. For typical oversizing of units to cooling loads in houses, both overcharging and undercharging showed significant negative impact on peak demand. The impacts of SEER changes in utility peak demand were found to be virtually independent of oversizing. For properly sized units, there was a small peak benefit to higher efficiency air conditioners

Trends in Building Energy Usage in Texas State Agencies

In late 1983, a cost containment program was initiated out of the governor's office directed at the major state agencies. The Energy Management Group at Texas A&M University provided technical expertise in obtaining agency energy usage and cost figures for the fiscal years 1981 to 1983. While there is considerable diversity from agency to agency, the trend is toward dramatically higher energy cost per square foot for virtually all agencies. This alarming trend can be partially explained by rising unit costs for gas and electricity and a lack of incentives for conservation efforts due to the method of utility budget allocations. A building standard signed into law in 1976 could have reduced energy consumption, but was never enforced. Beginning in fiscal year 1986, universities will be allowed to comingle utility money with capital operating money so that conservation can really pay off for them

Metering and Calibration in LoanSTAR Buildings

End-use metering in commercial buildings often requires installation of a large variety of transducers and data loggers. The metering installation group in the LoanSTAR monitoring program has the primary responsibility for the installation and maintenance of the metering hardware. This paper provides an overview of the responsibilities and first year experiences of the metering installation group of the LoanSTAR monitoring program. In addition, the calibration laboratory is also described

Assessing Ongoing Electronic Resource Purchases: Linking Tools to Synchronize Staff Workflows

Ongoing electronic resource purchases represent a substantial proportion of collections budgets. Recognizing the necessity of systematic ongoing assessment with full selector engagement, Columbia University Libraries appointed an Electronic Resources Assessment Working Group to promote the inclusion of such resources within our current culture of assessment. This article describes the Working Group’s implementation of an electronic resource renewal reminder system in Google Calendar, a calendar already in use by selectors for daily scheduling. In discussing this particular solution, this article shows how libraries can link existing systems together to move beyond their limitations and integrate them into existing staff workflows

An Evaluation of Improper Refrigerant Charge on the Performance of a Split System Air Conditioner with Capillary Tube Expansion

The effect of the improper charging on the performance (capacity, EER, power consumption, SEER, and coefficient of degradation) of a residential air conditioner during the steady state (wet and dry coils) and cycling operation was investigated. The fully charged condition was established as a base case. A full charge was obtained charging the unit to the superheat specified by the manufacturer's charging chart for specific set of indoor and outdoor temperatures. Once the full charge was determined, the unit was subjected to 20%, 15%, 10%, and 5% under and overcharging of refrigerant (by mass). The fully charged tests were compared to under and overcharging. The performance of the unit was evaluated as a function of charge as well as at four outdoor room temperatures (82°F, 90°F, 95°F, and 100°F). As the outdoor temperature increased, the total capacity and EER dropped. The investigation of improper charging showed that the total capacity, EER, and SEER were more sensitive to undercharging than overcharging conditions. A 20% undercharge resulted in a 21% reduction in SEER while a 20% overcharge produced a 11% reduction in SEER. Other data such as refrigerant flow rate, sensible heat ratio, superheat and subcooling are also presented

An Evaluation of Improper Refrigerant Charge on the Performance of a Split System Air Conditioner with a Thermal Expansion Valve

The effect of the improper charging on steady state and cyclic performance (capacity, EER, power consumption, SEER, and coefficient of degradation) of a residential air conditioner which utilized a thermal expansion valve was investigated. This study was the continuation of ESL/CON/88-1 performed by Mohsen Farzad and Dennis O'Neal. A fully charged condition was established as a base case. The full charge was obtained by charging the unit to the subcooling specified by the manufacturer for a specific indoor and outdoor temperatures. Once the full charge was determined, the unit was subjected to 40%, 30%, 20%, 15%, 10%, and 5% undercharging and 5%, 10%, 15%, and 20% overcharging of refrigerant by mass. The fully charged tests were compared to those for under and overcharging. The performance of the unit was evaluated as a function of charge as well as at four outdoor room temperatures (82°F, 90°F, 95°F, and 100°F). As the outdoor temperature increased, the total capacity and EER dropped. The maximum total capacity, EER, and SEER were found at 10% undercharging (12 6 oz). The capacity and efficiency (EER and SEER) of the unit were found to be less sensitive to under/overcharging than the unit with a capillary tube expansion previously studied. Other data such as refrigerant flow rate, sensible heat ratio, superheat and subcooling were also presented