Inside An Energy-Efficient Upgrade for a Historical Army Band Hall

This paper discusses the Heating, Ventilation, and Air Conditioning (HVAC) system designed as part of amajor renovation project to the historical San Antonio building that serves as home to the U.S. Army Band known as “Fort Sam Houston’s Own.” The HVAC system design provides an innovative new heating and cooling system intendedtosaveenergyandgivethefacilityamoresustainablelong-termlife.ThefacilityislocatedinsouthTexas and was originally cooled by multiple two-pipe indoor air-handler units fed by an air-cooled chiller and gas-fired boiler. Outside air was provided to the air handlers from window louvers and roof vents. Such a ventilation approachisnotrecommendedbytheU.S.DepartmentofDefenseUnifiedFacilitiesCriteria(UFCs),theAmerican Society of Heating, Refrigerating and Air-Conditioning (ASHRAE), or industry standards. The new system relies instead on aDedicated OutsideAirSystem (DOAS),Fan CoilUnits(FCUs),and energyrecovery wheelstobring thebuildinguptomodernstandards

The Design Estimate of a Warehouse Refrigeration System

The intention of this project was to provide a design and cost estimate for the refrigeration systems within an industrial cold storage distribution center for Magnolia Country Frozen Foods, Inc. in East Rutherford, NJ. The facility includes eighteen 300,000 ft3 units (200 ft x 100 ft x 15 ft). These units require 200 tons of refrigeration at a maintained temperature of 0oF. This project\u27s scope included choosing an optimal refrigeration system, selecting a refrigerant for use within the system, and providing a cost estimate for the purchase of the refrigeration system equipment and for the yearly cost associated with running and maintaining the system. In our work researching and preparing to complete the estimate for the system, our top considerations included efficient thermodynamic performance, safety, global warming potential, refrigerant phase-out status, and cost. The refrigeration system equipment for each unit represented in the cost estimate includes a compressor, two heat exchangers, and refrigerant to load each system. The final estimate represents a safe, efficient, cost-effective option to implement in the construction of the warehouse refrigeration complex

Interim And Long-Term Low-GWP Refrigerant Solutions For Air Conditioning

This paper will update on the feasibility status from the global test research efforts for ‘interim’ near drop-in refrigerants with low global warming potential (LGWP) with focus on R410A replacement for Unitary A/C & H/P. R32 and the HFO blends offer near drop-in solutions with a reasonable balance of trade-offs among GWP, efficiency, A2L flammability, and cost after  the building codes are available for commercialization. With the advent of further GWP phase down driven by the December 2015 Climate Change Agreement in Paris coupled with the imminent U.S. EPA SNAP de-listing and the U.S. DOE mandating new higher efficiency standards taking effect in 2020+, there is even more pressure for finding ‘long-term’ refrigerant solutions to meet the 15-20% GWP cap for 2030+ that can sustain efficiency, reduce charge requirement and are affordable. Theoretical and test results from various compressor and system tests with R32 and the HFO blends will be presented as ‘interim’ 2020+ solutions. Long-term 2030+ solutions and their tradeoffs are conceptualized and discussed for typical A/C residential and commercial applications from both GWP and LCCP standpoint including implications on HVAC system architecture.

Optimization of a Residential Air Source Heat Pump using Heat Exchangers with Small Diameter Tubes

Heat exchangers play significant role in refrigeration and air conditioning systems. Ongoing research aims to improve, or at least maintain, the system performance while reducing the size, weight and cost of the heat exchangers. This in turn leads to lower system refrigerant charge and reduced environmental impact. Using heat exchangers with small tube diameters (less than 5 mm) instead of large tube diameters has been shown to be a promising solution to meet the aforementioned goals. However, shifting towards mall tube diameters requires in-depth analysis and optimization of several heat exchanger design parameters. This paper presents a multi-objective optimization of a residential air source heat pump system using genetic algorithms with a particular focus on the use of small diameter tubes in the heat exchangers. The objectives are to minimize the heat exchangers’ cost and maximize the system performance. The goal of this study is to determine the potential material savings and cost reduction when using tube diameters between 3 mm and 5 mm in the heat exchangers. In addition to the tube diameters, multiple fin types, tube spacing and fin densities are also investigated. The optimization is carried out for R-410A, and a lower-GWP alternative, R-32. The system utilizing the improved heat exchanger designs has a cost reduction of 50% in comparison to the baseline system. Also, the improvements in the system’s COP and the system charge reduction are around 20% and 35%, respectively.

HVAC system size – getting it right

There is evidence that many heating, ventilating & air conditioning (HVAC) systems, installed in larger buildings, have more capacity than is ever required to keep the occupants comfortable. This paper explores the reasons why this can occur, by examining a typical brief/design/documentation process. Over-sized HVAC systems cost more to install and operate and may not be able to control thermal comfort as well as a “right-sized” system. These impacts are evaluated, where data exists. Finally, some suggestions are developed to minimise both the extent of, and the negative impacts of, HVAC system over-sizing, for example: • Challenge “rules of thumb” and/or brief requirements which may be out of date. • Conduct an accurate load estimate, using AIRAH design data, specific to project location, and then resist the temptation to apply “safety factors • Use a load estimation program that accounts for thermal storage and diversification of peak loads for each zone and air handling system. • Select chiller sizes and staged or variable speed pumps and fans to ensure good part load performance. • Allow for unknown future tenancies by designing flexibility into the system, not by over-sizing. For example, generous sizing of distribution pipework and ductwork will allow available capacity to be redistributed. • Provide an auxiliary tenant condenser water loop to handle high load areas. • Consider using an Integrated Design Process, build an integrated load and energy use simulation model and test different operational scenarios • Use comprehensive Life Cycle Cost analysis for selection of the most optimal design solutions. This paper is an interim report on the findings of CRC-CI project 2002-051-B, Right-Sizing HVAC Systems, which is due for completion in January 2006

Computer Simulation of A New Method to Dry Lumber Using Solar Energy and Absorption Refrigeration

A mathematical model for a Solar-absorption dehumidification lumber dryer has been developed. Performance of a commercial size lumber kiln of 60 m3 (25,000 board-feet) was simulated for a southern Illinois climate for four different seasons of the year. The solar-absorption system dried yellow-poplar lumber as fast as a conventional vapor-compression dehumidification system while reducing the electrical energy costs by 85%. Capital costs and yearly fuel costs were compared to an oil-fired boiler system, a wood-fired boiler system, and a vapor-compression lumber-drying system

Evaluation of the heat and energy performance of a datacenter by a new efficiency index: Energy Usage Effectiveness Design - EUED

Data Centers are growing steadily worldwide and they are expected to continue on growing up to 53% in 2020. Due to this growth the energy efficiency in this type of building is essential. There are methodologies to measure this efficiency; one example is PUE (Power Usage Effectiveness). The unit suggested for measuring efficiency at the design stage would be the EUED (Energy Usage Efficiency Design) with this will be used data to use "free cooling" and adiabatic system in some cases, a comparison will be made only considering the equipment in the worst situation. It also uses the study of enthalpy utilization as a new methodology to obtain the results. By doing so, differences were found, between cities than 1.21% of São Paulo in relation to Curitiba and 10.61% of Rio de Janeiro in relation to Curitiba. The indices obtained by applying the EUED index were 1.245 kW.kW- 1 for Curitiba, 1.260 kW.kW-1 for São Paulo and 1.377 kW.kW-1 for Rio de Janeiro, respectively, giving a difference of 16.86% for Curitiba of 16.19% for São Paulo and 10.31% for Rio de Janeiro in relation to PUE COA (Power Usage Effectiveness Constant Outdoor Air).info:eu-repo/semantics/publishedVersio