[PDF] Economic Evaluation Of The Closed Loop Water Source Heat Pump System Versus Alternative Hvac Systems With And Without Gas Fired Central Plant Equipment eBook

Author : Van David Baxter
Publisher :
Page : pages
File Size : 35,43 MB
Release : 2006
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The long range strategic goal of the Department of Energy's Building Technologies (DOE/BT) Program is to create, by 2020, technologies and design approaches that enable the construction of net-zero energy homes at low incremental cost (DOE/BT 2005). A net zero energy home (NZEH) is a residential building with greatly reduced needs for energy through efficiency gains, with the balance of energy needs supplied by renewable technologies. While initially focused on new construction, these technologies and design approaches are intended to have application to buildings constructed before 2020 as well resulting in substantial reduction in energy use for all building types and ages. DOE/BT's Emerging Technologies (ET) team is working to support this strategic goal by identifying and developing advanced heating, ventilating, air-conditioning, and water heating (HVAC/WH) technology options applicable to NZEHs. Although the energy efficiency of heating, ventilating, and air-conditioning (HVAC) equipment has increased substantially in recent years, new approaches are needed to continue this trend. Dramatic efficiency improvements are necessary to enable progress toward the NZEH goals, and will require a radical rethinking of opportunities to improve system performance. The large reductions in HVAC energy consumption necessary to support the NZEH goals require a systems-oriented analysis approach that characterizes each element of energy consumption, identifies alternatives, and determines the most cost-effective combination of options. In particular, HVAC equipment must be developed that addresses the range of special needs of NZEH applications in the areas of reduced HVAC and water heating energy use, humidity control, ventilation, uniform comfort, and ease of zoning. In FY05 ORNL conducted an initial Stage 1 (Applied Research) scoping assessment of HVAC/WH systems options for future NZEHs to help DOE/BT identify and prioritize alternative approaches for further development. Eleven system concepts with central air distribution ducting and nine multi-zone systems were selected and their annual and peak demand performance estimated for five locations: Atlanta (mixed-humid), Houston (hot-humid), Phoenix (hot-dry), San Francisco (marine), and Chicago (cold). Performance was estimated by simulating the systems using the TRNSYS simulation engine (Solar Energy Laboratory et al. 2006) in two 1800-ft{sup 2} houses--a Building America (BA) benchmark house and a prototype NZEH taken from BEopt results at the take-off (or crossover) point (i.e., a house incorporating those design features such that further progress towards ZEH is through the addition of photovoltaic power sources, as determined by current BEopt analyses conducted by NREL). Results were summarized in a project report, HVAC Equipment Design options for Near-Zero-Energy Homes--A Stage 2 Scoping Assessment, ORNL/TM-2005/194 (Baxter 2005). The 2005 study report describes the HVAC options considered, the ranking criteria used, and the system rankings by priority. In 2006, the two top-ranked options from the 2005 study, air-source and ground-source versions of an integrated heat pump (IHP) system, were subjected to an initial business case study. The IHPs were subjected to a more rigorous hourly-based assessment of their performance potential compared to a baseline suite of equipment of legally minimum efficiency that provided the same heating, cooling, water heating, demand dehumidification, and ventilation services as the IHPs. Results were summarized in a project report, Initial Business Case Analysis of Two Integrated Heat Pump HVAC Systems for Near-Zero-Energy Homes, ORNL/TM-2006/130 (Baxter 2006). The present report is an update to that document. Its primary purpose is to summarize results of an analysis of the potential of adding an outdoor air economizer operating mode to the IHPs to take advantage of free cooling (using outdoor air to cool the house) whenever possible. In addition it provides some additional detail for an alternative winter water heating/space heating (WH/SH) control strategy briefly described in the original report and corrects some minor errors.

Author : David D. Vanderburg
Publisher :
Page : 244 pages
File Size : 47,63 MB
Release : 2002
Category : Ground source heat pump systems
ISBN : 9781423511694

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To sustain the United States current affluence and strength, the U.S. Government has encouraged energy conservation through executive orders, federal and local laws, and consumer education. A substantial reduction in U.S. energy consumption could be realized by using geothermal heat pumps to heat and cool buildings throughout the U.S., though initial installation cost are a deterrent. This thesis uses Monte Carlo simulation to predict energy consumption, life cycle cost and payback period for the vertical closed-loop ground source heat pump (GSHP) relative to conventional heating ventilation and air conditioning (HVAC) systems: air-source heat pumps (ASHP), air-cooled air conditioning with either natural gas, fuel oil, or liquid petroleum gas furnaces, or with electrical resistance heating. The Monte Carlo simulation is performed for a standard commercial office building within each of the 48 continental states. Regardless of the conventional HVAC system chosen, the simulation shows that for each state the GSHP has the highest probability of using less energy and having a lower operating and life cycle cost than conventional HVAC systems; however, initial installation cost are typically twice that of conventional HVAC systems and payback periods vary greatly depending on site conditions. The average 50th percentile GSHP payback period in the U.S. was 7.5 years compared against the ASHP and 9.2 years compared against the air-cooled air conditioning with natural gas furnace. However, these values vary greatly depending on location and are most sensitivity to ground thermal conductivity, utility prices, and HVAC efficiency ratings. Under the right conditions, payback for geothermal heat pumps can be much shorter and the model developed in this research can help predict energy savings and payback periods for a given site.

Author : Ryan Duwain Warren
Publisher :
Page : 282 pages
File Size : 39,70 MB
Release : 2005
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The objective of this study was to evaluate alternative heating and cooling approaches for a non-typical residence including geothermal and radiant floor heating technology. The analysis included four main components: estimating the design heating and cooling loads of the home, developing alternative approaches for heating and cooling the residence, designing an hourly energy use and heating, ventilating, and air conditioning (HVAC) system performance simulation model for the home over a period of one year, and estimating economic factors for each alternative system. Four alternative approaches for conditioning the case study home were developed and evaluated. These alternatives include systems that utilize either a water-to-air ground-source geothermal heat pump or a liquid-propane gas furnace for the forced air conditioning and either an electric boiler, liquid propane boiler, or a water-to-water ground-source geothermal heat pump for hydronic heating. Using the design heating and cooling loads on the home, specific equipment for each alternative was selected. The hourly energy demand on the home was simulated considering conduction heat transfer through the structure, solar loads, infiltration effects, and internal gain. The HVAC system model estimates the hourly performance of each alternative system given the hourly demand on the home. In addition, the approximate monthly and annual costs associated with each system were determined. Typical Meteorological Year (TMY2) data was used to estimate hourly weather and solar conditions expected at the geographical location of the home over a one year period. The economics for each alternative approach was evaluated based on a life-cycle-cost analysis. All annual expenses and savings for each approach were estimated over the assumed life of each system. The present-value and payback-period for each system was determined and compared. It was found that the approach utilizing a ground-source geothermal heat pump and electric hydronic boiler would be the most economical.

Author : Carl J. Bliem
Publisher :
Page : 0 pages
File Size : 25,96 MB
Release : 1988
Category : Heat pumps
ISBN :

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This report extends the findings of a study on the cost of delivering process heat with state-of-the-art heat pump systems originally reported in EGG -2408, "A Comparative Economic Evaluation of Industrial Heat Pumps." The original report considered heat pump of a 30 MM Btu/hr size, receiving heat from a waste -heat source at220°F. This report extends the work to a 10 MM Btu/hr size and to waste -heat sources at 180°F and 320°F. Results of the original study are being used to define economic performance which must be met or improved upon by advanced heat pump concepts in order to warrant Department of Energy (DOE) development support. This work will extend the range of applicability to other sizes and waste -heat source temperatures. Sixteen heat pump systems were configured for relative cost comparisons for each waste -heat source and size. These systems consisted of electrically -driven, prime energy -driven, and waste energy -driven reverse Rankine cycle heat pumps of the open, semi open, and closed type. In addition, a waste energy -driven absorption heat pump was analyzed. A conceptual design of each system was created using off -the -shelf components generally available to engineering firms. The performance of each system was assessed, the major components sized, and the installed cost determined. Maintenance costs were estimated. Finally, the relative cost of energy delivered by each system was estimated, and the cost of delivery heat with state-of-the-art heat pumps was determined.

Author : Cary Jonathon Lane
Publisher :
Page : 166 pages
File Size : 19,57 MB
Release : 2005
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Heat pump systems are becoming a popular choice for residential heating and cooling across the United States. Heat pumps are among the cleanest and best energy- and cost-efficient heating and cooling systems available today. However, cost is a prime motivator when choosing among residential heating and cooling systems and it is therefore desirable to analyze the costs associated with heat pump system operation. This research provides a method of direct comparison between the economics of air-source and ground-source heat pump system operation. The objective is to provide a cost comparison with respect to climate locations across the United States, since heat pump performance is heavily influenced by operating environmental conditions such as the ambient air temperature. A purely analytical approach is used for the comparison, avoiding the complexities and costs associated with surveys or experiments, and obtaining actual utility information. Heat pump systems are briefly surveyed, and the thermodynamic operation of vapor compression refrigeration cycles is examined. Analytic models are developed to simulate heating and cooling operation of dual-mode air- and ground-source heat pumps based upon readily available climate data. Finally, a cost ratio relationship is developed to directly compare the associated operating costs for air- and ground-source heat pump systems for a 31 city sample covering much of the continental United States. The annual cost ratio provides the opportunity to evaluate potential cost savings for the operation of air- or ground-source heat pump installations.

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Page : 0 pages
File Size : 19,99 MB
Release : 1979
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Heat Pump Centered-Integrated Community Energy Systems (HP-ICES) show the promise of utilizing low-grade thermal energy for low-quality energy requirements such as space heating and cooling. The Heat Pump - Wastewater Heat Recovery (HP-WHR) scheme is one approach to an HP-ICES that proposes to reclaim low-grade thermal energy from a community's wastewater effluent. This report develops the concept of an HP-WHR system, evaluates the potential performance and economics of such a system, and examines the potential for application. A thermodynamic performance analysis of a hypothetical system projects an overall system Coefficient of Performance (C.O.P.) of from 2.181 to 2.264 for waste-water temperatures varying from 50°F to 80°F. Primary energy source savings from the nationwide implementation of this system is projected to be 6.0 QUADS-fuel oil, or 8.5 QUADS - natural gas, or 29.7 QUADS - coal for the period 1980 to 2000, depending upon the type and mix of conventional space conditioning systems which could be displaced with the HP-WHR system. Site-specific HP-WHR system designs are presented for two application communities in Georgia. Performance analyses for these systems project annual cycle system C.O.P.'s of 2.049 and 2.519. Economic analysis on the basis of a life cycle cost comparison shows one site-specific system design to be cost competitive in the immediate market with conventional residential and light commercial HVAC systems. The second site-specific system design is shown through a similar economic analysis to be more costly than conventional systems due mainly to the current low energy costs for natural gas. It is anticipated that, as energy costs escalate, this HP-WHR system will also approach the threshold of economic viability.