Heat Pump Do It Yourself Install

Geothermal Heat Pumps Installation Guide

Installing a Geothermal Heat Pump Will Save you thousands in heating and cooling costs, and will repay itself many times over. This guide is filled with factual information to help you get fired up so you can quickly and easily make decisions to heat and cool your private home. Geothermal heating and cooling technology provides exceptional performance and the United States Environmental Protection Agency (Epa) agrees that a geothermal heat pump is the most energy-efficient, environmentally clean, and most cost-effective space conditioning system available. The guide contains the information you need, when you need it. Compiled in an easy-to-understand visual format. Includes: Explanation of geothermal heat transfer, Descriptions of the types of geothermal systems, Space requirements, Tips on the right system for your needs.

Geothermal Heat Pumps Installation Guide Overview

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Groundsource Heat Pumps

Ground-source heat pumps are known by a variety of names geoexchange heat pumps, ground-coupled heat pumps, geothermal heat pumps, earth-coupled heat pumps, ground-source systems, groundwater source heat pumps, well water heat pumps, solar energy heat pumps, and a few other variations. Some names are used to describe more accurately the specific application however, most are the result of marketing efforts and the need to associate (or disassociate) the heat pump systems from other systems. This chapter refers to them as ground-source heat pumps except when it is necessary to distinguish a specific design or application of the technology. A typical ground-source heat pump system design applied to a commercial facility is illustrated in Figure 28.1. It is important to remember that the primary equipment used for ground-source heat pumps are water-source heat pumps. What makes a ground-source heat pump different (unique, efficient, and usually more expensive to install) is the...

818 Enhancing Waste Heat with Heat Pumps

Heat pumps offer only limited opportunities for waste-heat recovery simply because the cost of owning and operating the heat pump may exceed the value of the waste heat recovered. A heat pump is a device that operates cyclically so that energy absorbed at low temperature is transformed through the application of external work to energy at a higher-temperature which can be absorbed by an existing load. The commercial mechanical refrigeration plant can be utilized as a heat pump with small modifications, as indicated in Figure 8.2. The coefficient of performance (COP) of the heat pump cycle is the simple ratio of heat delivered to work required

2852 Where to Apply Ground Source Heat Pumps

Ground-source heat pumps are generally applied to air-conditioning and heating systems, but may also be used in any refrigeration application. The decision whether to use a ground-source heat pump system is driven primarily by economics. Almost any HVAC system can be designed using a ground-source heat pump. The primary technical limitation is a suitable location for the ground-coupling system. The following list identifies some of the best applications of ground-source heat pumps. Ground-source heat pumps are probably least cost-prohibitive in new construction the technology is relatively easy to incorporate. Ground-source heat pumps can also be cost effective to replace an existing system at the end of its useful life, or as a retrofit, particularly if existing ductwork can be reused with minimal modification. In areas where natural gas is not available or where the cost of natural gas or other fuel is high compared with electricity, ground-source heat pumps are economical. They...

1452 The heat pump cycle

The evaporation of citrus juices at temperatures up to 328 K, or of pharmaceutical products at even lower temperatures, has led to the development of an evaporator incorporating a heat-pump cycle using a separate working fluid. The use of the heat pump cycle, with ammonia as the working fluid is shown in Figure 14.13. In this arrangement, ammonia Figure 14.13. Heat pump cycle using ammonia

Towers Heat Pumps and Heat Recovery

The condenser is a heat source, and this heat must be rejected in order to complete the refrigeration cycle. When there is no practical use for the condenser heat, either because of condition (i.e., temperature or quantity) or the time when it is available, it must be rejected to the ambient environment. When this condenser heat is productively used, the refrigeration system may be considered a heat pump. Refrigeration-cycle systems can be, in fact, very efficient heaters, sometimes generating four to five times the energy in the form of heat as they require as input. Some refrigeration-cycle systems reverse their cycles to deliver either heating or cooling, while others are used only for heating. Some can do both simultaneously, by directing the rejected heat to a productive use while in the cooling mode. These systems may be considered a type of heat recovery heat pump. They recover refrigeration cycle-generated heat, normally rejected to the outside environment, for productive use,...

Absorption Cycle and Engine Driven Heat Pumps

While almost all of the heat pumps currently in commercial operation use electric motor-driven vapor compression systems, the compressor itself is indifferent Fig. 36-24 Geothermal Heat Pump Loop System. Source The Trane Company Fig. 36-24 Geothermal Heat Pump Loop System. Source The Trane Company NH3-H2O based GAX cycle, which are discussed in Chapter 38. While the basic GAX cycle is an excellent heat producer, it is not as thermally efficient in the cooling mode as other cooling system alternatives. The advanced GAX-cycle machines, however, are expected to improve the cooling-side efficiency. Under standard ARI conditions, this unit is expected to achieve a cooling COP of 0.95 and a heating COP of 1.55. These COP figures are particularly impressive because these are air source heat pumps operating through a much wider temperature range than can be achieved with conventional absorption cycle machines. to its driver and may be driven with any type of prime mover. Figure 36-25 shows a...

19 Stirling Engines For Heat Pumps Stationary Power And Totalenergy Systems

Stirling engines are under study or development for a variety of non-automotive applications that can be broadly classified into three groups heat pumps, stationary power generation and total energy or co-generation systems. A total-energy system will therefore include a stationary power generator and, in all probability, a sub-system operating as a heat purnp. However, a stationary power generator or heat pump is not necessarily part of a total-energy system not need the heat pump incorporate a stationary power generator. Nevertheless, they can be related and seem to fit together in a common grouping although from hereon we shall consider them all under separate headings.

Heat Pumps

There are numerous types of heat pump system designs and various heat source and heat sink media used. Some systems reverse their cycles to deliver both heating and cooling, while others are used only for heating. Common to all is the same basic operating principle extract heat from one medium and deliver to another. As a means of understanding the basic operation of a heat pump cycle, consider the operation of a simple air-to-air reverse flow direct expansion (DX) heat pump. As shown in Figure 36-21, with a basic DX type heat pump operating in the cooling mode, heat from the inside conditioned space is absorbed by the vaporizing refrigerant in the indoor coil. The heat-laden refrigerant is pumped outdoors by the compressor, where the heat is rejected by the outdoor coil. The refrigerant is then condensed and pumped back to the indoor coil, where the cycle is repeated. Fig. 36-21 Heat Pump Operating in Cooling Mode. Source Carrier Corp. Fig. 36-22 Heat Pump Operating in Heating Mode....

Types of Heat Pumps

The air-to-air system with a refrigerant changeover system described above is one of several types of commercially available heat pumps. Following are descriptions of various heat pump system designs. As an alternative to the refrigerant changeover design discussed and shown graphically above, the thermal cycle change can also be done with an air changeover. In this type of design, one heat exchanger coil is always the evaporator and the other is always the condenser. The positioning of the dampers causes the change from cooling to heating. Thus, instead of reversing the refrigerant flow, the indoor and outdoor airflows are redirected to accomplish the same ends. This is usually the least costly type of heat pump. As with any air-cooled system, heat transfer is not as efficient as with water systems. At low ambient air temperature conditions, less heat is available and or energy must be supplied to defrost the coil. (similar to indirect free cooling systems). Another alternative is to...

Heat Pumping

A significant saving in condenser duty can be achieved by compressing the overhead vapour to a temperature that can be used to reboil the bottoms liquid. A typical heat-pumped column is shown in Figure 7. The compressor is a significant addition to the total capital costs. This scheme is feasible if the distillation involves a close boiling mixture where the top and bottom temperatures are not significantly different. The most common industrial application is propane propylene splitters, which require large Figure 7 Heat-pumped column. Figure 7 Heat-pumped column. amounts of heating and cooling energy. A large reduction in cooling water and wastewater products provides a large incentive to heat pump these types of columns.

Utility Information Service or Government Agency Tech Transfer Literature

Proceedings of the Workshop on Ground-Source Heat Pumps. From the workshop held in Albany, New York, October 27 through November 1, 1986. HPC-WR-2. International Energy Agency Heat Pump Center. Goldfish, L.H., and R.A. Simonelli. 1988. Ground-Source and Hydronic Heat Pump Market Study. EM-6062, Electric Power Research Institute, Palo Alto, California. Ground Source Systems Educational and Marketing Material Catalog. International Ground Source Heat Pump Association, Stillwater, Oklahoma. GS-Systems An Answer to U.S. Energy and Environmental Concerns A comprehensive report on ground-source heat pumps and their benefits (not dated). International Ground-Source Heat Pump Association, Oklahoma State University, Stillwater, Oklahoma. *Pratsch, L.W. 1990. Geothermal Heat Pumps A Major Opportunity for the Utility Industry. Presented at the Geothermal Energy Conference, Columbus, Ohio, November 14, 1990. Scofield, M., and P. Joyner. September 1991. Heat Pumps for...

User and Third Party Field and Lab Test Reports14

Comparison of Water-Source and Air-Source Heat Pumps in Northern Environment, a chapter in Heat Pump Technology for Saving Energy. Noyes Data Corporation, Park Ridge, New Jersey. *Hughes, P.J. and J.A. Shonder. 1998. The Evaluation of a 4000-Home Geothermal Heat Pump Retrofit at Fort Polk, Louisiana Final Report. ORNL CON-460, Oak Ridge National Laboratory, Oak Ridge, Tennessee. Phetteplace, G., H. Ueda, and D. Carbee. 1992. Performance of Ground-Coupled Heat Pumps in Military Family Housing Units. Solar Engineering. G0656A-1992, American Society of Mechanical Engineers, New York, NY. Phetteplace, G. 1995. Ground-Coupled Heat Pumps for Family Housing Units. FEAP-UG-CRREL-95 01, U.S. Army Center for Public Works, Alexandria, Virginia.

Hot Water Recovery Desuperheating

The use of heat pumps to provide hot water is becoming common. Because of their high efficiency, this practice makes economic sense. Most manufacturers offer an option to include desuperheating heat exchangers to provide hot water from a heat pump. These dual-wall heat exchangers are installed in the refrigerant loop to recover high temperature heat from the superheated refrigerant gas. Hot-water recovery systems can supplement, or sometimes replace, conventional facility water-heating systems. With the heat pump in cooling mode, hot-water recovery systems increase system operating efficiency while acting as a waste-heat-recovery device and provide essentially free hot water. When the load is increased during the heating mode, the heat pump still provides heating and hot water more efficiently and less expensively than other systems.

Refrigeration Cycle Heat Recovery

Any type of refrigeration cycle system that transfers heat for beneficial purposes may be considered a heat pump. Refrigeration cycle systems that provide cooling but also recover heat rejected from the refrigerant to provide useful heating may be considered a type of heat recovery heat pump. These are differentiated from reverse cycle systems in that when they operate, they always provide cooling with conventional cycle operation. An additional feature is that they recover refrigeration cycle-generated heat, normally rejected to the outside environment, for productive use. Condenser heat recovery systems are typically used for larger systems featuring centrifugal or screw compressors. These systems may feature either a single condenser or a dual-condenser configuration with a dedicated heat recovery condenser. In applications in which the heating load exceeds the cooling load at all times, the chiller essentially functions as a heat pump with all of the rejected heat from the...

2855 Equipment Warranties

The prospective user should ask potential suppliers, contractors, and installers about equipment warranties. The heat pump equipment is typically guaranteed free from manufacturer defects from 1 to 5 years. Some manufacturers offer extended warranties up to 10 years. Residential applications have been found to have longer warranties than commercial applications.

2843 Ground Coupled System Types

The ground-coupling systems used in ground-source heat pumps fall under three main categories closed-loop, open-loop and direct-expansion. These are illustrated in Figure 28.2 and discussed in the following sections. The type of ground coupling employed will affect heat pump system performance (therefore the heat pump energy consumption), auxiliary pumping energy requirements, and installation costs. Choice of the most appropriate type of ground coupling for a site is usually a function of specific geography, available land area, and life-cycle cost economics.

287 Hypothetical Case Studies

The purpose of these hypothetical case studies is to assist the energy manager or facility engineer in estimating the energy consumption and costs associated with the construction and operation of ground-source heat pump systems and comparing them with those for conventional HVAC technologies. The goal is to estimate energy consumption and savings, not to design systems. There are several methods for estimating energy consumption of HVAC technologies, from simplistic degree-day calculations to sophisticated hour-by-hour energy modeling and simulation systems supported by computer programs. The examples used in this chapter are based on an outdoor temperature bin method. This method is described in more detail in Closed-Loop Closed-Source Heat Pump Systems Installation Guide (OSU 1988). Two case studies were developed for this chapter. In both, estimates of the potential energy consumption and life-cycle costs of the ground-source heat pump technology are compared with conventional...

2881 The Technologys Development

The ground-source heat pump technology has been shown through laboratory testing, field testing, and theoretical analysis to be technically valid and economically attractive in many applications. Energy savings have been verified in a large number of field tests over the past 30 years. In several installations, reductions in maintenance

Cooling TowerSupplemented System

The ground-coupling system is typically the largest component of the total installation cost of a ground-source heat pump. In southern climates or in thermally heavy commercial applications where the cooling load is the driving design factor, supplementing the system with a cooling tower or other supplemental heat rejection system can reduce the required size of a closed-loop ground-coupling system. The supplemental heat rejection system is installed in the loop by means of a heat exchanger (typically a plate and frame heat exchanger) between the facility load and the ground couple. A cooling tower system is illustrated in Figure 28.5. The cooling tower acts to pre-cool the loop's heat transfer fluid upstream of the ground couple, which lowers the cooling-load requirement on the ground-coupling system. By significantly reducing the required size of the ground-coupling system, using a cooling tower can lower the overall installation cost. This type of system is operating successfully...

Figure 286 Solarassisted system for heatingdominated loads

Stem from the performance of the ground-coupling system. Today, software tools are available to support the design of the ground-coupling systems that meet the needs of designers and installers. These tools are available from several sources, including the International Ground-Source Heat Pump Association (IGSHPA). In addition, several manufacturers have designed their own proprietary tools more closely tuned to their particular system requirements. Ground loops can be placed just about anywhere under landscaping, parking lots, or ponds. Selection of a particular ground-coupling system (vertical, horizontal, spiral, etc.) should be based on life-cycle cost of the entire system, in addition to practical constraints. Horizontal closed-loop ground-coupling systems can be installed using a chain-type trenching machine, horizontal boring machine, backhoe, bulldozer, or other earth-moving heavy equipment. Vertical applications (for both open and closed systems) require a drilling rig and...

Underground Soil Temperature

The soil temperature is of major importance in the design and operation of a ground-source heat pump. In an open-loop system, the temperature of groundwater entering the heat pump has a direct impact on the efficiency of the system. In a closed-loop system and in the direct-expansion system, the underground temperature will affect the size of the required ground-coupling system and the resulting operational effectiveness of the underground heat exchanger. Therefore, it is important to determine the underground soil temperature before selecting a system design.

Technology Description

The second alternative is a rooftop air-source heat pump system with electric resistance supplemental heaters. To meet the cooling requirements during the actual cooling design day, 10 rooftop units are required. To meet the added load during the heating design day, each rooftop unit is equipped with a 50-kW supplemental heater. The third alternative is a ground-source heat pump system using extended range water-source heat pumps and a vertical closed-loop ground-coupling system. To meet the cooling requirements during the actual cooling design day, 35 units are required. To meet the added load during the heating design day, each unit is equipped with a 10-kW supplemental heater. The water-loop system employs a variable-speed drive for added energy savings.

Soil and Rock Classification

The most important factor in the design and successful operation of a closed-loop ground-source heat pump system is the rate of heat transfer between the closed-loop ground-coupling system and the surrounding soil and rock. The thermal conductivity of the soil and rock is the critical value that determines the length of pipe required. The pipe length, in turn, affects the installation cost as well as the operational effectiveness, which in turn affects the operating cost. Because of local variations in soil type and moisture conditions, economic designs may vary by location. Soil classifications include coarse-grained sands and gravels, fine-grained silts and clays, and loam (equal mixtures of sand, silt, and clay). Rock classifications are broken down into nine different petrologic groups. Thermal conductivity values vary significantly within each of the nine groups. Each of these classifications plays a role in determining the thermal conductivity and thereby affects the design of...

911 Envelope Analysis For New Buildings

The advantage of this multiple-measure method over a single-measure method, such as the degree day method, is the ability to accommodate other temperature-dependent phenomena in the analysis. For example, the power requirement and capacity of an air-to-air heat pump are extremely temperature dependent. This dependency is easily accommodated by the bin method.

2882 Technology Outlook

The outlook for ground-source heat pumps is bright. In 1999, an estimated 400,000 ground-source heat pumps were operating in residential and commercial applications, up from 100,000 in 1990. In 1985, it was estimated that only around 14,000 ground-source heat pump systems were installed in the United States. Annual sales of approximately 45,000 units were reported in 1997. With a projected annual growth rate of 10 , 120,000 new units would be installed in 2010, for a total of 1.5 million units in 2010. In Europe, the estimated total number of installed ground-source heat pumps at the end of 1998 was 100,000 to 120,000. Nearly 10,000 ground-source heat pumps have been installed in U.S. federal buildings, over 400 schools, and thousands of low-income houses and apartments.

288 The Technology In Perspective

The future of ground-source heat pump technology looks good because there are many potential commercial applications. Although installation costs are typically higher for ground-source heat pumps than for other technologies, the decision criteria should be based on life-cycle costs rather than first costs then, a ground-source heat pump system can be the most cost-effective alternative. According to the EPA study, Space Conditioning The Next Frontier, ground-source heat pumps are consistently the most energy-efficient, least polluting of all space conditioning technologies throughout the The limited industry volume has been one of the factors holding back the development of a broader contractor base. The technology has not enjoyed broad national promotion. According to the results of one survey on the barriers to ground-source heat pumps, HVAC, plumbing, and Architectural Engineering contractors are conservative, and are therefore reluctant to commit to what they regard as innovative...

2856 Energy Codes and Standards

Applications of ground-source heat pumps are subject to building and facility energy codes and standards. In addition, the equipment used is subject to commercial equipment energy codes and standards. Most energy regulations that impact commercial buildings derive from ASHRAE standards, specifically ASHRAE Standard 90.1. Minimum equipment efficiency standards, as identified in ASHRAE Standard 90.1-2004, for commercial equipment relative to ground-source heat pumps are shown in Table 28.1. Although codes and standards identify minimum efficiencies, such as those identified above, they do not fully communicate the energy efficiency that is achieved by today's heat pumps. A review of manufacturer's literature on commercially available equipment indicates that cooling efficiencies7 (EERs) of 13.4 to 20 Btu W-h and heating efficiencies (COPs) of 3.1 to 4.3 are readily available.8 When 7Rating based on ANSI ARI ASHRAE ISO Standard 13256-1-2005 for closed-loop ground-source heat pumps....

Functional Description

The turboexpander in combination with a compressor and a heat exchanger functions as a heat pump and is analyzed as follows In Fig. 29-44 consider the compressor and aftercooler as an isothermal compressor operating at T2 with an efficiency Ec, and assume the working fluid to be a perfect gas. Further, consider the removal of a quantity of heat Qe by the turboexpander at an average low temperature Ti. This requires that it deliver shaft work equal to Qe. Now, make the reasonable assumption that one-tenth of the temperature drop in the expander is used for the temperature difference in the heat exchanger. If the expander efficiency is Ne and this efficiency is multiplied by 0.9 to include the effect of the temperature difference in the heat exchanger, the needed ideal enthalpy drop across the expander is

Packaged Terminal Air Conditioners

Individual air-to-air (air-source) heat pumps can also be installed as a packaged system. A heat pump is essentially a vapor-compression air-conditioner which can be reversed to extract heat from the outdoor environment and discharge it into the occupied space. A significant drawback to air-source heat pumps is that vapor compression refrigeration becomes inefficient when the evaporator is forced to extract heat from a source whose temperature is 30 F (0 C) or below. In large systems, heat pumps can utilize a source of circulating water from which to extract heat during cold weather, so that the evaporator temperature never approaches 30 F (0 C). The circulating water would be heated in the coldest weather, and could be cooled by a cooling tower to receive rejected heat during warm weather. These closed-loop heat pumps are discussed under all-water systems above.

2841 How the Technology Works

Heat normally flows from a warmer medium to a colder one. This basic physical law can only be reversed with the addition of energy. A heat pump is a device that does so by essentially pumping heat up the temperature scale, then transferring it from a cold material to a warmer one by adding energy, usually in the form of electricity. A heat pump functions by using a refrigerant cycle similar to the household refrigerator. In the heating mode, a heat pump removes the heat from a low temperature source, such as the ground or air, and supplies that heat to a higher temperature sink, such as the heated interior of a building. In the cooling mode, the process is reversed and the heat is extracted from the cooler inside air and rejected to the warmer outdoor air or other heat sink. For space conditioning of buildings, heat pumps that remove heat from outdoor air in the heating mode and reject it to outdoor air in the cooling mode are common. These are normally called air-source or air-to-air...

2846 System Design and Installation

More is becoming known about the design and installation of ground-source heat pumps. Design-day cooling and heating loads are determined through traditional design practices such as those documented by the American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE). Systems are also zoned using commonly accepted design practices. The key issue that makes ground-source heat pumps unique is the design of the ground-coupling system. Most operational problems with ground-source heat pumps

284 About The Technology

In 1999, an estimated 400,000 ground-source heat pumps were operating in residential and commercial ap plications, up from 100,000 in 1990. In 1985, it was estimated that only around 14,000 ground-source heat pump systems were installed in the United States. Annual sales of approximately 45,000 units were reported in 1997. With a projected annual growth rate of 10 , 120,000 new units would be installed in 2010, for a total of 1.5 million units in 2010 (Lund and Boyd 2000). In Europe, the estimated total number of installed ground-source heat pumps at the end of 1998 was 100,000 to 120,000 (Rybach and Sanner 2000). Nearly 10,000 ground-source heat pumps have been installed in U.S. Federal buildings, over 400 schools and thousands of low-income houses and apartments (ORNL SERDP, no date). Although ground-source heat pumps are used throughout the United States, the majority of new ground-source heat pump installations in the United States are in the southern and mid-western states (from...

Design and Installation Guides

McQuiston. 1985. Design Data Manual for Closed-Loop Ground-Coupled Heat Pump Systems. American Society of Heating, Refrigerating, and Air-Conditioning Engineers, Inc., Atlanta, Georgia. Caneta Research, Inc. 1995. Commercial Institutional Ground-Source Heat Pump Engineering Manual. American Society of Heating, Refrigerating, and Air-Conditioning Engineers, Inc., Atlanta, Georgia. international Ground-Source Heat Pump Association (not dated). Ground Source Systems Design and Installation Standards. Oklahoma State University, Stillwater, Oklahoma. *Oklahoma State University. 1988. Closed-Loop Ground-Source Heat Pump Systems Installation Guide. International Ground-Source Heat Pump Association, Stillwater, Oklahoma. *STS Consultants. 1989. Soil and Rock Classification for the Design of Ground-Coupled Heat Pump Systems Field Manual. CU-6600, Electric Power Research Institute, Palo Alto, California.

Hotair Engine Competitions

Coefficient of performance The ratio of heat transferred to input work. For a refrigerator the COP Meat lifted (refrigeration cffcct) Work supplied. For a heat pump the COP Meat rejected Work supplied (i.e. the inverse of thermal efficiency). Compression space The part of the working space in a Stirling engine where the working fluid is principally concentrated when the total system volume is decreased, the pressure rises, and heat is rejected to the cooling water. In a prime mover the compression space is cooler than the expansion space. In a refrigerator or heat pump the compression space is warmer than the expansion space. Displaccr A lightweight structural reciprocating element in a Stirling engine characterized by a large temperature difference but a negligible pressure difference between the upper arid lower transverse faces. Double-acting engines A family of Stirling engines having a single reciprocating element per thermodynamic system. There is a minimum number of two...

2854 Design and Equipment Integration

The purpose of this chapter is to familiarize the energy manager and facility engineer with the benefits and liabilities of ground-source heat pumps in their application to commercial buildings. It is beyond the scope of this chapter to fully explain the design requirements of a ground-source heat pump system. It is, however, important that the reader know the basic steps in the design process. The design of a ground-source heat pump system will generally follow the following sequence 4. Select the alternative HVAC system components, including the indoor air-distribution system type size the alternatives as required and select equipment that will meet the demands calculated in Step 2 (using the preliminary estimate of the entering water temperatures to determine the heat pump's heating and cooling capacities and efficiencies). Although the design procedure for the ground-coupling system is an iterative and sometimes difficult process, several sources are available to simplify the...

Localized Onsite Electric Power Generation vs Centralized Power Plant

In a limited range of applications, electric-drive heat pump technologies provide efficient transfer of heat from ambient or low-temperature sources to meet low-grade heating loads. Heat pumps are commonly used, for example, for space heating applications in areas subject to mild winter weather conditions.

Performance And Efficiency Terminology

Coefficient of Performance (COP) The COP is the basic parameter used to report the efficiency of refrigerant-based systems. It is a unitless term. This term is universal in its use but not in its meaning. COP can be used to define both cooling efficiency or heating efficiency, such as for a heat pump. For cooling, COP is defined as the ratio of the rate of heat removal to the rate of energy input to the compressor, in consistent units. For heating, COP is defined as the ratio of rate of heat delivered to the rate of energy input to the compressor, in consistent units. COP can be used to define the efficiency at a single (standard or nonstandard) rated condition or a weighted average (seasonal) condition. Depending on its use, the term may or may not include the energy consumption of auxiliary systems such as indoor or outdoor fans, chilled water pumps, or cooling tower systems. For purposes of comparison, the higher the COP the more efficient the system. For mathematical purposes, COP...

2847 Summary of Ground Loop Design Software

Because of the diversity in loads in multi-zone buildings, the design of the ground-coupling heat exchanger (the ground loop) must be based on peak block load rather than the installed capacity. This is of paramount importance because ground coupling is usually a major portion of the total ground-source heat pump system cost, and over-sizing will render a project economically unattractive. buildings will have significantly more heat rejection than extraction. This imbalance in heat rejection extraction can cause heat buildup in the ground to the point where heat pump performance is adversely affected and hence system efficiency and possibly occupant comfort suffer. (This is an important consideration in producintg accurate life-cycle cost estimates of energy use.) Proper design for commercial-scale systems almost always benefits from the use of design software. Software for commercial-scale ground-source heat pump system design should consider the interaction of adjacent loops and...

Vapor Degreasing Equipment

All vapor degreaser designs provide for an inventory of solvent, a heating system to boil the solvent, and a condenser system to prevent loss of solvent vapors and control the upper level of the vapor zone within the equipment. Heating the degreaser is usually accomplished by steam. However, electrical resistance (< 3.0 W cm2 or < 20 W in.2) heaters, gas combustion tubes, and hot water can be used. Gas combustion heaters with open flames located below the vapor degreaser are not recommended and are prohibited by OSHA regulations. Specialized degreasers are designed to use a heat pump principle for both heating and vapor condensation. In this instance, the compressed gases from the heat pump are used for heating the vapor degreasing solvent, and the expanded refrigeration gases are used for vapor condensation. Such a degreaser offers mobility that permits movement without having to be connected to water, steam, or gas for operation.

286 Technology Performance

In 1999, an estimated 400,000 ground-source heat pumps were operating in residential and commercial applications, up from 100,000 in 1990. With a projected annual growth rate of 10 , 120,000 new units would be installed in 2010, for a total of 1.5 million units in 2010 (Lund and Boyd 2000). The majority of new ground-source heat pump installations in the United States are for residential applications in the southern and mid-western states. Environmental concerns and a general lack of understanding of the technology by HVAC companies and installers have limited installations in the west. Observations about field performance of ground-source heat pumps obtained from federal and private-sector users are summarized in this section. The large numbers of reported installations testify to the stability of this technology. Most sites contacted report satisfaction with the overall performance (energy efficiency, maintenance, and comfort) of the technology. One of the world's largest...

Cooling Towers And Evaporative Condensers 37

A device closely related to the evaporative condenser is the evaporative cooler, where instead of condensing a refrigerant inside the tubes a liquid is cooled. One application for the evaporative cooler is the heat rejector in the decentralized heat pump described in Sec. 18-8.

Types of Heat Source and Heat Sink Media

Numerous heat sources and distribution fluids can be used with heat pumps and there are many variations on the basic system design. Following are brief descriptions of commonly used heat source and heat sink media. Outdoor air represents a virtually unlimited heat source and heat sink medium for heat pumps and is widely used in small-capacity systems. Other sources of air for heat pumps include air from internal spaces and air from process or HVAC exhaust systems. Since air is a relatively inefficient heat transfer medium, a large surface area is required for heat exchange coils. Since outside air temperature fluctuates so widely, set point design is a critical task. As the outdoor temperature decreases, heating capacity and efficiency of an air source heat pump decreases rapidly. Supplemental heating sources are generally required in colder climate regions. As outdoor air temperature increases, capacity and efficiency in cooling mode decreases. Air source heat pumps also require...

Example Applications

In Section 4.3.3 an example involving the evaluation of a baseboard heating and window air conditioner versus a heat pump was introduced to illustrate cash flow diagramming (Figure 4.2). A summary of the differential costs is repeat here for convenience. The heat pump costs 1500 more than the baseboard system, The heat pump saves 380 annually in electricity costs, The heat pump has a 50 higher annual maintenance costs, The heat pump has a 150 higher salvage value at the end of 15 years, The heat pump requires 200 more in replacement maintenance at the end of year 8. If MARR is 18 , is the additional investment in the heat pump attractive Decision PW> 0 ( 139.56> 0.0), therefore the additional investment for the heat pump is attractive.

289 Manufacturers

There are a number of manufacturers of ground-source heat pumps and water-source heat pump that can be ground coupled. The following is list of U.S. manufacturers identified on the Geothermal Heat Pump Consortium web site13. 13List obtained from the Geothermal Heat Pump Consortium, Inc. web site, (last accessed 1 November 2005). Air-Source Heat Pump Ground-Source Heat Pump

Case Studies

March 22, 1993. 120-ton geothermal system replaces 30-year-old relics. The Air Conditioning, Heating, and Refrigeration News. *Gahran, A. September 1993. Grants, Util. Rebate Pay 97 of Ground-Source Heat Pump Project Cost. Energy User News 18(9) pp. 10, 51, 72. *Gahran, A. January 1994. New Ground-Source Heat Pumps Cut Energy, Maintenance Costs 68K. Energy User News 19(1) p. 16. KCPL. 1994. Station's Ground Source Heat Pump System Finds Efficiency in Unusual Places. Commercial case study 4-118, Kansas City Power and Light, Kansas City, Missouri. PSO. Facility Type Family Fitness Center, Technology Application Ground- Source Heat Pump. Power Profile. Number 1, Public Service Company of Oklahoma, Tulsa, Oklahoma.

Heat Balance Control

Controlling the reheat valves from being nearly closed will eliminate unstable (cycling) valve operation. This also minimizes pumping costs by minimizing pressure losses through throttling valves and minimizes heat pump operating costs by minimizing the required hot water temperature.

Open Loop Systems

Open-loop systems use local groundwater or surface water (i.e., lakes) as a direct heat transfer medium instead of the heat transfer fluid described for the closed-loop systems. These systems are sometimes referred to specifically as ground-water-source heat pumps to distinguish them from other ground-source heat pumps. Open-loop systems consist primarily of extraction wells, extraction and reinjection wells, or surface water systems. These three types are illustrated in Figures 28.2e, 28.2f, and 28.2g, respectively. Disadvantages Subject to various local, state, and Federal clean water and surface water codes and regulations large water flow requirements water availability may be limited or not always available heat pump heat exchanger subject to suspended matter, corrosive agents, scaling, and bacterial contents typically subject to highest pumping power requirements pumping energy may be excessive if the pump is oversized or poorly controlled may Each of the ground-coupling systems...

N Vl2gc nozzle Vg2gc

The vapor compression cycle is almost a reversed Rankine cycle. The major difference is that a simple expansion valve is used to reduce the pressure between the condensor and the evaporator rather than being a work-producing device. The reliability of operation of the expansion valve is a valuable trade-off compared to the small amount of work that could be reclaimed. The vapor compression cycle can be used for refrigeration or heating (heat pump). In the energy conservation area, applications of the heat pump are taking on added emphasis. The device is useful for heating from an electrical source (compressor) in situations where direct combustion is not available. Additionally, the device can be used to upgrade the temperature level of waste heat recovered at a lower temperature.

Heat Sink

Peltier effect is the basis of the thermoelectric cooler (TEC), which is a semiconductor-based electronic component that functions as a small heat pump. This is basically a semiconductor p-n junction, and is operated by low-voltage DC power source, and could be used for heating and cooling just by reversing the flow of current direction. Typical TEC consists of two parallel plate ceramic, separated by the p and n type of materials, as shown in Fig. 12.31. The elements are connected with each other electrically in series, and thermally in parallel. When a positive DC current is applied to the n-type thermo element, electrons pass from the p to n type thermo element and the cold side temperature decreases as heat is absorbed. This heat is transferred to the hot side of the cooler, where it is dissipated into the heat sink and surrounding environment. The heat absorption (cooling) is proportional to the current and the number of thermoelectric couples. The thermoelectric semiconductor...

Pumps And Piping

7-2 Comparison of water and air as heat-conveying media The final transfer of heat is almost always either from or to the air in the conditioned space. The device for providing heat (heat source) is usually an electric or fuel-fired furnace, and the device for extracting heat (heat sink) is a refrigeration unit. When a heat pump is used, the same equipment is both the source and sink of energy. While the source or sink of heat may sometimes be located in the conditioned space, the typical situation is that the source and sink be remotely located from the conditioned space, so that either air or water is heated or cooled at the source or sink and cooled or heated, respectively, at the conditioned space, as shown schematically in Fig. 7-1. Air could be heated or cooled at the source or sink and delivered directly to the conditioned space, or water could be heated or cooled and subsequently heat or cool the air in the conditioned space.

Heavy force fit

Heat pipe eng A heat-transfer device consisting of a sealed metal tube with an inner lining of wicklike capillary material and a small amount of fluid in a partial vacuum heat is absorbed at one end by vaporization of the fluid and is released at the other end by condensation of the vapor. 'het .pTp heat pump mech eng A device which transfers heat from a cooler reservoir to a hotter one, expending mechanical energy in the process, especially when the main purpose is to heat the hot reservoir rather than refrigerate the cold one. 'heTt .psmp heat quantity thermo A measured amount of heat units are the small calorie, normal calorie, mean calorie, and large calorie. 'het kwSn-sd-eT

1212 Hardware

An EMCS can range from a very simple standalone unitary microprocessor based controller with firmware routines (control software logic that the user cannot modify except for setpoints) that provides control of a terminal unit such as a heat pump to a very sophisticated large building DDC EMCS that interfaces with fire and security systems. Although this chapter will generally cite examples from applications in medium to large facilities, there have been numerous documented successes with stand-alone controllers in small buildings. Fast food and dinner houses, auto dealerships, retail stores, bowling centers, super markets, branch banks, small commercial offices, etc., have all benefited from this technology. Typically, EMCS installations at small buildings are 'design build'. That is, an EMCS manufacturer, distributor, installing contractor, end user, or some combination thereof select the EMCS hardware and decides how it is to be applied.

Life Cycle Cost

The total installation cost for the ground-source heat pump option (including material, labor, overhead, and profit) is estimated to be 451,500, compared with the conventional system at 349,300 and the air-source heat pump system at 236,000. The operations and maintenance cost for the ground-source heat pump system is estimated to be 5,880 yr, compared with 6,750 yr for the conventional system and 4,725 yr for the air-source heat pump system. Through BLCC, the total life-cycle costs for the three alternatives were estimated to be 938,282 for the ground-source heat pump system, 800,065 for the air-source heat pump system, and 974,924 for the conventional system. A summary of the energy and cost factors and the results of the life-cycle cost analysis for each of the three options are shown in Table 28.11. The fact that the ground-source heat pump system did not have the lowest life-cycle cost in this evaluation should not imply that ground-source heat pumps are never cost effective in...

2853 What to Avoid

The following precautions should be followed when the application of ground-source heat pump technology is considered Avoid threaded plastic pipe connections in the ground loop. Specify thermal fusion welding. Unlike conventional water-source heat pump systems where the water loop temperature ranges from 60 to 90 F (15.6 to 32.2 C), ground-source systems are subject to wider temperature ranges (20 to 110 F -6.7 to 43.3 C ), and the resulting expansion and contraction may result in leaks at the threaded connection. It is also generally recommended to specify piping and joining methods approved by International Ground-Source Heat Pump Association (IGSHPA). Have the ground-source heat pump system installed as a complete and balanced assemblage of components, each of which must be properly designed, sized, and installed (Giddings 1988). Also, have the system installed under the responsibility of a single party. If the entire system is installed by three different professionals, none of...

Closedloop Systems

The loop is filled with a heat transfer fluid, typically water or a water-antifreeze5 solution, although other heat transfer fluids may be used.6 When cooling requirements cause the closed-loop liquid temperature to rise, heat is transferred to the cooler earth. Conversely, when heating requirements cause the closed-loop fluid temperature to drop, heat is absorbed from the warmer earth. Closed-loop systems use pumps to circulate the heat transfer fluid between the heat pump and the ground loop. Because the loops are closed and sealed, the heat pump heat exchanger is not subject to mineral buildup and there is no direct interaction (mixing) with groundwater.

875724

The heating cycle and again for the cooling cycle. During zero building load conditions, which occurs at the facility balance temperature, the entering water temperature is assumed to be equal to the ground temperature. During the peak load, the entering EWT is set to the maximum temperature desired during the peak cooling season load similarly, it is set to the minimum temperature desired during the peak heating season load. Publications by the International Ground-Source Heat Pump Association recommend for initial calculations these temperatures be set to 100 F maximum (37.8 C) and 37 F (2.8 C) minimum, although in this example, the minimum temperature was set to 35 F (1.7 C). Today, most commercial systems are commonly designed at 90 F (32.2 C) maximum EWT. The estimated entering water temperatures are refined later in the design process, as the ground-coupling system design is finalized. Column 5 in Table 28.3 is the net capacity of the ground-source heat pump equipment. This is...

2863 Maintenance

The ground-source heat pump technology is mature and reliable. Systems have standard warranties ranging from 1 to 5 years. The heat pump units are self-contained, and maintenance requirements are relatively straightforward no new maintenance skills are necessary. Because heat pump equipment is not exposed to outdoor elements, the units actually require less maintenance than typical air-source heat pumps. One site reported a problem with cottonwood trees clogging outside condenser units of the previous air-conditioning systems. This maintenance problem was eliminated with the application of ground-source heat pumps. 10Rating based on ANSI ARI ASHRAE ISO Standard 13256-1-2005 for closed-loop ground-source heat pumps. In open-loop systems, the well requires maintenance similar to any water well. The system should be routinely monitored for temperature, pressure, and flow. Because groundwater is being supplied to the heat pump, the heat exchangers should be routinely inspected for...

285 Application

This section addresses technical aspects of applying ground-source heat pumps. The range of applications and climates in which the technology has been installed are discussed. The advantages, limitations, and benefits are enumerated. Design and integration considerations for ground-source heat pumps are highlighted, including energy savings estimates, equipment warranties, relevant codes and standards, equipment and installation costs, and utility incentives. A ground-source heat pump system is one of the most efficient technologies available for heating and cooling. It can be applied in virtually any climate or building category. Although local site conditions may dictate the type of ground-coupling system employed, the high first cost and its impact on the overall life-cycle cost are typically the constraining factors. The operating efficiency of ground-source heat pumps is very dependent on the entering water temperature, which, in turn, depends on ground temperature, system load,...

Energy Requirements

The heat required to freeze water is about 80 cal g, whereas the heat required to vaporize is above 560 cal g. However, freezing processes do not require less energy than evaporative processes. All desalination processes are essentially heat-pumping processes, and the work requirement depends on the quantity of heat pumped and the temperature difference over which the heat is pumped. The work requirement for sea water desalination is about the same regardless of whether freezing or evaporation methods are used. The following equation describes a reversible heat pump

Other Sources

American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE). 1997. Ground Source Heat Pumps Design of Geothermal Systems for Commercial and Institutional Buildings. ASHRAE, Atlanta, GA. Cane, D., A. Morrison, and C. Ireland. 1998. Maintenance and Service Costs of Commercial Building Ground-Source Heat Pump Systems. ASHRAE Transactions, Vol 104(2) 699-706. Duffy, G. July August 1989. Commercial Earth-Coupled Heat Pumps Are Ready To Roll. Engineered Systems, pp. 40-47. *Geothermal Heat Pumps. February 1990. Custom Builder. 5(2) pp. 32-35. *Giddings, T. February 1988. Ground Water Heat Pumps Gilmore, V.E. June 1988. Neo-geo heat pump. Popular Science 232(6) pp. 88-89,112. *Heinonen, E.W., R.E. Tapscott, M.W. Wildin, and A.N. Beall. February 1997. Assessment of Antifreeze Solutions for Ground-Source Heat Pump Systems. Report 908RP, American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE), Atlanta. Hurlburt, S. February 1988. Ground Water...

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Summer Civil Pump

If the same energy input, Qs. were consumed in eleclric resistance heating or in a gas or oil furnace the heat available for heating would simply be Qs. Therefore, use of the heat pump has increased the heat available for heating to Qs+Qa- Depending on the conditions, the increase in effective heating available may range front 40 to 100 per cent. Of course the increase in effective heating has been gained at the expense of a considerable involvement in machinery. The capital cost of a heat pump system would inevitably be much greater than a simple furnace. As fuel costs increase, the economy of heat pumps is enhanced. Fortunately the same machinery used in the above heat pump for heating may also be deployed as the refrigerator cooling unit in an air conditioning system for summer use. F10. 19.4 Stirling-engine heat pump for summer cooling or winter heating. F10. 19.4 Stirling-engine heat pump for summer cooling or winter heating. STIKI-JNG RANKINE-CYCLE HEAT PUMPS Most development...

2842 Other benefits

The primary benefit of ground-source heat pumps is the increase in operating efficiency, which translates to a reduction in heating and cooling costs, but there are additional advantages. One notable benefit is that ground-source heat pumps, although electrically driven, are classified as a renewable-energy technology. The justification for this classification is that the ground acts as an effective collector of solar energy. The renewable-energy classification can affect federal goals and potential federal funding opportunities. An environmental benefit is that ground-source heat pumps typically use 25 less refrigerant than split-system air-source heat pumps or air-conditioning systems. Ground-source heat pumps generally do not require tampering with the refrigerant during installation. Systems are generally sealed at the factory, reducing the potential for leaking refrigerant in the field during assembly. Ground-source heat pumps also require less space than conventional heating and...

Example 146

For the concentration of fruit juice by evaporation it is proposed to use a falling-film evaporator and to incorporate a heat pump cycle with ammonia as the medium. The ammonia in vapour form will enter the evaporator at 312 K and the water will be evaporated from the juices at 287 K. The ammonia in the vapour-liquid mixture will enter the condenser at 278 K and the vapour will then pass to the compressor. It is estimated that the work for compressing the ammonia will be 150 kJ kg of ammonia and that 2.28 kg of ammonia will be cycled kg water evaporated. The following proposals are available for driving the compressor

281 Abstract

Ground-source heat pumps can provide an energy-efficient, cost-effective way to heat and cool commercial facilities. While ground-source heat pumps are well established in the residential sector, their application in larger, commercial-style, facilities is lagging, in part because of limited experience with the technology by those in decision-making positions. Through the use of a ground-coupling system, a conventional water-source heat pump design is transformed to a unique means of utilizing thermodynamic properties of earth and ground-water for efficient operation throughout the year in most climates. In essence, the ground (or groundwater) serves as a heat source during winter operation and a heat sink for summer cooling. Many varieties in design are available, so the technology can be adapted to almost any site. Ground-source heat pump systems can be used widely in commercial-building applications and, with proper installation, offer great potential for the commercial sector,...