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Bosch Geothermal Heat Pumps Applications Manual

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Bosch Geothermal Heat Pumps
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  • Page 1 Bosch Geothermal Heat Pumps For Residential Applications Applications Manual...
  • Page 2 Applications Manual 2 | Bosch Geothermal Heat Pumps Data subject to change Bosch Thermotechnology Corp.
  • Page 3: Bosch Geothermal Heat Pumps

    10.2 Piping Installation and Borehole Alignment 10.3 Loop Field Identi cation 4.2 Bosch Water-to-Water Heat Pumps 10.4 Location of Vertical Closed-Loops 4.3 Bosch Air Handling Unit for the Retro t Market 4.4 Bosch Water-to-Air Geothermal Heat Pump 10.5 Borehole Construction Operation 10.6 Typical Methods Used for Vertical Borehole...
  • Page 4: Table Of Contents

    Tankless Water Heating Integrated Systems 18.3 Bosch Geothermal Water-to-Water Heat Pump and Condensing Gas Boiler Integrated System 19 Bosch Complete - Net Zero Energy Home 19.1 Bosch Experience Center at Serenbe (BECS) Projects Data subject to change Bosch Thermotechnology Corp.
  • Page 5: Explanation Of Symbols

    Applications Manual Bosch Geothermal Heat Pumps | 5 1 Explanation of symbols WARNING: Follow each appliances' instructions precisely. Warnings For assistance or further information, contact a trained and certi ed installer, service provider, or the gas licensed plumber or gas tter.
  • Page 6 There are a wide variety of techniques, practices and strategies possible when installing geothermal heat pumps. It is the responsibility of the installing contractor to determine the best solution for the particular geothermal heat pump system application.
  • Page 7: System Applications

    And, geothermal heat pump systems are becoming more “price-competitive” with conventional conditioning systems. A Bosch geothermal heat pump system (Fig. 1) will consist of a Bosch geothermal heat pump coupled with a ground heat exchanger to reject or add heat to the structure as necessary.
  • Page 8 These components comprise the basic geothermal heat pump refrigerant circuit to transfer heat to and from the ground to the home (Fig. 3,4,5). All Bosch geothermal heat pump units are designed for HFC-410A refrigerant.
  • Page 9: Bosch Self-Contained (Package) And Split System Water-To-Air Heat Pumps

    Bosch Geothermal Heat Pumps | 9 4.1 Bosch Self-Contained (Package) and Split- System Water-to-Air Heat Pumps Bosch has a variety of choices for self-contained residential geothermal heat pumps. Multiple air ow con gurations for most any installation are also available.
  • Page 10 For greater performance, Bosch offers an Energy Star The most popular self-contained residential water-to-air rated water-to-air geothermal ready heat pump equipped geothermal heat pumps are the Bosch Premium two-stage with a two-stage compressor and a variety of superior series geothermal heat pumps, compliant with Energy standard features (Fig.
  • Page 11: Bosch Water-To-Water Heat Pumps

    Applications Manual Bosch Geothermal Heat Pumps | 11 4.2 Bosch Water-to-Water Heat Pumps Bosch’s Energy Star rated geothermal ready water-to-water heat pump gives the customer both geothermal heating and cooling as well as the ability to enjoy the bene ts of warm radiant oors.
  • Page 12: Bosch Air Handling Unit For The Retro T Market

    Fig. 12 Air handling unit for retro t market Plenum collar on supply outlet The Bosch Air Handling Unit is a single piece air handler providing the exibility for installation in any up ow, down ow, or horizontal application. These versatile models may be used with or without electric or hot water heat.
  • Page 13: Bosch Water-To-Air Geothermal Heat Pump Operation

    Applications Manual Bosch Geothermal Heat Pumps | 13 4.4 Bosch Water-to-Air Geothermal Heat Pump Operation 4.4.1 Heating Cycle In the heating cycle, the groundwater, or groundwater and In the compressor, the refrigerant rises in temperature. antifreeze mixture, circulating in the earth loop is colder From the compressor, the reversing valve sends the now- than the surrounding ground.
  • Page 14 The refrigerant, which has released its heat energy and Unlike air-source heat pumps, geothermal heat pumps do became a cold liquid, now, travels to the refrigerant-to- not require a defrost cycle. Temperatures underground air heat exchanger.
  • Page 15: Bosch Water-To-Air Geothermal Heat Pump Ratings

    Unfortunately, the ratings used for different types of equipment (furnaces, air-source heat pumps, geothermal heat pumps) are not generally consistent making comparisons dif cult. As a result, it is useful to know what the ratings values include and what they don't.
  • Page 16 Fig. 15 Certi cation logos Today, all manufacturers, including Bosch, have their water-to-air geothermal heat pumps tested and certi ed by a combination of the Air Conditioning, Heating, and Refrigeration Institute (AHRI) for their cooling capacities and their operating ef ciencies, and the ISO 13256-1 standards (Fig.
  • Page 17: Bosch Geothermal Heat Pump Equipment Sizing

    The sizing of the circulation pumps, the distribution system and the ground heat exchanger, or “ground loop” are all derived directly from the sizing of the Bosch geothermal heat pump equipment. Overestimating the heat loss or heat gain means over-sizing the system. The extra cost of the oversized system is unnecessary.
  • Page 18 50°F water year around, but a “Closed- Loop” system in Texas may see temperatures ranging from 60°F to 95°F, which will have an effect on the capacity of the Bosch geothermal heat pump in both the heating and cooling modes. Data subject to change...
  • Page 19 99% design condition, and the cooling design temperature is referred to as If a Bosch geothermal heat pump equipped with a single the 1% (or 2.5%) design condition. Either way, the load stage compressor is sized for the full heating loss load...
  • Page 20 EWT/EFT (for mild and warm climates). As a guide, for geothermal heat pumps in warm climates, generally good design is to select equipment that is within In most areas of the U.S., Bosch geothermal heat 15%-20% of the calculated cooling load.
  • Page 21 Per Manual S, 25% larger than the total cooling load associated Bosch data (Table 3). As a the Bosch two (2) = 1.25 x 32,000 Btu/h = 40,000 Btu/h ton geothermal heat pump is too small, we must examine...
  • Page 22 Applications Manual 2 2 | Bosch Geothermal Heat Pumps We nd that when looking at the Bosch three (3) ton geothermal heat pump system cooling capacity at full load, we see that at an Entering Fluid Temperature of 50°F (the typical shallow groundwater temperature for the location is 47°F per Bosch Geo Solutions software)
  • Page 23 Examining the part load speci cations (Table 4) for the Bosch three (3) ton geothermal heat pump unit at 50°F EFT (the typical shallow groundwater temperature for the location is 47°F per Bosch Geo Solutions software), we nd that at 75°Fdb, 63°Fwb Entering Air Temperature...
  • Page 24 -11°F. Examining the actual bin hours for Minneapolis, the approximate heating ability of the Bosch three MN (see Table 5), we nd that the Bosch three (3) ton (3) ton geothermal heat pump as well from published geothermal heat pump providing compressor heating will speci cations (Table 7).
  • Page 25 We will therefore examine the abilities in the heating mode. The installer can determine the of a four (4) ton Bosch geothermal heat pump unit in this capacity of the Bosch three (3) ton geothermal heat pump colder climate application next.
  • Page 26 2 6 | Bosch Geothermal Heat Pumps Example 2: Example 2: In this example, we will examine the Bosch four (4) ton Heating Dominate Climate geothermal heat pump unit as the possible selection for this application. Our goal is to provide more heating...
  • Page 27 Applications Manual Bosch Geothermal Heat Pumps | 27 Capacity Data - Full Load Cooling - all performance at 1700 CFM and 12.0 GPM Entering Fluid Entering Air Total Capacity Sensible Capacity Sensible to Power Input Heat of Reject Temp. (ÝF) Temp.
  • Page 28 65,000 Btu/h at -11°F outdoor 54.04 3.20 43.13 temperature. We will be able to meet approximately 70% 58.15 3.29 46.94 of the structure heat loss with the Bosch four (4) ton geothermal heat pump capacity at design conditions. 42.72 3.08 32.21 46.55 3.17 35.73 Examining the actual bin hours for Minneapolis, MN using 50.39...
  • Page 29 We will be able to meet approximately 53% to adequately provide emergency heating if necessary. of the structure total heat loss with the Bosch four (4) ton The size of heater should typically meet 90% of the heat geothermal heat pump unit capacity if it was operating loss of the structure minimum (58,500 Btu/h) at design at design conditions.
  • Page 30 Tab. 16 (Antifreeze required) (EFT Range (Standard) 25ÝF to 80ÝF) In this example, a Bosch four (4) ton geothermal heat pump unit with a two-stage compressor was selected. This application is acceptable and the heating needs in the colder climate may require the use of auxiliary heat below...
  • Page 31 Bosch Geothermal Heat Pumps | 31 Example 3: Example 3: In this example, we will examine the Bosch four (4) ton Cooling Dominate Climate geothermal heat pump unit as the possible selection for this application. Our goal is to provide the required cooling...
  • Page 32 The bin hours of temperatures between 75ºF will allow humidity removal and still meet the structure and 95ºF for the location with the Bosch four (4) ton heat gain. If the outdoor temperature exceeds the actual geothermal heat pump installed (per Bosch Geo Solutions cooling design temperature of 98°F, the four (4) ton...
  • Page 33 (86% of total capacity). This leaves 5,270 Btu/h latent capacity. During milder summer days, this Bosch four (4) ton geothermal heat pump will run in part load and still provide the necessary cooling needs for the structure. This operation mode will require less...
  • Page 34 Bosch four (4) ton geothermal heat pump capacity at design conditions. Examining the actual bin hours for Dallas, TX using the Bosch four (4) ton geothermal heat pump (see Figure 34), we nd that the heat pump providing compressor heating will operate until the structure balance point of approximately 7°F...
  • Page 35: Ground Heat Exchanger Types

    Applications Manual Bosch Geothermal Heat Pumps | 35 5 Ground Heat Exchanger Types The two most prevalent types of residential geothermal also possible to the surface where allowed. Ponds and/or lakes are often used for this type of system as well.
  • Page 36: Open-Loop Geothermal Heat Pump Systems

    (Fig. equipment is required if clogged. If the Bosch geothermal 20). Local environmental of cials should be consulted heat pump is equipped with the optional Heat Recovery whenever an open-loop geothermal heat pump system is Package (“desuperheater”) its coil can become scaled and...
  • Page 37: Open-Loop Geothermal Heat Pump System Water Quantity

    1.5 GPM when water temperature is above 50ºF water requirement of a speci c model is usually expressed in Gallons per Minute (GPM) and is listed in the Bosch 2.0 GPM when water temperature is below 49 ºF speci cations for that unit. The groundwater well should...
  • Page 38: Open-Loop Geothermal Heat Pump System Water Quality

    Bosch geothermal heat pump. In conditions anticipating moderate scale formation or in brackish water a cupro-nickel water-to-refrigerant coaxial heat exchanger is recommended.
  • Page 39 Applications Manual Bosch Geothermal Heat Pumps | 39 Table 21 is indicative of typical water quality requirements for open-loop geothermal heat pump systems. Water Quality Requirements for Open-Loop Geothermal Heat Pump Systems Water Quality Parameter HX Material Closed Recirculating Open Loop and Recirculating Well Scaling Potential - Primary Measurement Above the given limits, scaling is likely to occur.
  • Page 40 Applications Manual 4 0 | Bosch Geothermal Heat Pumps Scaling potential should be assessed using the pH/ In Bosch open-loop geothermal heat pump system Calcium hardness method. If the pH <7.5 and the calcium applications, water pressure must always be maintained hardness is less than 100 PPM, scaling potential is low.
  • Page 41 24 VAC coil and be connected across Y1 and (return) well, the installer may prefer surface or near C1 on the interface board for all Bosch equipment. Assure surface disposal methods. However, many situations will that the VA draw of the solenoid valve, if used, does not not allow these methods.
  • Page 42 If a return well is used, it must be able to handle the To push water back into the ground aquifer, the pressure volume of water that passes through the Bosch geothermal on the column of water must be greater than the pressure heat pump (Fig.
  • Page 43: Water Well Criteria And Terminology

    Applications Manual Bosch Geothermal Heat Pumps | 43 Open-Loop Geothermal Heat Pump water level. If the water must be pumped from greater depths then pumping power per unit of water produced is System Design increased. The design of an open-loop system must consider...
  • Page 44: Groundwater Well Pumps

    Applications Manual 4 4 | Bosch Geothermal Heat Pumps test of the well. This data normally includes pumping water well serving the system (preferred) or from information on level at 3 different ow rates and the pre-test static water nearby wells. Also included in the lift is the friction loss level.
  • Page 45: Geothermal Standing Column System

    Applications Manual Bosch Geothermal Heat Pumps | 45 6.7 Geothermal Standing Column System A standing column well bridges the gap between an open- loop and a closed-loop geothermal heat pump system (Fig. 29). This type of system is simply a vertical re- circulating water- lled bedrock borehole.
  • Page 46: Closed-Loop Geothermal Heat Pump Systems

    Applications Manual 4 6 | Bosch Geothermal Heat Pumps 7 Closed-Loop Geothermal Heat Pump Systems Closed-loop ground heat exchanger systems have been used since the late 1970s and have become the most common system in residential geothermal heat pump markets. These ground heat exchangers are commonly installed in one of three con gurations: vertical closed- loop ground heat exchangers (“vertical loops”), horizontal...
  • Page 47: Ground Heat Source Or Heat Sink For Closed-Loop Ground Heat Exchangers

    An important sizing consideration is that the performance of the Bosch geothermal heat pump depends on the performance of the ground heat exchanger, or “ground loop”, and vice versa. It is therefore essential to design and size them together.
  • Page 48: Closed-Loop Ground Heat Exchanger Design Considerations

    Applications Manual 4 8 | Bosch Geothermal Heat Pumps 9 Closed-Loop Ground Heat Exchanger Design Considerations 9.1 Series or Parallel Con gurations Typically, closed-loop ground heat exchangers are arranged in either a series or parallel con guration (Fig. 33, 34).
  • Page 49: Ground Characteristics

    Bosch geothermal heat pump system (Fig. 35). Fig. 36 Ground temperature annual variation Courtesy of American Society of Heating, Air-conditioning and Refrigeration Engineers Inc., www.ashrae.org...
  • Page 50 Applications Manual 5 0 | Bosch Geothermal Heat Pumps Clay soils tend to hold water very well and the water content and thermal conductivity will not vary much over time. Good ground heat exchanger design involves selecting the lowest soil thermal conductivity expected for the particular soil type and installation location.
  • Page 51 Applications Manual Bosch Geothermal Heat Pumps | 51 Most soil is a combination of ne and coarse grain (Table 23). A sieve analysis can be used to determine the percentage of each so that a weighted average can be developed to nd an overall conductivity. Moisture content is a major factor, but sand or clay never needs to be heavily saturated to provide good conductivity.
  • Page 52 Applications Manual 5 2 | Bosch Geothermal Heat Pumps When discussing pipe properties, typical thermal resistances for four common pipe sizes can be considered (although 1-½" pipe is now becoming more dif cult to nd) (Table 25). Avoiding laminar ow at design conditions is important to provide good heat transfer.
  • Page 53: Closed-Loop Design Fundamentals

    Applications Manual Bosch Geothermal Heat Pumps | 53 9.4 Closed-Loop Design Fundamentals The closed-loop ground heat exchanger is similar to a cooling coil (or an evaporator) in a simple air conditioning (cooling only) system or air-source heat pump during cooling, absorbing heat from the structure to be rejected outside.
  • Page 54: Soil & Groundwater Temperature

    Applications Manual 5 4 | Bosch Geothermal Heat Pumps 9.5 Soil & Groundwater Temperature and cooling. Even if soil temperatures rise to 90°F during the summer or even 50°F during the winter, these systems The average soil/groundwater temperature of the upper can still utilize the 90°F soil temperature to provide...
  • Page 55: Piping

    9.6 Piping HDPE is suitable for use as the buried ground heat exchanger for a Bosch geothermal heat pump system. This Piping should be as speci ed in the International Ground piping is typically joined by heat fusion for all Iron Pipe Source Heat Pump Association (IGSHPA) standards for Size (IPS) dimensions.
  • Page 56: Pipe Fusion Methods

    Applications Manual 5 6 | Bosch Geothermal Heat Pumps 9.7 Pipe Fusion Methods Socket fusion joins two ends of pipe by fusing each pipe end to a socket tting. This requires two heat fusion procedures for each joint. This method requires the...
  • Page 57 Applications Manual Bosch Geothermal Heat Pumps | 57 Fig. 47 Butt fusion visual inspection Fig. 45 Socket fusion joint inspection Sidewall butt fusion joining is used when joining the Butt fusion is the joining procedure where two pipe ends concave surface of a service saddle to the convex surface are simultaneously heated to a plastic state by a heater on the sidewall of a pipe (Figure 71).
  • Page 58: Heat Transfer Fluids (Antifreeze)

    Applications Manual 5 8 | Bosch Geothermal Heat Pumps HDPE pipe is heat fused and joined using both socket and 9.8 Heat Transfer Fluids (Antifreeze) butt fusion procedures. Material, grade, density and other In areas where minimum entering loop temperatures can variables help determine if the particular grade of pipe can be fused with either method.
  • Page 59 It has also been known to form “slime-type” coatings A potential negative effect of all geothermal heat pumps inside geothermal piping. Installers should always use is the release of antifreeze solutions to the environment.
  • Page 60: Closed-Loop Con Guration

    Applications Manual 6 0 | Bosch Geothermal Heat Pumps 9.9 Closed-Loop Con guration Fluid Volume (gal [L] / 100' Pipe) Pipe Size Volume (gal) [L] An installer must use good judgment and knowledge when determining the type of ground heat exchanger to install.
  • Page 61: Underground Piping Installation Criteria

    Applications Manual Bosch Geothermal Heat Pumps | 61 9.10 Underground Piping Installation Criteria Special attention should be paid to avoid sharp bends in piping and remove sharp-edged rocks or other material Piping, ttings and joints must be compatible with the in the trench back ll.
  • Page 62: Closed-Loop Header Design

    Applications Manual 6 2 | Bosch Geothermal Heat Pumps 9.11 Closed-Loop Header Design A closed-loop header is simply a series of larger diameter horizontal pipes that connects the geothermal ow center to each of the smaller diameter circuits located within each borehole.
  • Page 63 Applications Manual Bosch Geothermal Heat Pumps | 63 To determine the ushing requirements for any ground heat exchanger using the header styles shown, multiply the number of circuits by the ushing ow rate of each circuit. Header layouts are more cost effective with short headers.
  • Page 64 Applications Manual 6 4 | Bosch Geothermal Heat Pumps 10 Vertical Closed-Loop Ground Heat Exchangers (Vertical Loops) Many installers prefer vertical loops as ground surface With vertical loops the heat exchange takes place along requirements for them are much lower than horizontal the vertical drilled borehole walls.
  • Page 65: Groundwater Effects

    Bosch geothermal heat pump unit. Vertical loops are changes in the subsurface. Subsurface thermal changes generally more expensive to install, but require less piping can negatively impact the ef ciency of the system.
  • Page 66: Piping Installation And Borehole Alignment

    Applications Manual 6 6 | Bosch Geothermal Heat Pumps Generally, header layouts are more cost effective with 10.2 Piping Installation and Borehole short headers. This requires centrally locating the header Alignment to all circuits and then bringing the circuits to the header.
  • Page 67 Applications Manual Bosch Geothermal Heat Pumps | 67 Fig. 57 Courtesy of International Ground Source Heat Pump Association/Oklahoma State University Fig. 58 Courtesy of International Ground Source Heat Pump Association/Oklahoma State University Bosch Thermotechnology Corp. Data subject to change...
  • Page 68: Loop Field Identi Cation

    Applications Manual 6 8 | Bosch Geothermal Heat Pumps 10.3 Loop Field Identi cation Because the loop eld will be buried and out of sight, it is important to identify the location of the boreholes in case header repairs are needed or excavation work needs to be performed.
  • Page 69: Location Of Vertical Closed-Loops

    Applications Manual Bosch Geothermal Heat Pumps | 69 10.4 Location of Vertical Closed-Loops The following minimum horizontal separation distances typically should be maintained when installing a vertical (or horizontal) closed-loop ground heat exchangers (Fig. 61, 62): 50 feet from a household drinking water well...
  • Page 70: Borehole Construction

    Applications Manual 7 0 | Bosch Geothermal Heat Pumps 10.5 Borehole Construction If mineshafts, fractures or caverns are encountered in consolidated material, the borehole should be packed or Prior to borehole construction, the installer should always sealed above and below the void. Other methods may be locate and mark all existing underground utilities, piping, used as necessary to preserve borehole stability.
  • Page 71: Typical Methods Used For Vertical Borehole Construction

    Applications Manual Bosch Geothermal Heat Pumps | 71 10.6 Typical Methods Used for Vertical Borehole Construction 10.6.1 Air Rotary Drilling Air Rotary Drilling is used to construct vertical boreholes in rock formations (Fig. 63). High pressure, high volume compressed air is forced down the drill string to ush cuttings out of the borehole.
  • Page 72: Vertical Borehole Back Ll

    Applications Manual 7 2 | Bosch Geothermal Heat Pumps 10.7 Vertical Borehole Back ll Back ll plays a major part in performance when discussing minimized to limit the grout’s effect. Thermal resistance vertical boreholes. Air gaps or separation should be adjustments for other borehole back lls or grouts are avoided as air is a natural insulator.
  • Page 73: Proper Grouting

    Applications Manual Bosch Geothermal Heat Pumps | 73 10.8 Proper Grouting The “approved” method of grouting a vertical borehole is called “Tremie” grouting. It is sometimes also referred to as pressure grouting. Once the vertical loop has been installed into the borehole, another hose must be run down to the bottom of the borehole.
  • Page 74: Vertical Closed-Loop Grouting Recommendations

    Applications Manual 7 4 | Bosch Geothermal Heat Pumps 10.9 Vertical Closed-Loop Grouting 10.10 Grout Material Recommendations Grout material is typically used to ensure contact between the inserted pipe and the earth and helps promote heat The borehole should be grouted immediately after pipe transfer (Fig.
  • Page 75: Grouting Procedures

    Applications Manual Bosch Geothermal Heat Pumps | 75 10.11 Grouting Procedures Grouting is a highly variable operation in which many things can go wrong. Many factors can affect the behavior of the grout including components, ratios, temperature, chemical compositions of the water and bentonite, pH, etc.
  • Page 76: Ground Heat Exchangers

    The trenches are then back lled, ensuring that no sharp rocks or debris are present to damage the pipes. When retro tting a home with a Bosch geothermal heat pump system, a horizontal loop installation may pose more problems because landscaping will have already been completed.
  • Page 77: Horizontal - Loop Layout

    Applications Manual Bosch Geothermal Heat Pumps | 77 Another type of horizontal con guration is called the 11.1 Horizontal - Loop Layout “Slinky™” loop (Fig. 73). While this horizontal loop will The deeper a horizontal ground loop the more stable the require less land area, it will generally require more pipe than a parallel type horizontal loop con guration.
  • Page 78 (Fig. 78). joints), to ensure leak-free connections for the life of the piping. Other piping materials also exist and must be approved by IGSHPA for use with Bosch geothermal heat pumps. Properly installed, these pipes will last anywhere from 25 to 75 years.
  • Page 79 Applications Manual Bosch Geothermal Heat Pumps | 79 Two pipes in the same trench, one above the other, separated by approximately 2 feet of earth requires a trench typically 60% as long as a single pipe trench. The total length of pipe would be approximately 120% as long as a single pipe.
  • Page 80 Pipe depths in the Northern Zone should be 3 to 5 feet, as excessive depth will reduce the ability of the sun to recharge the heat used in winter. The Bosch Geo Solutions software program will help determine the appropriate depth for these applications.
  • Page 81: Trench Safety

    Applications Manual Bosch Geothermal Heat Pumps | 81 11.2 Trench Safety DANGER: No person should enter any trench excavated for a ground loop installation that is at a depth of 5 feet or greater. The Occupational Safety & Health Administration (OSHA) requires cave-in protection for anyone in any excavation 5 feet deep or more.
  • Page 82 Applications Manual 8 2 | Bosch Geothermal Heat Pumps 11.3 “Slinky™” Ground Heat Exchangers A variation of the horizontal ground heat exchanger often used today is the “Slinky™” loop horizontal closed-loop system (Fig. 85). This arrangement ties the pipe into large coils that overlap each other, allowing for large lengths of pipe to t into much smaller trenches.
  • Page 83: Racetrack Closed-Loop Ground Heat Exchangers

    Applications Manual Bosch Geothermal Heat Pumps | 83 11.4 Racetrack Closed-Loop Ground Heat Exchangers Another type of horizontal closed-loop application that is popular in moderate to colder climates is the “racetrack” loop (Fig. 89, 90). Typically, all of the pipes used and installed are at the same elevation in a much larger trench, or even a large pit area (Fig.
  • Page 84: Horizontal Directional Drilling (Hdd)

    Applications Manual 8 4 | Bosch Geothermal Heat Pumps 11.5 Horizontal Directional Drilling (HDD) Closed-Loop Ground Heat Exchangers Horizontal bore loops are becoming increasingly more popular today for new geothermal ground heat exchanger installations, especially when customers are concerned about landscaping and excavation (Fig. 92). Typically...
  • Page 85: Pond And Lake Geothermal Applications

    Applications Manual Bosch Geothermal Heat Pumps | 85 11.6 Pond and Lake Geothermal Applications coils are submerged. The piping and/or coils are placed in and anchored at approximately an 8 to 10 foot depth Pond or lake geothermal applications typically involve in the body of water.
  • Page 86 Applications Manual 8 6 | Bosch Geothermal Heat Pumps Fig. 94 "Slinky™" matt style Fig. 95 Data subject to change Bosch Thermotechnology Corp.
  • Page 87 Proper loop design as well as pond size and depth position in the body of water. The uid from the Bosch requirements are speci c to each application beginning geothermal heat pump must enter the lowest connection...
  • Page 88: Residential Structure Pipe Entry/Exit

    Applications Manual 8 8 | Bosch Geothermal Heat Pumps 12 Residential Structure Pipe Entry/Exit The entry and exit points from a residential structure should be watertight and constructed to prevent leaks (Fig. 98). Piping sleeves should be used at all entry and exit points.
  • Page 89 Applications Manual Bosch Geothermal Heat Pumps | 89 Fig. 101 Courtesy of International Ground Source Heat Pump Association/Oklahoma State University With below grade situations, always bring the pipe through the wall as indicated (Figure 102). If the ground heat exchanger could be subject to freezing, always insulate the piping at least 4 feet into the trench.
  • Page 90: Interior Piping

    9 0 | Bosch Geothermal Heat Pumps 13 Interior Piping Inside the home, the piping from the open-loop or closed- loop system will be connected to the Bosch geothermal heat pump. A typical piping layout is shown for both applications (Fig. 103, 104). Polyethylene pipe provides an excellent no leak piping material.
  • Page 91 Applications Manual Bosch Geothermal Heat Pumps | 91 Fig. 103 Fig. 104 Bosch Thermotechnology Corp. Data subject to change...
  • Page 92: Ground Loop Pumping Package (Glp)

    Applications Manual 9 2 | Bosch Geothermal Heat Pumps 14 Ground Loop Pumping Package (GLP) However, the thermal expansion of ground loop piping may 14.1 Flow Centers for Closed-Loop Ground cause the circulating pump or pumps to cavitate without Heat Exchangers the use of an expansion tank.
  • Page 93: Non-Pressurized Flow Centers

    Applications Manual Bosch Geothermal Heat Pumps | 93 14.3 Non-Pressurized Flow Centers Non-pressurized ow centers (Fig. 107) are simply canisters that hold uid on the suction side of circulating pumps (one, two or three) and include built-in pump protection which eliminates the need for a “ ush cart”...
  • Page 94: General Flow Center Criteria

    Bosch geothermal heat pump and the ground heat exchanger. Additionally, the ow center should be located as closed to the Bosch geothermal heat pump unit as possible to limit the length of hoses and associated pressure drop. Ease of future service should always be considered as well when determining ow center placement.
  • Page 95: Closed-Loop Flushing And Purging

    Fig. 112 Flush cart step 2 port/unit position. Make sure the water level is maintained while lling the Bosch geothermal unit. Flush the Bosch geothermal unit until all debris is removed and then return the 3-way valve to the ush port/loop position.
  • Page 96 Applications Manual 9 6 | Bosch Geothermal Heat Pumps Once all debris is removed make sure the return hose is below the reservoir water level. Continue running the ush cart pump while observing any air bubbles in the reservoir (Figure 113). “Dead head” the pump...
  • Page 97 (not required for “Taco” circulators). Always insure that the ow center provides adequate ow through the Bosch geothermal heat pump by checking the pressure drop across the heat exchanger and comparing it to the pressure drop tables in the Installation and Maintenance Manual for the particular Bosch geothermal heat pump.
  • Page 98: Bosch Geothermal Water-To-Water Heat Pump Applications

    Fig. 116 Water-to-water heat pump source liquid temperature between 25°F and 110°F. Bosch water-to-water geothermal heat pumps can be used 16.1 Bosch Geothermal Water-to-Water Heat with most geothermal sources (open and closed systems).
  • Page 99: Bosch Geothermal Water-To-Water Heat

    Like Bosch water-to-air heat pumps, Coaxial heat exchangers are not as susceptible to clogging economics must be considered for Bosch water-to-water and freezing as are plate heat exchangers. All Bosch water- applications. to-water geothermal units come standard with wrapped insulated coaxial heat exchangers.
  • Page 100: Pump And Radiant Floor Heating

    Applications Manual 1 0 0 | Bosch Geothermal Heat Pumps application is using existing fan coils for heating, especially those previously sized for high water temperatures. A room-by-room calculation should always be performed for all radiant oor system in order to determine the design of the radiation system.
  • Page 101: Pumps And Fan Coil Units/Air Handlers

    Chilled water is circulated through the coil if cooling is needed. Depending upon the application, Bosch water-to-water geothermal heat pumps can also be the unit will include one coil for both heating and cooling used with a fan coil(s) (air handler) to heat or cool air in...
  • Page 102: Pump Buffer Tank Application

    Bosch geothermal water-to-water heat pump is typically more than 20% larger than the cooling load and/or multiple fan coil units are to be used. Bosch TW Series geothermal water-to-water heat pumps sized for the cooling load in applications with only a single fan...
  • Page 103: Pump Piping Design

    3 tons with a maximum of 25 ft. one way In conditions anticipating moderate scale formation and 8 elbows. Larger 1" tubing should be used on Bosch or in brackish water a cupronickel heat exchanger is geothermal water-to-water heat pumps up to 6 tons with a recommended.
  • Page 104: Pump Sequence Of Operation

    Applications Manual 1 0 4 | Bosch Geothermal Heat Pumps Fig. 123 16.7 Bosch Geothermal Water-to-Water Heat Pump Sequence of Operation Cooling Mode Energizing the “O” terminal energizes the unit reversing valve in the cooling mode. When the thermostat calls for cooling (Y), the loop pump or solenoid valve if present is energized and the compressor will start.
  • Page 105: Pump Piping System Installation

    Applications Manual Bosch Geothermal Heat Pumps | 105 16.8 Bosch Geothermal Water-to-Water Heat leaks. When a thread by sweat (soldered) transition tting is used, always make the soldered connection rst, and Pump Piping System Installation then make the threaded tting using proper sealants.
  • Page 106: Bosch Geothermal Heat Pump System Options

    Applications Manual 1 0 6 | Bosch Geothermal Heat Pumps 17 Bosch Geothermal Heat Pump System Options 17.1 Bosch Cupronickel Coaxial Heat Exchanger Cupronickel heat exchangers (Fig. 124) are recommended for open loop applications due to the increased resistance to build-up and corrosion, along with reduced wear caused by acid cleaning.
  • Page 107 Heat exchangers that rupture due with cold water until the water leaving the drain hose to freezing will void the HRP warranty as well as the Bosch is clear and free of sediment. Then close all valves and geothermal heat pump warranty.
  • Page 108: Bosch Hot Gas Reheat (Hgr)

    (the HRP pump should never run if the compressor is not point the rest of the cooling cycle is completed. There are running). Press the HRP switch on the face of the Bosch two (2) check valves to prevent refrigerant ow into the geothermal heat pump to the “On”...
  • Page 109 (the reheat mode always operates simultaneously with the cooling mode.) The best way to control geothermal heat pumps with hot gas reheat is the one which ts the application. Most other geothermal heat pump compatible thermostats in conjunction with a humidistat are acceptable for use.
  • Page 110: Emerson Comfort Alert™ Diagnostic Module

    Applications Manual 1 1 0 | Bosch Geothermal Heat Pumps 17.4 Emerson Comfort Alert™ Diagnostic Module Many geothermal heat pumps utilize a self-diagnostic device to assist in troubleshooting. The Comfort Alert diagnostics module (CADM) is a breakthrough innovation for troubleshooting heat pump and air conditioning system failures (Fig.
  • Page 111 Applications Manual Bosch Geothermal Heat Pumps | 111 17.4.1 CADM Flash Codes (Table 33) Troubleshooting Information Solution column may re ect a possible fault that may be one of, or a combination of causes and solutions. Check each cause and adopt “process of elimination”...
  • Page 112 The controller is programmed in the factory with software versions that suit the different application for the models offered by Bosch. User settings such as the time and schedules can be preprogrammed or also change Fig. 132 Direct Digital Control during the installation of the product.
  • Page 113 Applications Manual Bosch Geothermal Heat Pumps | 113 Two provided sensors must be installed in the blower housing and the condenser water coil respectively. Drill a pilot hole on blower assembly (Fig. 134) to secure the sensor with the provided screw and strap. It is recommended to use a 9/64”...
  • Page 114 Applications Manual 1 1 4 | Bosch Geothermal Heat Pumps Rout the wiring harness through the unit corner post and assure the wires are inside the unit electrical box. Terminate the DDC digital output wires on the unit terminal block according to the provided DDC wiring diagram.
  • Page 115 Applications Manual Bosch Geothermal Heat Pumps | 115 Terminate/mate the male terminals from the DDC harness with female terminals from the sensors (Fig. 140). The installer must refer to the DDC and unit wiring diagrams as the ultimate guide for electrical reference.
  • Page 116: Differential Pressure Switch

    Applications Manual 1 1 6 | Bosch Geothermal Heat Pumps 17.6 Differential Pressure Switch 17.8 Sound Package Speci c models of 208/230V Bosch geothermal heat Speci c models of 208/230V Bosch geothermal heat pumps may be equipped with a factory installed pumps may be equipped with a factory installed sound Differential Pressure Switch (DPS).
  • Page 117: Bosch Geothermal System Integration

    “Bosch Complete” product portfolio. Bosch geothermal heat pump products work alone or with our solar thermal water heating, tankless water heating and gas condensing boiler products as an integrated system to provide the opportunity to customize unique energy ef cient systems (Fig.
  • Page 118 Bosch solar thermal Bosch also provides peace of mind to customers with our water heating systems provide the fastest hydraulic 15-year limited residential heat exchanger warranty for all collector connection set on market today.
  • Page 119: And Solar Thermal Water Heating Integrated Systems

    “Solar-Geo Assist” Option The system depicted (Fig. 149) is a Bosch solar-assisted Once the DHW tank reaches its upper limit and solar water-to-air geothermal heat pump system. This system is energy is still available, the diverter valve then routes the ideal for northern heating dominated markets.
  • Page 120 Tankless Water Heater. temperature to the xtures, the water is diverted around the Bosch Tankless Water Heater. If the temperature of the When waste heat is not available or is not enough to stored hot water does not meet the necessary domestic...
  • Page 121: Pump And Condensing Gas Boiler

    This energy is stored in a buffer tank sized The system shown (Fig. 151) is a Bosch water-to- according to the size of the Bosch geothermal heat pump. water geothermal heat pump integrated with a Bosch The structure demands energy from the buffer tank condensing wall mounted boiler.
  • Page 122: Bosch Complete - Net Zero Energy Home

    Bosch 3-ton geothermal heat pump The rst Bosch Net Zero Home (Fig. 152) in the US system (Fig. 153) is installed in the home (TA035-1HZC). is at Serenbe, located at 10660 Serenbe Lane, and Designed and built domestically in Ft.
  • Page 123 Electronically Commutated Motor (ECM) that is the home will supply as much energy as it uses. The Bosch factory programmed to vary the air ow based on full or...
  • Page 124 Applications Manual 1 2 4 | Bosch Geothermal Heat Pumps The Bosch Net Zero Home is also out tted with Bosch technology counterparts currently on the market. home appliances, including an Axxis washer and dryer; The Bosch Experience Center offers functioning a 24-inch DLX Bar Handle dishwasher (BSHX55RL5UC);...
  • Page 125 162 Bosch Solar Thermal System Experience Center (Fig. 161). In addition to the initial Bosch Net Zero home at Serenbe, two (2) more new homes, equipped with Bosch products, are under construction — offering a cost-effective suite of sustainable technologies that will serve as a model for U.S.
  • Page 126 Applications Manual 1 2 6 | Bosch Geothermal Heat Pumps Data subject to change Bosch Thermotechnology Corp.
  • Page 127 Applications Manual Bosch Geothermal Heat Pumps | 127 Bosch Thermotechnology Corp. Data subject to change...
  • Page 128 United States and Canada Bosch Thermotechnology Corp. 50 Wentworth Avenue Londonderry, NH 03053 Tel: 603-552-1100 Fax: 603-965-7581 www.bosch-climate.us BTC 436001101 A / 01.2013...