INSTALLATION, OPERATION & MAINTENANCE MANUAL
HTV/HTD/HTH Series
Two-Stage
Geothermal Heat Pumps
2 to 6 Tons
Heat Controller, Inc. • 1900 Wellworth Ave. • Jackson, MI 49203 • (517)787-2100 • www.heatcontroller.com
Installation, Operation & Maintenance |
HTV/HTD/HTH SERIES |
Heat Controller, Inc. |
Model Breakdown
Model Nomenclature – Two Stage Geothermal Heat Pump
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HT |
0 2 4 |
Series
HT = Heat Controller Two Stage
Configuration
V = Vertical Up Flow
H = Horizontal
D = Vertical Down Flow
Unit Size
024
036
048
060
070
Revision Level
B = Efficiency Upgrade
C = Microchannel Air Coil on 036
Voltage
1 = 208-230/30/1
Controls
C = CXM
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Supply Air Flow & |
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Motor Configuration |
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Supply |
Configuration |
Motor |
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K |
Top |
HTV |
ECM |
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N |
Down |
HTD |
ECM |
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P |
Back |
HTH |
ECM |
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W |
Straight |
HTH |
ECM |
Return Air Flow Configuration
L = Left Return
R = Right Return
Heat Exchanger Options
A = Copper Water Coil, Coated Air Coil
J = Copro-Nickel Water Coil, Coated Air Coil
Water Circuit Options
1 = HWG w/Internal Pump
0 = None
Cabinet
0 = Residential
TABLE OF CONTENTS
Model Nomenclature .......................................... |
2 |
Blower Data...................................................... |
26 |
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Storage............................................................... |
4 |
CXM Controls ................................................... |
27 |
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Pre-Installation.................................................... |
4 |
Safety Features – CXM Control.................. |
28-30 |
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Horizontal Installation ......................................... |
5 |
Unit Commissioning |
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Field Conversion of Air Discharge ...................... |
7 |
And Operating Conditions ................................ |
31 |
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Duct System Installation..................................... |
8 |
Unit Start-Up and Operating Conditions........... |
32 |
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Condensate Piping Installation........................... |
8 |
Unit Start-Up Procedure ................................... |
32 |
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Vertical Installation........................................ |
9-10 |
Coax Pressure Drop Tables.............................. |
34 |
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Water Connection Installation........................... |
11 |
Unit Operating Conditions .......................... |
35-36 |
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Ground Loop Applications ........................... |
11-12 |
Performance Data ...................................... |
37-41 |
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Open Loop - Ground Water Systems ............... |
13 |
Preventive Maintenance................................... |
42 |
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Water Quality Standards .................................. |
15 |
Troubleshooting................................................ |
43 |
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Hot Water Generator .................................. |
16-18 |
CXM Process Flow Chart ................................. |
44 |
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Electrical - Line Voltage.............................. |
19-20 |
Functional & Performance |
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Electrical - Low Voltage Wiring |
21-22 |
Troubleshooting.......................................... |
45-46 |
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Troubleshooting Form |
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Accessory Connections |
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Refrigerant Circuit Diagram |
47 |
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Electrical - Thermostat Wiring |
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Revision History |
48 |
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ECM Blower Control |
24-25 |
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2
Installation, Operation & Maintenance |
HTV/HTD/HTH SERIES |
Heat Controller, Inc. |
Safety
Warnings, cautions and notices appear throughout this manual. Read these items carefully before attempting any installation, service, or troubleshooting of the equipment.
DANGER: Indicates an immediate hazardous situation, which if not avoided will result in death or serious injury. DANGER labels on unit access panels must be observed.
WARNING: Indicates a potentially hazardous situation, which if not avoided could result in death or serious injury.
WARNING!
WARNING! To avoid the release of refrigerant into the atmosphere, the refrigerant circuit of this unit must be serviced only by technicians who meet local, state, and federal proficiency requirements.
CAUTION: Indicates a potentially hazardous situation or an unsafe practice, which if not avoided could result in minor or moderate injury or product or property damage.
NOTICE: Notification of installation, operation or maintenance information, which is important, but which is not hazard-related.
WARNING!
WARNING! All refrigerant discharged from this unit must be recovered WITHOUT EXCEPTION. Technicians must follow industry accepted guidelines and all local, state, and federal statutes for the recovery and disposal of refrigerants. If a compressor is removed from this unit, refrigerant circuit oil will remain in the compressor. To avoid leakage of compressor oil, refrigerant lines of the compressor must be sealed after it is removed.
CAUTION!
CAUTION! To avoid equipment damage, DO NOT use these units as a source of heating or cooling during the construction process. The mechanical components and filters will quickly become clogged with construction dirt and debris, which may cause system damage.
3
Installation, Operation & Maintenance |
HTV/HTD/HTH SERIES |
Heat Controller, Inc. |
General Information
Inspection
Upon receipt of the equipment, carefully check the shipment against the bill of lading. Make sure all units have been received. Inspect the packaging of each unit, and inspect each unit for damage. Insure that the carrier makes proper notation of any shortages or damage on all copies of the freight bill and completes a common carrier inspection report. Concealed damage not discovered during unloading must be reported to the carrier within 15 days of receipt of shipment. If not filed within 15 days, the freight company can deny the claim without recourse. Note: It is the responsibility of the purchaser to file all necessary claims with the carrier. Notify your equipment supplier of all damage within fifteen (15) days of shipment.
Storage
Equipment should be stored in its original packaging in a clean, dry area. Store units in an upright position at all times. Stack units a maximum of 3 units high.
Unit Protection
Cover units on the job site with either the original packaging or an equivalent protective covering. Cap the open ends of pipes stored on the job site. In areas where painting, plastering, and/ or spraying has not been completed, all due precautions must be taken to avoid physical damage to the units and contamination by foreign material. Physical damage and contamination may prevent proper start-up and may result in costly equipment cleanup.
Examine all pipes, fittings, and valves before installing any of the system components. Remove any dirt or debris found in or on these components.
Pre-Installation
Installation, Operation, and Maintenance instructions are provided with each unit. Horizontal equipment is designed for installation above false ceiling or in a ceiling plenum. Other unit configurations are typically installed in a mechanical room. The installation site chosen should include adequate service clearance around the unit. Before unit start-up, read all manuals and become familiar with the unit and its operation. Thoroughly check the system before operation.
Prepare units for installation as follows:
1.Compare the electrical data on the unit nameplate with ordering and shipping information to verify that the correct unit has been shipped.
2.Keep the cabinet covered with the original packaging until installation is complete and all plastering, painting, etc. is finished.
3.Verify refrigerant tubing is free of kinks or dents and that it does not touch other unit components.
4.Inspect all electrical connections. Connections must be clean and tight at the terminals.
5.Remove any blower support packaging (water-to-air units only).
6.Loosen compressor bolts on units equipped with compressor grommet vibration isolation until the compressor rides freely on the grommets.
7.Locate and verify any hot water generator (HWG), hanger, or other accessory kit located in the compressor section or blower section.
CAUTION!
CAUTION! DO NOT store or install units in corrosive environments or in locations subject to temperature or humidity extremes (e.g., attics, garages, rooftops, etc.). Corrosive conditions and high temperature or humidity can significantly reduce performance, reliability, and service life. Always move and store units in an upright position. Tilting units on their sides may cause equipment damage.
CAUTION!
CAUTION! CUT HAZARD - Failure to follow this caution may result in personal injury. Sheet metal parts may have sharp edges or burrs. Use care and wear appropriate protective clothing, safety glasses and gloves when handling parts and servicing heat pumps.
4
Installation, Operation & Maintenance |
HTV/HTD/HTH SERIES |
Heat Controller, Inc. |
General Information
Horizontal Unit Location
Units are not designed for outdoor installation. Locate the unit in an INDOOR area that allows enough space for service personnel to perform typical maintenance or repairs without removing unit from the ceiling. Horizontal units are typically installed above a false ceiling or in a ceiling plenum. Never install units in areas subject to freezing or where humidity levels could cause cabinet condensation (such as unconditioned spaces subject to 100% outside air). Consideration should be given to access for easy removal of the filter and access panels. Provide sufficient room to make water, electrical, and duct connection(s).
If the unit is located in a confined space, such as a closet, provisions must be made for return air to freely enter the space by means of a louvered door, etc. Any access panel screws that would be difficult to remove after the unit is installed should
be removed prior to setting the unit. Refer to Figure 3 for an illustration of a typical installation. Refer to unit specifications catalog for dimensional data.
Conform to the following guidelines when selecting unit location:
1.Provide a hinged access door in concealed-spline or plaster ceilings. Provide removable ceiling tiles in T-bar or lay-in ceilings. Refer to horizontal unit dimensions for specific series and model in unit specifications catalog. Size the access opening to accommodate the service technician during the removal or replacement of the compressor and the removal or installation of the unit itself.
2.Provide access to hanger brackets, water valves and fittings. Provide screwdriver clearance to access panels, discharge collars and all electrical connections.
3.DO NOT obstruct the space beneath the unit with piping, electrical cables and other items that prohibit future removal of components or the unit itself.
4.Use a manual portable jack/lift to lift and support the weight of the unit during installation and servicing.
The installation of water source heat pump units and all associated components, parts and accessories which make up the installation shall be in accordance with the regulations of ALL authorities having jurisdiction and MUST conform to all applicable codes. It is the responsibility of the installing
contractor to determine and comply with ALL applicable codes and regulations.
Mounting Horizontal Units
Horizontal units have hanger kits pre-installed from the factory as shown in Figure 1. Figure 3 shows a typical horizontal unit installation.
Horizontal heat pumps are typically suspended above a ceiling or within a soffit using field supplied, threaded rods sized to support the weight of the unit.
Use four (4) field supplied threaded rods and factory provided vibration isolators to suspend the unit. Hang the unit clear of the floor slab above and support the unit by the mounting bracket assemblies only. DO NOT attach the unit flush with the floor slab above.
Pitch the unit toward the drain as shown in Figure 2 to improve the condensate drainage. On small units (less than 8.8kW) ensure that unit pitch does not cause condensate leaks inside the cabinet.
Figure 1: Hanger Bracket
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Figure 2: Horizontal Unit Pitch
1/4” (6.4mm) pitch per foot for drainage
Drain
Connection
5
Installation, Operation & Maintenance |
HTV/HTD/HTH SERIES |
Heat Controller, Inc. |
Horizontal Installation
Figure 3: Typical Horizontal Unit Installation
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Air Coil - To obtain maximum performance, the air coil should be cleaned before start-up. A 10% solution of dishwasher detergent and water is recommended for both sides of the coil. A thorough water rinse should follow.
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6
Installation, Operation & Maintenance |
HTV/HTD/HTH SERIES |
Heat Controller, Inc. |
Field Conversion of Air Discharge
Overview - Horizontal units can be field converted between side (straight) and back (end) discharge using the instructions below.
Note: It is not possible to field convert return air between left or right return models due to the necessity of refrigeration copper piping changes.
Preparation - It is best to field convert the unit on the ground before hanging. If the unit is already hung it should be taken down for the field conversion.
Side to Back Discharge Conversion
1.Place unit in well lit area. Remove the screws as shown in Figure 4 to free top panel and discharge panel.
2.Lift out the access panel and set aside. Lift and rotate the discharge panel to the other position as shown, being careful with the blower wiring.
3.Check blower wire routing and connections for tension or contact with sheet metal edges. Reroute if necessary.
4.Check refrigerant tubing for contact with other components.
5.Reinstall top panel and screws noting that the location for some screws will have changed.
6.Manually spin the fan wheel to ensure that the wheel is not rubbing or obstructed.
7.Replace access panels.
Back to Side Discharge Conversion - If the discharge is changed from back to side, use above instruction noting that illustrations will be reversed.
Left vs. Right Return - It is not possible to field convert return air between left or right return models due to the necessity of refrigeration copper piping changes. However, the conversion process of side to back or back to side discharge for either right or left return configuration is the same. In some cases, it may be possible to rotate the entire unit 180 degrees if the return air connection needs to be on the opposite side. Note that rotating the unit will move the piping to the other end of the unit.
Figure 4: Left Return Side to Back
Water |
Remove Screws |
Connection End |
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Return Air
Side Discharge
Water
Connection End
Rotate
Return Air
Move to Side
Replace Screws
Water
Connection End
Back Discharge
Return Air
Drain
Discharge Air
Figure 5: Right Return Side to Back
Water
Connection End
Return Air
Supply Duct
Side Discharge
Water
Connection End
Return Air
Drain
Back Discharge
Discharge Air
7
Installation, Operation & Maintenance |
HTV/HTD/HTH SERIES |
Heat Controller, Inc. |
Horizontal Installation
Condensate Piping – Horizontal Units
Pitch the unit toward the drain as shown in Figure 2 to improve the condensate drainage. On small units (less than 2.5 tons/8.8 kW), insure that unit pitch does not cause condensate leaks inside the cabinet.
Install condensate trap at each unit with the top of the trap positioned below the unit condensate drain connection as shown in Figure 6. Design the depth of the trap (water-seal) based upon the amount of ESP capability of the blower (where 2 inches
[51mm] of ESP capability requires 2 inches [51mm] of trap depth). As a general rule, 1-1/2 inch [38mm] trap depth is the minimum.
Each unit must be installed with its own individual trap and connection to the condensate line (main) or riser. Provide a means to flush or blow out the condensate line. DO NOT install units with a common trap and/or vent.
Always vent the condensate line when dirt or air can collect in the line or a long horizontal drain line is required. Also vent when large units are working against higher external static pressure than other units connected to the same condensate main since this may cause poor drainage for all units on the line. WHEN A VENT IS INSTALLED IN THE DRAIN LINE, IT MUST BE LOCATED AFTER THE TRAP IN THE DIRECTION OF THE CONDENSATE FLOW.
Condensate Piping
Figure 6: Horizontal Condensate Connection
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* Some units include a painted drain connection. Using a threaded pipe or similar device to clear any excess paint accumulated inside this fitting may ease final drain line installation.
CAUTION!
CAUTION! Ensure condensate line is pitched toward drain 1/8 inch per ft [11mm per m] of run.
DUCT SYSTEM INSTALLATION
Duct System Installation
The duct system should be sized to handle the design airflow quietly. Refer to Figure 3 for horizontal duct system details or figure 8 for vertical duct system details. A flexible connector is recommended for both discharge and return air duct connections on metal duct systems to eliminate the transfer of vibration to the duct system. To maximize sound attenuation of the unit blower, the supply and return plenums should include internal fiberglass duct liner or be constructed from ductboard for the first few feet. Application of the unit to uninsulated ductwork
in an unconditioned space is not recommended, as the unit’s performance will be adversely affected.
At least one 90° elbow should be included in the supply duct to reduce air noise. If air noise or excessive air flow is a problem, the blower speed can be changed. For airflow charts, consult specifications catalog for the series and model of the specific unit.
If the unit is connected to existing ductwork, a previous check should have been made to insure that the ductwork has the capacity to handle the airflow required for the unit. If ducting is too small, as in the replacement of a heating only system, larger ductwork should be installed. All existing ductwork should be checked for leaks and repaired as necessary.
8
Installation, Operation & Maintenance |
HTV/HTD/HTH SERIES |
Heat Controller, Inc. |
Vertical Installation
Vertical Unit Location
Units are not designed for outdoor installation. Locate the unit in an INDOOR area that allows enough space for service personnel to perform typical maintenance or repairs without removing unit from the mechanical room/closet. Vertical units are typically installed in a mechanical room or closet. Never install units in areas subject to freezing or where humidity levels could cause cabinet condensation (such as unconditioned spaces subject to 100% outside air). Consideration should be given to access for easy removal of the filter and access panels. Provide sufficient room to make water, electrical, and duct connection(s).
If the unit is located in a confined space, such as a closet, provisions must be made for return air to freely enter the space by means of a louvered door, etc. Any access panel screws that would be difficult to remove after the unit is installed should
be removed prior to setting the unit. Refer to Figures 7 and 8 for typical installation illustrations. Refer to unit specifications catalog for dimensional data.
1.Install the unit on a piece of rubber, neoprene or other mounting pad material for sound isolation. The pad should be at least 3/8” [10mm] to 1/2” [13mm] in thickness. Extend the pad beyond all four edges of the unit.
2.Provide adequate clearance for filter replacement and drain pan cleaning. Do not block filter access with piping, conduit or other materials. Refer to unit specifications for dimensional data.
3.Provide access for fan and fan motor maintenance and for servicing the compressor and coils without removing the unit.
4.Provide an unobstructed path to the unit within the closet or mechanical room. Space should be sufficient to allow removal of the unit, if necessary.
5.Provide access to water valves and fittings and screwdriver access to the unit side panels, discharge collar and all electrical connections.
Downflow units may be installed directly on the floor. The optional internal electric heat is rated for zero clearance to combustible materials.
The installation of water source heat pump units and all associated components, parts and accessories which make up the installation shall be in accordance with the regulations of ALL authorities having jurisdiction and MUST conform to all applicable codes. It is the responsibility of the installing
contractor to determine and comply with ALL applicable codes and regulations.
Figure 7: Vertical Unit Mounting
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Figure 8: Typical Vertical Unit Installation Using Ducted
Return Air
Internally insulate supply duct for first 1.2 m each way to reduce noise
Use turning vanes in supply transition
Flexible canvas duct connector to reduce noise and vibration
Rounded return transition
Internally insulate return |
Rev.: 6/2/09S |
transition duct to reduce |
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noise |
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9
Installation, Operation & Maintenance |
HTV/HTD/HTH SERIES |
Heat Controller, Inc. |
Vertical Installation
Sound Attenuation for Vertical Units - Sound attenuation is achieved by enclosing the unit within a small mechanical room or a closet. Additional measures for sound control include the following:
1.Mount the unit so that the return air inlet is 90° to the return air grille. Refer to Figure 9. Install a sound baffle as illustrated to reduce line-of sight sound transmitted through return air grilles.
2.Mount the unit on an Unit Isolation Pad to minimize vibration transmission to the building structure. For more information on Unit Isolation Pads, contact your distributor.
Condensate Piping for Vertical Units - Vertical units utilize a condensate hose inside the cabinet as a trapping loop; therefore an external trap is not necessary. Figure 10a shows typical condensate connections. Figure 10b illustrates the internal trap for a typical vertical heat pump. Each unit must be installed with its own individual vent (where necessary) and a means to flush or blow out the condensate drain line. Do not install units with a common trap and/or vent.
Figure 10a: Vertical Condensate Drain
Figure 9: Vertical Sound Attenuation |
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3HU |
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Return |
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Air Inlet |
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* Some units include a painted drain connection. |
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Using a threaded pipe or similar device to clear |
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any excess paint accumulated inside this fitting |
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may ease final drain line installation. |
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Figure 10b: Vertical Internal Condensate Trap |
10
Installation, Operation & Maintenance |
HTV/HTD/HTH SERIES |
Heat Controller, Inc. |
Water Connection Installation
External Flow Controller Mounting
The Flow Controller can be mounted beside the unit as shown in Figure 12. Review the Flow Controller installation manual for more details.
Water Connections-Residential (Distributor) Models
Residential models utilize swivel piping fittings for water connections that are rated for 450 psi (3101 kPa) operating pressure. The connections have a rubber gasket seal similar to a garden hose gasket, which when mated to the flush end of most 1” threaded male pipe fittings provides a leak-free seal without the need for thread sealing tape or joint compound. Check for burrs and ensure that the rubber seal is in the swivel connector prior to attempting any connection (rubber seals are shipped attached to the swivel connector). DO NOT OVER TIGHTEN or leaks may occur.
The female locking ring is threaded onto the pipe threads which holds the male pipe end against the rubber gasket, and seals the joint. HAND TIGHTEN ONLY! DO NOT OVERTIGHTEN!
Figure 11: Water Connections
Swivel Nut
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Hand Tighten |
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Only! |
Stainless steel |
Do Not |
snap ring |
Overtighten! |
Gasket |
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Brass Adaptor |
GROUND-LOOP HEAT PUMP APPLICATIONS
Figure 12: Typical Ground-Loop Application
To Thermostat
High and
Low Voltage
Knockouts
Vibration Isolation Pad
CAUTION!
CAUTION! The following instructions represent industry accepted installation practices for closed loop earth coupled heat pump systems. Instructions are provided to assist the contractor in installing trouble free ground loops. These instructions are recommendations only. State/provincial and local codes MUST be followed and installation MUST conform to ALL applicable codes. It is the responsibility of the installing contractor to determine and comply with ALL applicable codes and regulations.
Pre-Installation
Prior to installation, locate and mark all existing underground utilities, piping, etc. Install loops for new construction before sidewalks, patios, driveways, and other construction has begun. During construction, accurately mark all ground loop piping on the plot plan as an aid in avoiding potential future damage to the installation.
Piping Installation
The typical closed loop ground source system is shown in Figure 12. All earth loop piping materials should be limited to polyethylene fusion only for in-ground sections of the loop. Galvanized or steel fittings should not be used at any time due to their tendency to corrode. All plastic to metal threaded fittings should be avoided due to their potential to leak in earth coupled applications. A flanged fitting should be substituted. P/T plugs should be used so that
flow can be measured using the pressure drop of the unit heat exchanger.
Earth loop temperatures can range between 25 and 110°F [-4 to 43°C]. Flow rates between 2.25 and 3 gpm per ton [2.41 to 3.23 l/m per kW] of cooling capacity is recommended in these applications.
Test individual horizontal loop circuits before backfilling. Test vertical U-bends and pond loop assemblies prior to installation. Pressures of at least 100 psi [689 kPa] should be used when testing. Do not exceed the pipe pressure rating. Test entire system when all loops are assembled.
Flushing the Earth Loop
Once piping is completed between the unit, Flow Controller and the ground loop (Figure 12), the loop is ready for final purging and charging. A flush cart with at least a 1.5 hp [1.1 kW] pump is
required to achieve enough fluid velocity in the loop piping system to purge air and dirt particles. An antifreeze solution is used in
11
Installation, Operation & Maintenance |
HTV/HTD/HTH SERIES |
Heat Controller, Inc. |
Ground-Loop Heat Pump Applications
most areas to prevent freezing. All air and debris must be removed from the earth loop piping before operation. Flush the loop with a high volume of water at a minimum velocity of 2 fps (0.6 m/s) in all piping. The steps below must be followed for proper flushing.
1.Fill loop with water from a garden hose through the flush cart before using the flush cart pump to insure an even fill.
2.Once full, the flushing process can begin. Do not allow the water level in the flush cart tank to drop below the pump inlet line to avoid air being pumped back out to the earth loop.
3.Try to maintain a fluid level in the tank above the return tee so that air cannot be continuously mixed back into the fluid. Surges of 50 psi (345 kPa) can be used to help purge air pockets by simply shutting off the return valve going into the
flush cart reservoir. This “dead heads” the pump to 50 psi (345 kPa). To purge, dead head the pump until maximum pumping pressure is reached. Open the return valve and a pressure surge will be sent through the loop to help purge air pockets from the piping system.
4.Notice the drop in fluid level in the flush cart tank when the return valve is shut off. If air is adequately purged from the system, the level will drop only 1-2 inches (2.5 - 5 cm) in a 10” (25 cm) diameter PVC flush tank (about a half gallon [2.3 liters]), since liquids are incompressible. If the level drops more than this, flushing should continue since air is still being compressed in the loop fluid. Perform the “dead head” procedure a number of times. Note: This fluid level drop is your only indication of air in the loop.
Antifreeze may be added before, during or after the flushing procedure. However, depending upon which time is chosen, antifreeze could be wasted when emptying the flush cart tank. See antifreeze section for more details.
Loop static pressure will fluctuate with the seasons. Pressures will be higher in the winter months than during the cooling season. This fluctuation is normal and should be considered when charging the system initially. Run the unit in either heating or cooling for a number of minutes to condition the loop to a homogenous temperature. This is a good time for tool cleanup, piping insulation, etc. Then, perform final flush and pressurize the loop to a static pressure of 50-75 psi [345-517 kPa] (winter) or 35-40 psi [241-276 kPa] (summer). After pressurization, be sure to loosen the plug at the end of the Grundfos loop pump motor(s) to allow trapped air to be discharged and to insure the motor housing has been flooded. This is not required for Taco circulators. Insure that the Flow Controller provides adequate flow through the unit by checking pressure drop across the heat exchanger and compare to the pressure drop tables at the back of the manual.
Antifreeze
In areas where minimum entering loop temperatures drop below 40°F [5°C] or where piping will be routed through areas subject to freezing, antifreeze is required. Alcohols and glycols are commonly used as antifreeze; however your local sales manager should be consulted for the antifreeze best suited to your area.
Low temperature protection should be maintained to 15°F [9°C] below the lowest expected entering loop temperature. For example, if 30°F [-1°C] is the minimum expected entering loop temperature, the leaving loop temperature would be 25 to 22°F [-4 to -6°C] and low temperature protection should be at 15°F [-10°C]. Calculation is as follows:
30°F - 15°F = 15°F [-1°C - 9°C = -10°C].
All alcohols should be premixed and pumped from a reservoir outside of the building when possible or introduced under the water level to prevent fumes. Calculate the total volume of fluid in the piping system. Then use the percentage by volume
shown in Table 2 for the amount of antifreeze needed. Antifreeze concentration should be checked from a well mixed sample using a hydrometer to measure specific gravity.
Low Water Temperature Cutout Setting - CXM Control When antifreeze is selected, the FP1 jumper (JW3) should be clipped to select the low temperature (antifreeze 10°F [-12.2°C])
set point and avoid nuisance faults (see “Low Water Temperature Cutout Selection” in this manual). Note: Low water temperature operation requires extended range equipment.
Table 1: Approximate Fluid Volume (gal.) per 100' of Pipe
Fluid Volume (gal [liters] per 100’ [30 meters) Pipe)
Pipe |
Size |
Volume (gal) [liters] |
||
|
|
|
||
|
1” |
4.1 [15.3] |
||
|
|
|
||
Copper |
1.25” |
6.4 [23.8] |
||
|
|
|
||
|
2.5” |
9.2 [34.3] |
||
|
|
|
||
Rubber Hose |
1” |
3.9 [14.6] |
||
|
|
|
||
|
3/4” IPS SDR11 |
2.8 [10.4] |
||
|
|
|
||
|
1” iPS SDR11 |
4.5 [16.7] |
||
|
|
|
||
|
1.25” IPS SDR11 |
8.0 [29.8] |
||
|
|
|
|
|
Polyethylene |
1.5” IPS SDR11 |
10.9 |
[40.7] |
|
|
|
|
||
2” IPS SDR11 |
18.0 |
[67.0] |
||
|
||||
|
|
|
||
|
1.25” IPS SCH40 |
8.3 [30.9] |
||
|
|
|
|
|
|
1.5” IPS SCH40 |
10.9 |
[40.7] |
|
|
|
|
|
|
|
2” IPS SCH40 |
17.0 |
[63.4] |
|
|
|
|
|
|
Unit Heat Exchanger |
Typical |
1.0 |
[3.8] |
|
|
|
|
|
|
Flush Cart Tank |
10” Dia x 3ft tall |
10 [37.9] |
||
[254mm x 91.4cm tall] |
||||
|
|
|
12
Installation, Operation & Maintenance |
HTV/HTD/HTH SERIES |
Heat Controller, Inc. |
Ground-Loop Heat Pump Applications
Table 2: Antifreeze Percentages by Volume
|
|
Minimum Temperature |
|
||
Type |
for Low Temperature Protection |
||||
|
|
|
|
|
|
10°F |
15°F |
20°F |
|
25°F |
|
|
|
||||
|
[-12.2°C] |
[-9.4°C] |
[-6.7°C] |
|
[-3.9°C] |
|
|
|
|
|
|
Methanol |
21% |
17% |
13% |
|
8% |
Propylene Glycol |
29% |
24% |
18% |
|
12% |
Ethanol* |
23% |
20% |
16% |
|
11% |
|
|
|
|
|
|
* Must not be denatured with any petroleum based product
GROUND-WATER HEAT PUMP APPLICATIONS
Open Loop - Ground Water Systems
Typical open loop piping is shown in Figure 13. Shut off valves should be included for ease of servicing. Boiler drains or other valves should be “tee’d” into the lines to allow acid flushing of the heat exchanger. Shut off valves should be positioned to allow flow through the coax via the boiler drains without allowing flow into the piping system. P/T plugs should be used so that pressure drop and temperature can be measured. Piping materials should be limited to copper or PVC SCH80. Note: Due to the pressure and temperature extremes, PVC SCH40 is not recommended.
Water quantity should be plentiful and of good quality. Consult table 3 for water quality guidelines. The unit can be ordered with either a copper or cupro-nickel water heat exchanger. Consult table 3 for recommendations. Copper is recommended for closed loop systems and open loop ground water systems that are not high in mineral content or corrosiveness. In conditions anticipating heavy scale formation or in brackish water, a cupro-
nickel heat exchanger is recommended. In ground water situations where scaling could be heavy or where biological growth such
as iron bacteria will be present, an open loop system is not recommended. Heat exchanger coils may over time lose heat exchange capabilities due to build up of mineral deposits. Heat exchangers must only be serviced by a qualified technician, as acid and special pumping equipment is required. Desuperheater coils can likewise become scaled and possibly plugged. In areas with extremely hard water, the owner should be informed that the heat exchanger may require occasional acid flushing. In some cases, the desuperheater option should not be recommended due to hard water conditions and additional maintenance required.
Water Quality Standards
Table 3 should be consulted for water quality requirements. Scaling potential should be assessed using the pH/Calcium hardness method. If the pH <7.5 and the Calcium hardness is less than 100 ppm, scaling potential is low. If this method yields numbers out of range of those listed, the Ryznar Stability and Langelier Saturation indecies should be calculated. Use the appropriate scaling surface temperature for the application, 150°F [66°C] for direct use (well water/open loop) and DHW (desuperheater); 90°F [32°F] for indirect use. A monitoring plan should be implemented in these probable scaling situations. Other water quality issues such as iron fouling, corrosion prevention and erosion and clogging should be referenced in Table 3.
Pressure Tank and Pump
Use a closed, bladder-type pressure tank to minimize mineral formation due to air exposure. The pressure tank should be sized to provide at least one minute continuous run time of the pump using its drawdown capacity rating to prevent pump short cycling. Discharge water from the unit is not contaminated in any manner and can be disposed of in various ways, depending on local building codes (e.g. recharge well, storm sewer, drain field, adjacent stream or pond, etc.). Most local codes forbid the use of sanitary sewer for disposal. Consult your local building and zoning department to assure compliance in your area.
The pump should be sized to handle the home’s domestic water load (typically 5-9 gpm [23-41 l/m]) plus the flow rate required for the heat pump. Pump sizing and expansion tank must be chosen as complimentary items. For example, an expansion tank that is too small can causing premature pump failure due to short cycling. Variable speed pumping applications should be considered for the inherent energy savings and smaller pressure tank requirements.
Water Control Valve
Note the placement of the water control valve in figure 13. Always maintain water pressure in the heat exchanger by placing the water control valve(s) on the discharge line to prevent mineral precipitation during the off-cycle. Pilot operated slow closing valves are recommended to reduce water hammer. If water hammer persists, a mini-expansion tank can be mounted on the piping to help absorb the excess hammer shock. Insure that the total ‘VA’ draw of the valve can be supplied by the unit transformer. For instance, a slow closing valve can draw up to 35VA. This
can overload smaller 40 or 50 VA transformers depending on the other controls in the circuit. A typical pilot operated solenoid valve draws approximately 15VA (see Figure 22). Note the special wiring diagrams for slow closing valves (Figures 23 & 24).
Flow Regulation
Flow regulation can be accomplished by two methods. One method of flow regulation involves simply adjusting the ball valve or water control valve on the discharge line. Measure the pressure drop through the unit heat exchanger, and determine flow rate from tables 9a through 9c. Since the pressure is constantly varying, two pressure gauges may be needed. Adjust the valve until the desired flow of 1.5 to 2 gpm per ton [2.0 to 2.6 l/m per kW] is achieved.
A second method of flow control requires a flow control device
13
Installation, Operation & Maintenance |
HTV/HTD/HTH SERIES |
Heat Controller, Inc. |
Ground-Water Heat Pump Applications
mounted on the outlet of the water control valve. The device is typically a brass fitting with an orifice of rubber or plastic material that is designed to allow a specified flow rate. On occasion, flow control devices may produce velocity noise that can be reduced by applying some back pressure from the ball valve located on the discharge line. Slightly closing the valve will spread the pressure
drop over both devices, lessening the velocity noise. NOTE: When
EWT is below 50°F [10°C], a minimum of 2 gpm per ton (2.6 l/m per kW) is required.
Water Coil Low Temperature Limit Setting
For all open loop systems the 30°F [-1.1°C] FP1 setting (factory setting-water) should be used to avoid freeze damage to the unit. See “Low Water Temperature Cutout Selection” in this manual for details on the low limit setting.
Figure 13: Typical Open Loop/Well Application
CAUTION!
CAUTION! Refrigerant pressure activated water regulating valves should never be used with this equipment.
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14
Installation, Operation & Maintenance |
HTV/HTD/HTH SERIES |
Heat Controller, Inc. |
Water Quality Standards
Table 3: Water Quality Standards
Water Quality |
HX |
Closed |
Open Loop and Recirculating Well |
|
Parameter |
Material |
Recirculating |
||
|
||||
|
|
|
|
Scaling Potential - Primary Measurement
Above the given limits, scaling is likely to occur. Scaling indexes should be calculated using the limits below
|
pH/Calcium Hardness |
All |
- |
pH < 7.5 and Ca Hardness <100ppm |
|
|
Method |
|
|
||
|
|
|
|
|
|
|
|
|
|
|
|
Index Limits for Probable Scaling Situations - (Operation outside these limits is not recommended)
Scaling indexes should be calculated at 66°C for direct use and HWG applications, and at 32°C for indirect HX use.
A monitoring plan should be implemented.
|
Ryznar |
|
All |
|
|
- |
6.0 - 7.5 |
|
|
Stability Index |
|
|
If >7.5 minimize steel pipe use. |
|
|||
|
|
|
|
|
|
|
||
|
Langelier |
|
All |
|
- |
-0.5 to +0.5 |
|
|
|
Saturation Index |
|
|
If <-0.5 minimize steel pipe use. Based upon 66°C HWG and |
|
|||
|
|
|
|
|
|
|
||
|
|
|
|
|
|
Direct well, 29°C Indirect Well HX |
|
|
|
|
|
|
|
|
|
|
|
|
Iron Fouling |
|
|
|
|
|
|
|
|
Iron Fe 2+ (Ferrous) |
|
|
|
- |
<0.2 ppm (Ferrous) |
|
|
|
(Bacterial Iron potential) |
|
All |
|
|
|||
|
|
|
|
|
|
If Fe2+ (ferrous)>0.2 ppm with pH 6 - 8, O2<5 ppm check for iron bacteria. |
|
|
|
Iron Fouling |
|
All |
|
- |
<0.5 ppm of Oxygen |
|
|
|
|
|
Above this level deposition will occur . |
|
||||
|
|
|
|
|
|
|
|
Corrosion Prevention
pH
Hydrogen Sulfide (H2S)
Ammonia ion as hydroxide, chloride, nitrate and sulfate compounds
Maximum
Chloride Levels
|
|
|
6 - 8.5 |
|
All |
|
Monitor/treat as |
|
|
|
needed |
|
|
|
|
|
|
- |
|
|
All |
|
|
|
|
|
|
|
All |
- |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Copper |
- |
|
|
Cupronickel |
- |
|
|
304 SS |
- |
|
|
316 SS |
- |
|
|
Titanium |
- |
6 - 8.5
Minimize steel pipe below 7 and no open tanks with pH <8
<0.5 ppm
At H2S>0.2 ppm, avoid use of copper and copper nickel piping or HX's. Rotten egg smell appears at 0.5 ppm level.
Copper alloy (bronze or brass) cast components are OK to <0.5 ppm.
<0.5 ppm
Maximum Allowable at maximum water temperature.
10 C |
24 C |
38 C |
<20ppm |
NR |
NR |
<150 ppm |
NR |
NR |
<400 ppm |
<250 ppm |
<150 ppm |
<1000 ppm |
<550 ppm |
< 375 ppm |
>1000 ppm |
>550 ppm |
>375 ppm |
Erosion and Clogging
|
|
<10 ppm of particles |
|
|
and a maximum |
Particulate Size and |
All |
velocity of 1.8 m/s |
Erosion |
|
Filtered for maximum |
|
841 micron [0.84 mm, |
|
|
|
|
|
|
20 mesh] size. |
|
|
|
<10 ppm (<1 ppm "sandfree” for reinjection) of particles and a maximum velocity of 1.8 m/s. Filtered for maximum 841 micron 0.84 mm,
20 mesh] size. Any particulate that is not removed can potentially clog components.
Rev.: 3/22/2012
The ClimateMastManufacturerr Water Quality Table provides water quality requirements for ClimateMasterManufacturer coaxial heat exchangers. When water properties are outside of those requirements, an external secondary heat exchanger must be used to isolate the heat pump heat exchanger from the unsuitable water. Failure to do so will void the warranty for the coaxial heat exchanger.
Notes:
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