Envision Peripherals Geothermal Indoor Split Heat Pumps Desuperheater Connections

Page 13

ENVISION SERIES INSTALLATION MANUAL

Desuperheater Connections

To maximize the benefits of the desuperheater a minimum 50-gallon water heater is recommended. For higher demand applications, use an 80-gallon water heater or two 50-gallon water heaters connected in a series as shown below. Electric water heaters are recommended. Make sure all local electrical and plumbing codes are followed when installing a desuperheater. Residential units with desuperheaters contain an internal circulator and fittings.

Note: Under certain conditions, Envision dual capacity units operate with very low refrigerant discharge temperatures, producing little or no water heating capability. This scenario occurs when the unit is operating with cold entering source water (loop or well). Allowing the desuperheater pump to operate during these conditions actually removes heat from the DHW circulating through the unit. To overcome this, Envision unit microprocessors have been programmed to disengage the desuperheater pump during such conditions. (During low capacity cooling operation, the pump will operate only if the DHW temperature entering the unit is less than the liquid line temperature plus 35º F. During high capacity cooling operation, the pump will operate only if the DHW temperature is less than the liquid line temperature plus 60º F.) Using a preheat tank, as shown in Figure 11, will maximize desuperheater capabilities.

Water Tank Preparation

To install a unit with desuperheater, follow these installation guidelines.

1.Turn off the power to the water heater.

2.Attach a water hose to the water tank drain connection and run the other end of the hose to an open drain or outdoors.

3.Close the cold water inlet valve to the water heater tank.

4.Drain the tank by opening the valve on the bottom of the tank, then open the pressure relief valve or hot water faucet.

5.Flush the tank by opening the cold water inlet valve to the water heater to free the tank of sediments. Close when draining water is clear.

6.Disconnect the garden hose and remove the drain valve from the water heater.

7.Refer to Plumbing Installation and Desuperheater Startup on page 14.

CAUTION: Elements will burn out if energized dry.

Figure 10: Typical Desuperheater Installation

3/4˝ x 3/4˝ x 1/2˝ tee

Cold

Hot

 

Water In

Water Out

Venting Waste Valve

or Vent Coupling

DHW

 

Water Out

P/T Relief

 

Valve

In

DHW

 

Water In

Drain Valve

Figure 11: Desuperheater Installation in Preheat Tank

3/4˝ x 3/4˝ x 1/2˝ tee

Cold

Hot

Water In

Water Out

Venting Waste Valve

or Vent Coupling

DHW

Water Out

 

P/T Relief

P/T Relief

 

Valve

Valve

 

In

 

DHW

 

 

Water In

Drain Valve

Drain Valve

13

Image 13
Contents 410A Refrigerant Ton Single Speed Ton Dual Capacity Envision Series Geothermal Indoor Split Heat PumpsModel Nomenclature Physical CharacteristicsTable of Contents General Installation Information Utilizing Existing Coil or Air Handler Equipment SelectionConnection to Air Coil Air Handler InstallationDual Fuel Systems Swivel Connections Residential Units Water PipingLine Set Sizes Air Handler Coil DataEnvision Matching Air Coil Surface Rows Tube Solenoid Valve Open Loop Well Water SystemsWater Quality Solenoid WiringMultiple Units on One Flow Center Closed Loop Ground Source SystemsWater Tank Preparation Desuperheater ConnectionsDesuperheater Startup Plumbing InstallationElectrical Thermostat WiringGeneral Electrical Data24V Accessory relay see SW2 3 for description of operation Wiring SchematicsHp Total Microprocessor Control Fan G only Cooling OperationLockout Conditions STG1 STG2 STG3 Emerg Single Speed Units Operation Logic DataFreeze Sensing Setting DIP Switch SettingsRefrigeration Position Description System ServiceSystem Evacuation Leak TestingInitial System Charge Calculation Charging the SystemDetermining Subcooling Pressure/Temperature Coversion Chart for R-410A Single Speed Models Unit Operating ParametersDual Capacity Models Unit Startup Before Powering Unit, Check The FollowingStartup Steps Final Evaluation Heating Cycle Analysis Unit Startup/TroubleshootingSingle Speed Pressure Drop and Recommended Flow RatesDual Capacity LED Definitions and Diagnostics TroubleshootingStandard Microprocessor Controls Refrigerant SystemsReplacement Procedures Preventive MaintenanceEnvision NZ Split Dimensional Data Physical DimensionsInstallation Notes