York HFC-410A manual Duct Considerations, Unit Orientation, Horizontal Applications, Economizer

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FORM 100.50-EG5 (108)

persons. Erecting a fence around the unit is common practice.

Roof curb – YORK offers optional roof curbs designed specifically for the Eco2 footprint. This curb comes as an open condenser model and is shipped disassembled and requires field assem- bly and installation. For bottom supply and return openings, the curbs have matching connections to ease installation. A pipe chase that matches the rooftop unit pipe chase is also included in the curb footprint for through-the-curb utility connections. The curb should be located according to the loca- tion recommendations above, and properly sealed to prevent moisture and air leakage into and out of the duct system. Flexible collars should be used when connecting the duct work to prevent unit noise transmission and vibration into the building.

Duct work should be supported independently of the unit.

TABLE 1 – SUPPLY-AIR DUCT-CONNECTION CONFIGURATIONS

Unit Configuration

 

Supply Air

 

 

Bottom

 

Left

Right

 

 

 

 

Cooling only



 





 

50-65 Tons

Cool/gas heat 375-750 MBH



 



N/A

 

Cool/gas heat 1,125 MBH



 

N/A

N/A

TABLE 2 – RETURN-AIR DUCT-CONNECTION CONFIGURATIONS

 

 

Unit Configuration

 

Return Air

 

 

 

Bottom

Left

Rear

 

 

 

 

No exhaust

 



 





 

 

 

 

 

 

 

 

 

50-65 Tons

Barometric relief damper

 



 



N/A

 

 

Powered exhaust fan

 



 



N/A

 

DUCT CONSIDERATIONS

Unlike competitive units where air can leave the rooftop unit stratified across the width of the unit, the Eco2 unit sufficiently mixes airflow to ensure consistent air tem- perature from the unit. No special Tee considerations are required and the unit may be oriented either way.

UNIT ORIENTATION

For applications with multiple rooftop units located in close proximity on the roof, the orientation of the unit may be important to reduce the potential for re-entrain- ment of outside airflow. Regardless of the outside air and exhaust air openings on a unit, all rooftop applications can permit recirculation of exhaust air to the return, if applied improperly.

HORIZONTAL APPLICATIONS

The spectrum of applications for roof top units in today’s market is continuing to grow wider by the day. Flexibil- ity in unit design and construction is a must in today’s market in order to insure safe and sound applications of HVAC equipment. The Eco2 has been designed for spe- cific application of horizontal supply and return airflow taking the guess work out of unit application by building a unit specific to these needs. If the application calls for horizontal supply and return air, YORK can ship it from the factory as a horizontal unit. This option elevates the need for field modification of equipment, saving time and money. The Eco2 can support a left discharge on all units except 1,125 MBH gas, and/or right discharge on all cooling-only units. Return air can be brought through the end or side return air inlet making the unit specific to building needs.

ECONOMIZER

The economizer section is used for ventilation of the conditioned space to maintain indoor air quality, and also to reduce energy consumption by using outdoor air cooling in lieu of mechanical cooling. If outdoor air is appropriate for cooling, but not sufficient for the cooling demand, mechanical cooling will stage on as necessary until the cooling load is met.

Dual (comparative or differential) enthalpy operation is the most accurate and efficient means of economizer operation. The unit controller monitors the return and outside air energy content, and selects the lower of the two for operation.

NOTE:

 

This diagram is provided as a visual reference of the Eco2 discharge & return air openings & locations for all sizes. Please refer to the dimensional

 

data for exact size & location of panels and openings.

LD08045

JOHNSON CONTROLS

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Contents 90.1 AshraeCompliant MEA 231-02-EIntroduction Indoor air quality features for the indoor environ- mentLower total cost of ownership Simplicity Elite controller OptionTable of Contents Features and Benefits Filter Options CommunicationsOutside AIR Damper Options Relief SystemCabinet Features and Options Condenser Features and OptionsEvaporator Section Roof CurbsAccessories Application Data Unit PlacementGeneral LocationUnit Orientation Duct ConsiderationsHorizontal Applications EconomizerHarsh Environments Condenser and Evaporator Coil Protection VAV Supply AIR Pressure ControlCopper-Fin Evaporator and Condenser Coil Building Pressure Control SystemsAcoustical Considerations This page intentionally left blank York NomenclaturePhysical Data Physical Data050 051 060 061 Gas Furnaces ModelMinimum OA Temp for Mech. Cig Low Ambient Option Min. OA Temp Minimum Airflow HeatingIplv Ieer ModelEER Model Supply Blower Cooling Only Gas Heat TypeAir Altitude feet Temp Altitude and Temperature CorrectionsALTITUDE/TEMPERATURE Conversion Factor Cooling Performance DATA* 50 TON Standard Capacity Cooling Performance Data 050 ModelCooling Performance DATA* 55 TON High Capacity Cooling Performance Data 051 ModelCooling Performance DATA* 60 TON Standard Capacity Cooling Performance Data 060 ModelCooling Performance DATA* 65 TON High Capacity Cooling Performance Data 061 ModelSupply Fan Data Total Static Pressure inches of water columnCFM STD. AIR BHP RPM CFM Component Static Pressure DropsExhaust FAN Motor Sizing Instructions Exhaust Fan DataCFM STD AIR BHP RPMElectrical Data Electrical Service SizingLoad Definitions RLA LRAUnit Size Quantity FLAFans AmpsControls Unoccupied / Occupied SwitchingGAS Heating Operation Morning WARM-UPEconomizer Operation Ventilation Control SequencesExhaust Control Sequences LOW-AMBIENT/HEAD-PRESSURE Control Operation Smoke Purge SequenceSupply FAN Operation Cooling OperationHeating Operation POWER-SUPPLY-CONDUCTOR Size RangeDual-Point TB Supply Single-PointGeneral Arrangement Drawing General ArrangementSide Supply / Rear Return DrawingTOP View DrawingsGeneral Arrangement Drawing Curb Layout DrawingUnit Weights Unit Corner Weights Guide Specifications Equipment WarrantiesProduct Specification Unit ConstructionEvaporator Section Filter SectionSupply Fan Section Discharge PlenumCondenser Section Controls Simplicity Elite Installation ExecutionInspection and START-UP Supervision ALL Rights Reserved