DHZECNJ3672 – HORIZONTAL ECONOMIZER (3-6 TON, HONEYWELL JADE)

Daikin horizontal economizer accessory for 3 to 5 ton packaged units (3 to 6 ton on the DCC and DCG series). Daikin publishes it as fully modulating with up to 100% fresh air, a Honeywell economizer control, a single adjustable enthalpy control convertible to dual enthalpy, and adjustable minimum fresh air. It ships factory wired.

Specifications published by the manufacturer. Source: manufacturer documentation.

Specs

• BrandMcDaniel Metals
• Part NumberDHZECNJ3672
• TypeHorizontal economizer
• Capacity Range3 - 6 ton package units
• ControllerHoneywell JADE
• EnthalpySingle adjustable, convertible to dual
• Outside AirUp to 100% fresh air
• Minimum PositionAdjustable
• ModulationFully modulating
• WiringFactory wired
• Weight75 lb

Fits these models

• DCG036 - DCG072
• DCH036 - DCH072
• DSC036 - DSC072
• DSG036 - DSG072
• DSH036 - DSH072

What does an economizer actually do?

It brings in outdoor air for free cooling when outdoor conditions are better than return air, and closes down to minimum ventilation when they are not. On a packaged rooftop it is a damper section, an actuator and a controller with sensors. When it works, the compressor stays off and the fan does the cooling.

Does an economizer make sense in Dallas?

Less than in a dry climate, and the reason is humidity. A dry-bulb-only controller looking at 72F outdoor air will happily open on a muggy morning and bring in air that is cooler but far wetter, and then the coil pays for it. Enthalpy or differential enthalpy control is what makes economizing honest in DFW, because it compares total heat rather than temperature. The free-cooling hours here are real but they cluster in shoulder seasons and at night.

Why do so many economizers not work?

Because nothing tells you when they fail. Stuck actuators, dampers seized with grit, disconnected linkage, failed or drifted sensors and controllers left on a default setpoint are all common, and the unit keeps cooling on the compressor so nobody notices. That is exactly why fault detection and diagnostics is now required on many new economizers - the failure mode is silent and expensive.

What do I have to match?

The unit. Economizer sections are built for a specific rooftop cabinet and airflow, and the controller has to speak to that unit's controls. Bring the full model and serial number off the rating plate.