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Swapping Unitary Water cooling coil with the DX coil

asked 2021-05-18 02:37:18 -0500

Debayan93's avatar

updated 2021-05-25 12:11:09 -0500


I am looking to connect an unitary DX Cooling coil with 2 stage Humidity control to existing CHW loop in a VAV HVAC template where I initially replaced the Unitary Water cooling coil with the DX coil. However, after deleting the unitary water coil and adding the unitary DX coil, the ''Connect Components" does not work. In case without connecting the CHW loops to AHU, it runs into simulation error.

I am currently using DB v6.1.6. I don't know if it's a exiting issue to resolve or any other I way I can solve the swapping of the coils which is mentioned in DB help file:

I am looking if anyone has done it previously which handles the upper relative humidity control in improved way. Following in the attached is what I am looking to achieve (The red marked coil I am looking to swap as mentioned).

HVAC Template



Edit1: I have added the new HVAC after deleting the CHW and Condenser loops. Modified HVAC Template after Deleting Loops

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answered 2021-05-21 05:22:49 -0500

jan stasek's avatar

The DX coil does not require a connection to CHW Loop. If you replace the Water cooling coil with a DX coil, you have to delete the CHW Loop and Condenser Loop as well. You can´t have a loop without a connection.

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Hi jan,

I deleted both the loops after which the leads me to the following error:

Error in HVAC definition: Humidity setpoint manager for unitary coil must be defined on the same node as temperature setpoint manager.

I have added the updated HVAC in the original question.

Debayan93's avatar Debayan93  ( 2021-05-25 12:08:28 -0500 )edit

You have to add an extra setpoint manager next to your schema's existing temperature setpoint manager and set the dehumidification control mode.

jan stasek's avatar jan stasek  ( 2021-05-25 13:44:34 -0500 )edit

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Asked: 2021-05-18 02:37:18 -0500

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Last updated: May 25 '21