RE: [EnergyPlus_Support] Warning for Coil:Cooling:DX:SingleSpeed

As indicated by the error message, you are running DX cooling in Winter. Jan 14 in Chicago.

Dr. Li

To: EnergyPlus_Support@xxxxxxxxxxxxxxx
From: eee.javed@xxxxxxxxx
Date: Wed, 28 Dec 2011 12:32:54 +0000
Subject: [EnergyPlus_Support] Warning for Coil:Cooling:DX:SingleSpeed

Hi All,

I am trying to run DX cooling coil and getting following repetitive error , what could be the possible solution for the same.

** Warning ** Coil:Cooling:DX:SingleSpeed "SPACE5-1 PTAC COOLING COIL" - Full load outlet air dry-bulb temperature < 2C. This indicates the possibility of coil frost/freeze. Outlet temperature = -4.83 C.
** ~~~ ** ...Occurrence info = Chicago Ohare Intl Ap IL USA TMY3 WMO#=725300, 01/14 08:38 - 08:45
** ~~~ ** ... Possible reasons for low outlet air dry-bulb temperatures are: This DX coil
** ~~~ ** 1) may have a low inlet air dry-bulb temperature. Inlet air temperature = 10.835 C.
** ~~~ ** 2) may have a low air flow rate per watt of cooling capacity. Check inputs.
** ~~~ ** 3) is used as part of a HX assisted cooling coil which uses a high sensible effectiveness. Check inputs.
** Warning ** Coil:Cooling:DX:SingleSpeed "SPACE3-1 PTAC COOLING COIL" - Air-cooled condenser inlet dry-bulb temperature below 0 C. Outdoor dry-bulb temperature = -4.40
** ~~~ ** ... Occurrence info = Chicago Ohare Intl Ap IL USA TMY3 WMO#=725300, 01/14 10:00 - 10:15
** ~~~ ** ... Operation at low ambient temperatures may require special performance curves.
** Warning ** Coil:Cooling:DX:SingleSpeed "SPACE3-1 PTAC COOLING COIL" - Full load outlet air dry-bulb temperature < 2C. This indicates the possibility of coil frost/freeze. Outlet temperature = 8.52E-002 C.
** ~~~ ** ...Occurrence info = Chicago Ohare Intl Ap IL USA TMY3 WMO#=725300, 01/14 10:00 - 10:15
** ~~~ ** ... Possible reasons for low outlet air dry-bulb temperatures are: This DX coil
** ~~~ ** 1) may have a low inlet air dry-bulb temperature. Inlet air temperature = 15.011 C.
** ~~~ ** 2) may have a low air flow rate per watt of cooling capacity. Check inputs.
** ~~~ ** 3) is used as part of a HX assisted cooling coil which uses a high sensible effectiveness. Check inputs.
** Warning ** Coil:Cooling:DX:SingleSpeed "SPACE1-1 PTAC COOLING COIL" - Air-cooled condenser inlet dry-bulb temperature below 0 C. Outdoor dry-bulb temperature = -4.40
** ~~~ ** ... Occurrence info = Chicago Ohare Intl Ap IL USA TMY3 WMO#=725300, 01/14 10:45 - 11:00
** ~~~ ** ... Operation at low ambient temperatures may require special performance curves.
** Warning ** Coil:Cooling:DX:SingleSpeed "SPACE1-1 PTAC COOLING COIL" - Full load outlet air dry-bulb temperature < 2C. This indicates the possibility of coil frost/freeze. Outlet temperature = 1.79 C.
** ~~~ ** ...Occurrence info = Chicago Ohare Intl Ap IL USA TMY3 WMO#=725300, 01/14 15:00 - 15:15
** ~~~ ** ... Possible reasons for low outlet air dry-bulb temperatures are: This DX coil
** ~~~ ** 1) may have a low inlet air dry-bulb temperature. Inlet air temperature = 15.972 C.
** ~~~ ** 2) may have a low air flow rate per watt of cooling capacity. Check inputs.
** ~~~ ** 3) is used as part of a HX assisted cooling coil which uses a high sensible effectiveness. Check inputs.
************* Simulation Error Summary *************
*************
************* ===== Recurring Error Summary =====
************* The following recurring error messages occurred.
*************
************* ** Warning ** Coil:Cooling:DX:SingleSpeed "SPACE5-1 PTAC COOLING COIL" - Low condenser dry-bulb temperature error continues...
************* ** ~~~ ** This error occurred 45 total times;
************* ** ~~~ ** during Warmup 0 times;
************* ** ~~~ ** during Sizing 0 times.
************* ** ~~~ ** Max=-2.8 [C] Min=-7.2 [C]
*************
************* ** Warning ** Coil:Cooling:DX:SingleSpeed "SPACE5-1 PTAC COOLING COIL" - Full load outlet temperature indicates a possibility of frost/freeze error continues. Outlet air temperature statistics follow:
************* ** ~~~ ** This error occurred 45 total times;
************* ** ~~~ ** during Warmup 0 times;
************* ** ~~~ ** during Sizing 0 times.
************* ** ~~~ ** Max=-2.888928 Min=-4.833602
*************
************* ** Warning ** Coil:Cooling:DX:SingleSpeed "SPACE3-1 PTAC COOLING COIL" - Low condenser dry-bulb temperature error continues...
************* ** ~~~ ** This error occurred 26 total times;
************* ** ~~~ ** during Warmup 0 times;
************* ** ~~~ ** during Sizing 0 times.
************* ** ~~~ ** Max=-2.8 [C] Min=-4.75 [C]

Any help is appreciated.

Thanks!

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