The following 3 warnings seem to always come together. I've bolded the items that I am particularly confused about. My understanding of the warning is that there is a risk of frost on the condenser based on the temperature of the air coming off of the condenser. Scrolling down, you can find reference to an outdoor air temperature and an inlet air temperature (both bolded). I am confused as to why the inlet air to the condenser would not be roughly equal to the outdoor air temperature. Also, the inlet air temperature is significantly warmer than the outlet air temperature. This makes no sense to me - is the inlet air temperature here somehow referring to the evaporator coil (it is roughly what I would expect the return air temperature to be)? If so, what does this have to do with frost risk? Thanks.
* Warning * CalcDoe2DXCoil: Coil:Cooling:DX:SingleSpeed="1 SPD DX CLG COIL" - Air volume flow rate per watt of rated total cooling capacity is out of range at 2.479E-005 m3/s/W. * ~~~ * Environment=RUN PERIOD 1, at Simulation time=01/02 07:00 - 08:00 * ~~~ * Expected range for VolumeFlowPerRatedTotalCapacity=[2.684E-005--6.713E-005] * ~~~ * Possible causes include inconsistent air flow rates in system components, * ~~~ * or variable air volume [VAV] system using incorrect coil type.
* Warning * CalcDoe2DXCoil: Coil:Cooling:DX:SingleSpeed "1 SPD DX CLG COIL" - Air-cooled condenser inlet dry-bulb temperature below 0 C. Outdoor dry-bulb temperature = -5.60 * ~~~ * ... Occurrence info = RUN PERIOD 1, 01/02 07:00 - 07:03 * ~~~ * ... Operation at low ambient temperatures may require special performance curves.
* Warning * CalcDoe2DXCoil: Coil:Cooling:DX:SingleSpeed "1 SPD DX CLG COIL" - Full load outlet air dry-bulb temperature < 2C. This indicates the possibility of coil frost/freeze. Outlet temperature = -1.24 C. * ~~~ * ...Occurrence info = RUN PERIOD 1, 01/02 07:09 - 07:12 * ~~~ * ... 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 = 21.582 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.
