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[EnergyPlus_Support] Re: Air to Air heatpump error

Thanks for your response.

Just to confirm, 1.4 degrees is the supply air temperature (outlet temperature) not the inlet air temperature (the inlet (or return) air temperature is 13.4 and its cooling the air to 1.4 degrees when it should be heating).

Any other suggestions on how to solve this error??

Cheers



--- In EnergyPlus_Support@xxxxxxxxxxxxxxx, dashamir marini <dashamirmarini@...> wrote:
>
> The same warning have occured also in my model simulation where I hadn't Air-to-Air heat pump but Air To-Water heat pump. The warning is happening in Cooling Coil (evaporator) side because inlet air temperature is 1.4 Celcius so frost/freeze will occure. The lowest limit air inlet temperature for Air to Water is 5 Cel, after this temperature frost will begin to acomulate on evaporator (I'm not sure the same value 5 Cel  for air to air HP, but think be so), this is the reason why air source heat pump are not convenient in cold climates.
> 
>  
> 
> 
> --- On Thu, 12/17/09, Karen <bills2828@...> wrote:
> 
> From: Karen <bills2828@...>
> Subject: [EnergyPlus_Support] Air to Air heatpump error
> To: EnergyPlus_Support@xxxxxxxxxxxxxxx
> Date: Thursday, December 17, 2009, 8:51 PM
> 
> 
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>       I keep getting the warnning
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> 
> ** Warning ** Coil:Cooling: DX:SingleSpeed "128376 COOLING COIL" - Full load outlet air dry-bulb temperature < 2C. This indicates the possibility of coil frost/freeze. Outlet temperature =   1.40 C.
> 
>    **   ~~~   **  ...Occurrence info = IBM  BARTON, 04/20 11:10 - 11:15
> 
>    **   ~~~   ** ... 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 = 13.537 C.
> 
>    **   ~~~   **    2) may have a low air flow rate per watt of cooling capacity. Check inputs.
> 
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> 
> It appears to me that it is trying to cool when it should be heating (the return air temp is below set point).
> 
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> 
> Does anyone have any suggestions?
>




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