[TRNSYS-users] Air-air heat pump: performance data files

[David BRADLEY]

Jacopo,

  It may be that the evaporator temperatures in the default heating 
performance file do not correspond with the range of evaporator 
temperatures that are occurring during your simulation. Type954 is able 
to interpolate within the range of temperatures (and flow rates, etc.) 
that is given in the file. However, it cannot extrapolate beyond the 
range of numbers given. If you have COP values for ambient temperatures 
from 5C to 20C in the data file but the ambient temperature in your 
weather data is consistently below 5C then the COP corresponding to 5C 
would always be returned. Have a look in your *.log file; if the data 
file is often being accessed with temperatures above or below the range 
there will be a warning written there.

kind regards,

  David


On 2/4/2023 11:54 AM, Jacopo Valente via TRNSYS-users wrote:
>
> Dear all,
>
> i’m using the type 954 to model an air-to-air heat pump. Analyzing the 
> results of my simulation, the COP is almost constant during the 
> heating working. I’m using the default performance data file. The 
> problem is only for the heating working, while the COP varies for the 
> cooling working.
>
> I can suppose there is some problem with the default heating 
> performance data.
>
> Can u help me please?
>
> I try to attach an image of COP curve:
>
> Thanks.
>
> Best regards,
>
> Jacopo Valente
>
>
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-- 
***************************
David BRADLEY
Principal
Thermal Energy System Specialists, LLC
3 North Pinckney Street - suite 202
Madison, WI  53703 USA

P:+1.608.274.2577
d.bradley at tess-inc.com

http://www.tess-inc.com
http://www.trnsys.com
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