[TRNSYS-users] Type954

jeannieboef jeannieboef at gmail.com
Mon Nov 19 21:52:53 PST 2012


thanks Jeff. you're spot on. I just couldn't find the documentation on  
this object and it isn't always clear when the outside fan or inside  
fan are meant.

thanks again.

Sent from my iPhone

On 19.11.2012, at 22:28, Jeff Thornton <thornton at tess-inc.com> wrote:

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> <I have the following situation. I have an input data file with the  
> QCOOL from a server room which was served by a split unit. Now I am  
> trying to find the electrical consumption of the split unit, both  
> indoor and outdoor.
> I was hoping to modulate the indoor fan flow until the delivered  
> cooling to the room equals my QCOOL. I set parameter10 "Total air  
> flow rate" (the air flow over the indoor unit coil) to -1, so that I  
> can pass it the flow as described. I have an itterative controller  
> that watches the total cooling rate of the type, compares it to my  
> QCOOL data, and tries to set the input4 "Return air flow rate" (the  
> flow rate over the inside unit coil) so that the cooling powers  
> match. Various flow rates seem to have no effect. Any ideas?>
>
>
>
> That model uses the user-provided flow rate and then "looks up" the  
> performance of the heat pump in the external data file given the  
> temperatures, flow rate, etc.  Did you modify the external data file  
> to provide performance at the off-rated flow conditions such that  
> you can back out the capacity at the current flow rate?  If you're  
> using the default files, the flow rates are set pretty close to the  
> nominal flow rate - and the model does not extrapolate beyond the  
> data points - so you're not going to see a difference in capacity as  
> you slow the air flow down or speed it up past the current minimum  
> and maximum values in the data file.
>
>
>
> Jeff
>
> ---
> Jeff Thornton
>
> President - TESS LLC
>
> 22 N. Carroll Street, Madison WI USA 53703
>
> Office: (608) 274-2577  Fax: (608) 278-1475
>
> www.tess-inc.com
>
> E-Mail: thornton at tess-inc.com
>
>
>
> On 11/19/2012 2:31 am, Jean Marais wrote:
>
>> Dear Group,
>>
>> Regards,
>> Jean.
>>
>
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