[EnergyPlus_Support] Re: About exterior surface convection coefficient algorithms in EP

["hvacgeshen516" <geshen516@xxxxxxxxx>]

Hi friends.
Thanks for reply from all of you..

I think you are correct. and i check the mannual of TAS and IES.

Just some information:

IN TAS, 
hc=5.8+4.1Vm
In IES, 
hc=5.6+4V V<4.88; hc=7.2V^0.78 V>4.88
They all defined as hc which are stated as the convection coefficient;
HOWEVER, when calculating the exterior surface long wave radiation, they do not include long wave radiation with air..
so the hc in TAS and IES should be a combination of convection and radiation.

One more thing, In ENERGYPLUS,
if SIMPLE is used, will the long wave radiation between exterior surface and air be calculated again? or just omit.

Thanks 
xiangjing



--- In EnergyPlus_Support@xxxxxxxxxxxxxxx, Ben Polly <pollyben@...> wrote:
>
> The simple model calculates combined convective and radiative heat transfer coefficients.?Are you subracting off the contstant radiative portion when you compare to other algorithms??I'd also look into how the wind speed conversion (from weather station to surface centroid) affects your convection coefficients.?
> 
> Ben
> 
> 
> 
> ________________________________
> From: hvacgeshen516 <geshen516@...>
> To: EnergyPlus_Support@xxxxxxxxxxxxxxx
> Sent: Tuesday, June 2, 2009 12:56:38 AM
> Subject: [EnergyPlus_Support] About exterior surface convection coefficient algorithms in EP
> 
> 
> 
> 
> 
> If the algorithms except simple are chosen, the wind-driven convection coefficient will be much smaller than algorithms implemented by other software like TAS or IES. 
> 
> Is there any comments on this? 
> 
> Thanks and Regards
> Xiangjing =)
>




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