Re: [EnergyPlus_Support] Using 2D radiant slab calc vs 1D

["Michael J. Witte" <mjwitte@xxxxxxxx>]

>From the radiant slab expert . . .  Mike

-----

Yes, the 2D calculation should be more accurate than the 1D simulation.  The 1D 
simulation spreads the calculated heat flux out over a plane which is probably 
more appropriate for the resistance heating radiant systems. The 2D simulation 
concentrates the heat source/sink on a line.  This is more representative of 
what is happening within an actual system.  The 1D and 2D simulations will 
yield the same surface temperature if the same flux is provided to both.  
However, because generally the water temperature is similar between the two 
models based on the plant controls.  This will cause a difference in flux and 
thus a different surface temperature.  The 2D simulation is more accurate at 
the cost of taking longer to calculate the conduction transfer function 
coefficients that are needed to solve for heat transfer through the system.  

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On 13 Oct 2006 at 1:46, Ian Doebber wrote:

> I compared the outputs between using the 1D and 2D for the radiant floor
> simulation.  The 2D calculation determines a higher surface temperature and
> therefore lower cooling rate.  Is the 2D calculation more
> conservative/accurate?  What type of output differences should I expect
> between these calculations. 
> 
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