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Re: [EnergyPlus_Support] Calculate Heating Load



UAdeltaT only applies for steady-state heat transfer.  Run with a 
DESIGNDAY with constant temperature (Daily Temperature Range = 0), no 
solar (Sky Clearness=0), and no internal gains.  You should be able 
to match the UAdeltaT calculation.  Be sure to use the interior and 
exterior convection coefficients reported in the output.

Mike Witte


On 9 Oct 2002, at 8:17, gagamere wrote:

> Hi, I have a qustion about heating load calculation.
> 
> I usually know that heating load is calculated as formula
> 
> Q=U*A*(T_i - T_o)
> 
> where, U=1/(R_o + R_i + R_c)
> 
> R_o : outer convection heat resistance
> R_i : inner convection heat resistance
> R_c : conduction heat resistance in wall
> 
> I review a result of heating rate using Energy Plus and another S/W.
> But I know to differ results.
> 
> So, I check the result of Energy Plus.
> 
> First, I get a convective coeff in result.
> 
> R_i = 1/ Surface Int Convection Coeff
> R_o = 1/ Surface Ext Convection Coeff
> R_c = thickness/Conductivity
> 
> Second, I calculate a overall heat conductivit[U] and get heating
> rating, Q.
> 
> Then, I know a value calculated by hand is bigger than a value 
> calculated by Energy Plus.
> 
> Please, tell me a reason.
> 
> 
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