Re: [EnergyPlus_Support] The setting of material

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

Your results sound reasonable for comparing a building without thermal mass to 
a building with thermal mass.  One would expect the cooling load to have a 
lower peak and be spread over more hours of the day when there is mass present.

> Is that generally saying the electicity consumption of AC is more 
> sensitive on the internal heat gain
> rather than the factor of solar gain in actual situation, or say in this 
> case?

I do not think that a general rule can be concluded from this.  The importance 
of internal gains vs. solar gain depends on many other factors besides the 
amount of thermal mass.

Mike


On 25 Jul 2006 at 18:33, HSIEH Chun-Ming wrote:

> Hello
> 
> I am writing the mail to ask about the settings of building material. 
> (Metrial: Regular-R and Material: Regular)
> I simply compares the simulation results (electricity consumption of AC)
> and found that the results showed huge differnece between these two cases.
> 
> It was a simulation for a residentail builing (air conditioners were on 
> for 24 hours for all space).
> The window wall ratio was about 16%.
> The number of people during the daytime was  less than half of that 
> during the nighttime.
> 
> 1) Material: Regular-R : 
>      The results showed that the electricity consumption of AC highly 
> depended on the solar gain.
>      The electric power during the daytime is higher, which was about 
> 1.5 times of that during nighttime.
> 
> However,
> 2) Material:Regular :
>      The heat gain from internal gain from people, lights and equipment 
> played a very important role in determining the building energy use.
>      The electric power during the nighttime is higher than the case of 
> daytime.
> 
> After version 1.2.1.012, EnergyPlus suggests that when we use 
> Material:Regular-R:
> The builfing has no thermal mass which can cause an unstable solution.
> Use MATERIAL:REGULAR for all opaque material types except vey light 
> insulation layers
> 
> Is that generally saying the electicity consumption of AC is more 
> sensitive on the internal heat gain
> rather than the factor of solar gain in actual situation, or say in this 
> case?
> Thank you very much.
> 
> Chunming
> 
> 
> 
> [Non-text portions of this message have been removed]
> 
> 
> 
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> 


========================================================
Michael J. Witte, GARD Analytics, Inc.
EnergyPlus Testing and Support      
EnergyPlus-Support@xxxxxxxx





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