Hi Fakeha,
E+ puts plug loads exactly where you tell it to. There is no magic. If there is no insulation (which is normal) between perimeter and core zones, heat can effortlessly flow from the perimeter to the core. It depends only on an existing temperature difference to exist, as Jim said. If there is no dT, no heat will flow. The thermal capacitance of a gypsum wall is negligable, and the thermal resistance very low.
Could you briefly describe the outdoor, indoor and ground temperatures as well as how and where you defined the plugloads. What are the U-values of your walls, windows, floors and roofs? What is your window-to-wall ratio?
Jim mentioned the setpoints...What are they for the zones? I'm trying to get an idea of how your heat is flowing...
Have a look at the Sensible Heat Gain summary table in the AllSummary html.
Also, just a heads up to the rest of the community: v8.2 has included the slab and basement pre-processor as an object which can call the routines on timestep or hourly bases. This is a true ground coupling with 3D heat transfer modelling and will help many people
Jean Marais
b.i.g. bechtold
On 28.03.2015, at 22:04, "Jim Dirkes jim@xxxxxxxxxxxxxxxxxxxxxxxxxxx [EnergyPlus_Support]" <EnergyPlus_Support@xxxxxxxxxxxxxxx> wrote:
â??From your description, I cannot understand the problem. Here are some thoughts:
- All properly sized zones will be at the temperature setpoint. If the setpoint are identical, the zones will all be at the same temperature. (including the bottom floor core zone and middle floor core zone.)
- A core zone's temperature and cooling load are unaffected by the surrounding perimeter zones if all of the zones are at the same temperature.
- Also, a core zone on the lowest floor should have identical cooling energy to a middle floor if the internal loads are identical.
You may want to share the IDF so that it can be reviewed in more detail. In addition, you should note the specific variables that appear to be incorrect.On Sat, Mar 28, 2015 at 11:09 AM, Fakeha Sehar fakeha_s@xxxxxxxxx [EnergyPlus_Support] <EnergyPlus_Support@xxxxxxxxxxxxxxx> wrote:My query has not been answered. for a rectangular shaped building with five zones on each floor, one core zone and four perimeter zones, the core zone on the bottom floor should be more cooler than the similar mid and top floor's core zones. Does EnergyPlus consider high internal plug load density (sum of adjacent perimeter zones plug densities) for the core zone on the bottom floor? My simulation results show that it does.The sensible cooling rate is higher for the core zone on bottom floor than the mid and top floors core zones due to its high internal load heat gain.On Wednesday, March 11, 2015 11:33 AM, "Fakeha Sehar fakeha_s@xxxxxxxxx [EnergyPlus_Support]" <EnergyPlus_Support@xxxxxxxxxxxxxxx> wrote:
I am using E+ version 8.1. From the html report I observe that the plug load density for the core bottom zone is being considered as the sum of its surrounding perimeter zones plug load densities. This is further confirmed by observing the internal convective heat gain rate, heat added to air by internal loads, which is too high for the bottom core zone than similar mid/top floor's core zones.I have also checked the surface convection rate for the core zones, for the bottom floor this is low as compared to mid/top floors core zones. So the surfaces for the bottom floor core zone are not the reason for its high heat gain .Please let me know how this error can be removed.--James V Dirkes II, PE, BEMP, LEED AP
CEO/President
The Building Performance Team Inc.
1631 Acacia Dr, GR, Mi 49504
Direct: 616.450.8653
jim@xxxxxxxxxxxxxxxxxxxxxxxxxxx
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