Unexplained electricity consumption in attic thermal zone

asked 2015-07-31 15:50:51 -0600

rkbest
1392 ●1 ●4 ●13

updated 2016-10-20 11:23:03 -0600

In My model of a commercial building I created 8 thermal zones where 7 are rooms and 1 representing the attic. However, as the attic does not have any HVAC supplying conditioned air, I left it without any terminal unit supplying any air.

In my simulation report I see Annual Energy GJ as Electricity:Zone:THERMAL ZONE 8 237.89 Electricity:Zone:THERMAL ZONE 1 46.85 Electricity:Zone:THERMAL ZONE 2 160.37 The TZ 8 does not have a terminal unit or any electrical equipment or any people schedule to it assigned. What is contributing to the total of 237.89 GJ as annual electricity. 2. My understanding is the HVAC electricity = Fans+Cooling+heating, However, is the VRF system electricity*COP=(Sum of thermal zone sensible cooling/heating) ? I have measured cooling delivered data and want to match with the model for verification. What variables will give the cooling delivered aggregate for daily/monthly/ yearly data. I am bit lost in the ENergyPlus output report nomenclatures.

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@rkbest you might get a better response if you give the question a more meaningful name, like "Unexplained electricity consumption in attic thermal zone"

aparker ( 2015-07-31 17:06:57 -0600 )edit

Is it possible you are looking at total electricity, vs. just HVAC electricity? It is likely you have a default space type assigned for your building (you can check this by selecting the building object in the facility tab). If this is the case just make a new space type for attic that is empty expect for any infiltration you want to include in the attic. Then assign this space type to the attic space/zone. It will replace the default space type.

David Goldwasser ( 2015-08-03 12:06:48 -0600 )edit

I did add a new space type as you suggested, however, I don't see how can edit the infiltration. Also, I see other space type with loads, multiplier, definition, schedule etc. All I have is an empty attic space type. Will that take care of the accumulated loads in the attic for modeling?

rkbest ( 2015-08-05 14:29:30 -0600 )edit

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answered 2015-08-05 14:47:08 -0600

David Goldwasser

20415 ●94 ●14 http://www.openstudio.net/

updated 2015-08-05 14:47:26 -0600

First see if you have a default space type assigned to your building. You can do this by selecting "My Building" in the facility tab as shown on the facility tab documentation.

If you do have a default space type then all spaces will inherit internal loads from this space type unless they have a space type assigned directly to them. You can directly assign a space type to a space by selecting the space you want to assign the empty space type to, then go to "My Model" in the right pane, and drag the empty space type to the "Space Type" drop zone. Now you should only see loads from the empty space type. If you want to add infiltration to that space type then go to the "Space Type" tab and drag in a "Space Infiltration Design Flow Rate" object from the library.