Clarification of EnergyPlus OtherEquipment Impact on HVAC Loads

Hello,

I'm a bit confused regarding the wording of EnergyPlus's description for OtherEquipment. The part that confuses me is:

"Note, too, that this object does not have an end-use component - gains or losses do not show up in the bottom energy lines (except as influencing overall zone gains or losses)."

Does this mean that it will only affect the overall zone gains and losses in the output with no impact to HVAC loads (energy use) or will the affect on zone balance then eventually affect HVAC loads for the respective zone?

Thank you, Justin

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JustinShultz

asked 2015-06-29 18:01:08 -0500

4.4k

__AmirRoth__

updated 2015-07-12 10:23:44 -0500

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They will affect the HVAC loads and zone balance, but are not metered energy uses themselves. For example, if you have the following Lights Object:

Lights, Zone1 Lights, Zone1, Always On, LightingLevel, 100;

Run for 1 year, the heat produced by the lights will affect the HVAC equipment and zone temperatures, AND you will have 876 kWh reported in the End Uses summary.

If you have the following OtherEquipment object:

OtherEquipment, Zone1 Other Equipment, Zone1, Always On, EquipmentLevel, 100;

Run for 1 year, the heat produced by the OtherEquipment object will affect the HVAC system and zone heat balance, but the energy use will not be reflected in the End Uses summary.

OtherEquipment is useful for modeling, well... other equipment - equipment that is not metered at the building. Maybe you're modeling an indoor electric dirtbike track, and everyone brings their own fully-charged bikes. The energy the bikes use as they discharge their batteries inside the building degrades to heat and effects the zone heat balance, but that energy was provided elsewhere... other equipment.

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kwalkerman

answered 2015-06-30 09:44:19 -0500

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Another valuable application for OtherEquipment is to add some load during sizing calculations. The load can be negative and provide cooling to the zone during only winter design days to help work around issues that can occur when reheat coils are coming out too small (and then lead to unmet hours).

Archmage (2015-07-01 14:52:45 -0500) edit

Thanks you for both the responses. Very helpful! As a counterpart, is there a component that can be used to add or subtract end-use energy?

JustinShultz (2015-07-09 08:04:44 -0500) edit

ExteriorEquipment can add energy without affectiong any zone thermal loads, but I cannot think of an easy way to subtract energy use in the usual energy metering. There are custom meters that can deprecate out selected end uses from the total.

Archmage (2015-07-14 05:57:48 -0500) edit

With recent versions of EnergyPlus, you can use the OtherEquipment object to subtract or add energy use, as the object now has a Fuel Type field. If you also set the Fraction Lost field to 1.0, there will be no effect on zone thermal loads.

shorowit (2022-04-20 03:28:00 -0500) edit

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Clarification of EnergyPlus OtherEquipment Impact on HVAC Loads

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Clarification of EnergyPlus OtherEquipment Impact on HVAC Loads