Low kWh

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I have been learning how to use eQuest by modeling this particular building. I feel like I've modeled the control strategy fairly accurately along with all the right equipment. The model is returning kW numbers that are right in line with an average of the last two years billing data, but the kWh figures are really low. I was wondering if anyone had the time to look over my model and give me some insight. Here are the basics:

* It's a two story building with 6 package units. 4 units take care the perimeter cooling and heat (1 unit for 2 exterior walls on each floor) and two 60 ton units for the core of each floor that are cooling only. The perimeter is only 5ft deep and there are no walls dividing the perimeter from the core

* I modeled the core as one giant zone instead of the 20 VAV zones it actually is for simplicity sake. I determined what the end use percentages for that zone were and put them in

* The HVAC is controlled by a time clock set for 5am - 7pm every weekday, excluding holidays. It doesn't come on outside of this time

* The HVAC supply fans turn on and run constantly regardless of VAV position

* The VAV box is set to 10% minimum. When the zone reaches a boundary it opens to 100%, when the zone is satisfied it closes back down to 10%. I don't think this is possible to model, so I'm sure the model will show less kWh partially because of this

* The HVAC uses a 55 degree supply temp with a 13 degree reset

* Min economizer is 10%

Any insight would be appreciated.

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Travis Rhodes's picture
Joined: 2011-09-30
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