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cooling as well as fresh air to all floors and atrium. Variable air volume systems (VAV) were part of the
design strategy to save energy when the building is not fully occupied.
Figure 2. Case study building’s floor plan and the façade view
3.2. Energy audit and POE monitoring
ASHRAE Energy Audit Level 1, which is ‘Site Assessment or Preliminary Audits, was carried out
to assess the case study building. Energy audits were taken a whole building approach by examining
the building envelope, building systems, operations and maintenance procedures, and building
schedules. From the whole building audits provided the most accurate picture of energy usage and
energy saving opportunities at the case study building. Monitoring of POE data also conducted via
walkthrough inspections and the monitoring exercise by portable and fixed unit measuring data logger
and devices. Installing the data loggers, every floors were installed to measure temperature, RH, CO 2 ,
PM 2.5, PM 10 and TVOC. Both the energy audit and POE were used for identifying performance gap,
maintenance problems and other aspects that may have negative impacts on indoor environmental
quality. The results and findings from energy audit and POE were used to calibrate energy simulation
model to rebuild current scenario in simulation software and to define energy performance gap in the
case study building.
3.3. Dynamic building energy simulation
A dynamic building energy model was developed for the case study building based on energy audit
and POE information. The simulation model was calibrated with the actual performance including indoor
environmental condition and HVAC operation. To define the energy performance gap in case study
buildings, a four different simulation models was developed and each of the models was named as
baseline model, Abu Dhabi code, as‐designed model and in‐use model and its specifications and input
data were shown in the table 2. The input data and building specifications for as‐designed model and in‐
use model were based on the energy audit and POE data analysis.
Table 2. Simulation models’ specifications and input data
Baseline model
Abu Dhabi code
As‐designed model
In‐use model
Wall 0.705 (W/m²K) 0.329 (W/m²K) 0.537 (W/m²K) 0.537 (W/m²K)
Roof 0.360 (W/m²K) 0.329 (W/m²K) 0.403 (W/m²K) 0.403 (W/m²K)
Floor
Window
HVAC
Cooling Set Tem
1.986 (W/m²K) 1.823 (W/m²K) 1.423 (W/m²K) 1.423 (W/m²K)
6.81 (SHGC 0.25) 2.2 (SHGC 0.25) 2.2 (SHGC 0.25) 2.2 (SHGC 0.25)
Package Rooftop DX, Package Rooftop DX, Package Rooftop DX, Package Rooftop DX,
CAV ( System 3) CAV VAV CAV**
24°C (28°C*) 24°C (28°C*) 24°C (28°C*) 21°C **(23°C*)
Airtightness 0.6 ACH 0.6 ACH 0.6 ACH 1.0 ACH**
Lighting 9.7 W/m² 9.7 W/m² 9.7 W/m² 9.7 W/m²
* Cooling setback temperature
** Input data from energy audit and POE studies
Using Energy Audit with POE Study to Reduce Energy Performance Gap in an Office Building in UAE
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