Retail Environments - March 2016

needed to make the buildings compliant
with that standard:
• Improving the building envelope
• Reducing the lighting power density
• Incorporating skylights and day-
light harvesting

• Increasing the energy efficiency of
the packaged rooftop HVAC units
The cost of those ECMs was approx-
imately $127,000. With the computer
model showing a projected annual
energy savings of $14,278, the result
was an 11.2% ROI and an 8.9-year
simple payback.

The medium-impact package included the first three ECMs recommended in the low-impact package and replaced the packaged rooftop HVAC units with better space- and water-heating technologies, including:

• A direct expansion (DX) dedicated
outdoor air system with energy
recovery
• A high-efficiency DX packaged
variable-air-volume system with
hot-water reheat

• A high-efficiency condensing
boiler to provide hot-water reheat
The capital cost of the medium-
impact ECM package was approxi-
mately $221,300 with an annual
energy savings of $39,224. This pro-
duced a 17.7% ROI and a 5.6-year
simple payback.

The high-impact package included all measures from the low- and medium-impact packages except for the rooftop units, and it added water-source heat pumps and variable-speed fans as a final ECM. But with a predicted capital cost of $294,485, the high-impact package was the most expensive. It offered an annual energy savings of $14,958, just $500 more than that of the low-impact package. The projected ROI at

5% and the 19.7-year simple payback
made this the least-attractive option.
A worthwhile exercise

The medium-impact package was found to be the best option. While the modeled store was in the Midwest, the package could be tailored to fit other climate zones. With a predicted energy savings of almost $40,000 per year, the package was projected to save more than $750,000 annually if implemented at the 19 planned stores.

This energy-modeling exercise gave Bergmeyer a chance to thoroughly analyze the impact of ECMs on both energy use and cost savings for the client’s prototype store design. Plus, it showed that using energy modeling to develop an energy optimization strategy is a worthwhile investment in itself.