World Savings Center, constructed in 1982, was chosen for the installation of a new Energy Management System (EMS) and other upgrades, including a building-wide lighting retrofit, a carbon monoxide monitoring system, and the installation of Variable Frequency Drives (VFD) on various pumps and fans. These additions were designed by next>edge as part of the overall energy efficiency enhancement for the property.

The Direct Digital Control (DDC) EMS controls all heat pumps, lighting, cooling towers, load shedding, start/stop timing, and condenser water temperature. VFD's on various pieces of equipment enable the EMS to optimize the performance of the overall building systems even further.

A typical next>edge lighting retrofit was accomplished by replacing T-12 light tubes with T-8 light tubes and installing electronic ballasts. The incandescent and fluorescent exit signs were replaced with LED exit signs that use only 2 watts instead of 10 watts per fixture. Occupancy sensors were also installed throughout the building, reducing lighting energy in unoccupied areas. The carbon monoxide monitoring system provides the fan systems with more sophisticated control, allowing improved ventilation to the parking garage while reducing excess energy consumption.

In addition to all the lighting and mechanical upgrades, many no cost/low cost measures were implemented by next>edge to reduce energy consumption:

		Demand-side management programs including EMS with next>edge's advanced EMS sequencing (AES) control to monitor the peak kilowatt demand and monthly reviews of peak demand.
		Reducing simultaneous heating and cooling. This was largely achieved by spreading the load over time, using optimal start strategy and allowing the EMS to work for us.
		Pre-cooling and pre-heating the building at night during low energy use/cost times.

next>edge installed a new Energy Management System (EMS) and replaced four inefficient air-cooled condensers as part of a comprehensive energy enhancement program.

next>edge's energy enhancement strategy at this building was designed to implement a full economizer cycle, providing maximum outside air, while minimizing required compressor energy consumption. In addition, each 60-ton compressor was replaced with a unit capable of staging the operation of two 10-ton and four 15-ton compressors. next>edge also installed high-efficiency scroll compressors. Additionally, next>edge conducted a modified lighting retrofit by replacing approximately 4,500 T-12 light tubes with T-8 light tubes. Electronic ballasts were previously installed.

The EMS controls the modulation of the outside air economizer, staging of compressor, load shedding, start/stop timing, static pressure (through variable speed drive control) and expansion valve sequencing. The system also controls the reset points on supply, return and outside air.

The simple payback for these initiatives is approximately 3.5 years with a marked increase in tenant satisfaction and comfort as well as a positive impact on the environment by reducing overall electrical consumption. The combined impact of next>edge's energy efficiency solutions resulted in a decreased usage of approximately 300,000-kilowatt hours annually.

8383 Wilshire, constructed in 1971, received a new Energy Management System (EMS), a building-wide lighting retrofit, carbon monoxide monitoring system and the installation of Variable Frequency Drives (VFD) on all major equipment, including one of the two 700-ton centrifugal chillers.

next>edge uses the EMS software to monitor and control all fan operation, chiller loading, load shedding, start/stop timing, and condenser water temperature set points. The system also monitors the highly efficient variable flow pumps, high efficiency motors and all direct digital controls. Arden reset the supply air duct static pressure set points on a floor-by-floor basis. The resulting horsepower reduction and associated energy savings have been very significant.

next>edge retrofit the building lighting by replacing T-12 light tubes with T-8 light tubes and installing electronic ballasts. All incandescent and fluorescent exit signs were replaced with LED exit signs that use only 2 watts per fixture, compared to 10 watts used by incandescent exit lights. next>edge also installed

occupancy sensors throughout the building, reducing lighting energy in unoccupied areas.

The carbon monoxide monitoring system provides the fan systems with better control, allowing the systems to provide better ventilation to the parking garage, while reducing excess energy consumption.

In addition to all the lighting and mechanical upgrades, next>edge implemented many no cost/low cost measures to reduce energy consumption. These include:

5200 Century was constructed in 1982. After undergoing a next>edge energy audit and retrofit process, this building has become one of the most energy efficient buildings in the United States. Some of the observed performance levels here are beyond even the highest scoring ENERGY STAR buildings.

Historically, this facility always had an air conditioning capacity problem. The issue was twofold – the main supply airshafts were undersized and the installed chillers were short on capacity. As a result, the building could only be partially leased and many existing tenants were considering a departure due to the lack of satisfactory comfort cooling. Many “high-tech” tenants could not even consider the building due to severe constraints on allowable equipment densities. The existing system simply could not serve today’s typical tenant – a company having at least one personal computer per employee, computer servers, specialty lighting and other needs.

While a typical office building would have chiller capacity of 400 square feet per ton and fan capacity of 1.0

cfm per square foot, this building had 500 square feet per ton and only 0.75 cfm per square foot. The main airshafts could not practically be enlarged, so therefore an innovative solution was required to solve this problem. Previously, comfort was achieved by limiting tenant equipment and running the air conditioning systems for extended hours to “catch up” with the building load.

next>edge retrofitted the building with a new low temperature air distribution system. In order to reach supply air temperatures down to 45 degrees Fahrenheit, a low-temperature, variable frequency drive centrifugal chiller and an 8-row, all copper cooling coil were installed, along with all new central plant equipment and controls. More than 10 variable frequency drives were installed, and the entire air distribution system was replaced with low temperature components.

The greater surface areas available for heat transfer in the new equipment has enabled next>edge to run the refrigeration machines at more optimal condenser and evaporator temperatures. Very accurate flow meters and kW monitoring equipment are utilized to optimize overall system efficiency in kW/ton. Since completing the optimization process, we have consistently logged efficiencies for the entire HVAC system of less than 0.75 kW/Ton. To put this figure in perspective, typical chillers by themselves operate at 0.75 kW/Ton, whereas in this instance we have an entire HVAC system – pumps, fans, cooling tower and chillers – consuming 0.75 kW/Ton. A typical number for an HVAC system is 1.5 kW/Ton or more.

next>edge completed a full building lighting retrofit at the same time that the mechanical upgrades were performed. T8 lamps, electronic ballasts, reflectors and occupancy sensors were installed throughout the site.

In addition to all the lighting and mechanical upgrades, next>edge completed an intensive project commissioning process. More than 50% of the energy savings produced by this project were achieved during this phase. Some commissioning highlights were: