5 Overlooked and Untapped Energy Conservation Measures
When faced with budget shortfalls and rising expenses, facility managers may feel pressure to reduce operational costs. One approach is to optimize the building equipment to increase efficiency gains which can lead to decreased energy expenses. But finding and diagnosing inefficiencies, or even knowing where to start, can be challenging.
With this in mind, Ryan Lewton, Director of Energy Consulting & Certified Energy Manager at Key2Act, revealed several underutilized energy conservation measures (ECM), identified using root cause analysis, that facility managers can easily check and implement simple changes to quickly start saving energy.
ECM 1: Time of Day Scheduling
One of the easiest and most overlooked ECM is utilizing time of day scheduling (TOD) and night set back (NSB) settings. Both are straightforward energy conservation measures, yet many facilities override or disable these features for a variety of reasons. For example, large buildings may have conflicting schedules with areas, like IT rooms, that require around-the-clock cooling alongside other areas, like administrative offices, that only require daytime cooling. To prevent extended recovery times and comfort complaints, facility managers can install pony equipment for after-hours operation and give local area control to tenants when possible.
Additional preventative and corrective measures facility managers can take include:
· Look for and correct TOD and NSB overrides
· Utilize proper nighttime and unoccupied operations
· Track recovery times and adjust the system equipment serving poorly functioning areas accordingly
ECM 2: Ventilation Rates
Many buildings are over-ventilated and recent, often confusing, guidance around virus prevention has caused facility managers to participate in extreme over-ventilation of their buildings. The effect of over-ventilation is wasted energy resulting in excessive amounts of air to spaces that were already over-ventilated to begin with. The increase in air to the spaces not only increases energy use but can also cause humidity control issues, excessive preheating, and diminished cooling capacity.
Building HVAC equipment, like fixed dampers and clogged flow rings or bars, can also contribute to the problem. By calibrating differential pressure transmitter (DPT) sensors, assessing damper function, and unclogging flow rings and bars, a facility manager is able to improve ventilation rates. The latest ASHRAE ventilation rate requirements should also be consulted and incorporated in any system changes.
ECM 3: Setpoint Limits
While it seems counterintuitive, simultaneous heating and cooling occurs frequently in buildings. Some of the root causes of simultaneous heating and cooling include overlapping heating and cooling setpoint limits, default settings on the BAS system, and no ambient lockouts on reheat.
As a result, facility managers may receive comfort complaints, see a rise in utility budget costs, and notice poor space temperature control. But a simple fix can be instituted by using space temperature control setpoints. By controlling the setpoint, facility managers can improve comfort levels and reduce overall system energy consumption.
ECM 4: Heating Water Reset
Facilities using hot water systems with mixing valves or condensing boilers can implement heating water temperature reset. The common reasons behind equipment and performance inefficiencies consist of poor reheating at terminal devices and excessive burner cycling.
Similar to ECM 3, applying temperature resets can reduce the annual gas consumption for reheating water by 5% to 25%. Measures to improve efficiency can also include:
· Installing a three-way bypass valve in the hydronic loop
· Adding boiler sequencing controls
ECM 5: Chilled Water Reset
A chilled water temperature reset can relieve common issues in the right conditions, such as humidity control, short cycling compressors, and low delta temperature conditions. By pairing chilled water reset with an air-side economizer operation, such as comparative enthalpy, facilities may realize a 1% efficiency gain per degree of temperature reset.
When completing a root cause analysis, we generally come to three conclusions.
1. The reset’s independent variable should correspond to building operations.
2. The max reset point needs to intersect at the balance point of the chiller’s minimum load capacity.
3. The cooling tower resets may require adjustments to keep lift and stop surge conditions.
Optimize Systems for Peak Performance
Continuous monitoring and analytical insights can help your organization reduce utility costs while ensuring optimal tenant comfort. Facility managers can leverage tools, like the BOB energy utility dashboards to find opportunities for savings. Contact us to learn how to unlock additional energy savings using BOB.