Reference
Glossary
The terms the rule pages assume. Each definition is written to stand on its own.
- Fault detection and diagnostics (FDD)
- Software rules that read building trend data and flag equipment that is operating outside how it should, then point to the likely cause. Energy Agent runs 96 such rules and prices the ones that waste energy.
- ASHRAE Guideline 36
- ASHRAE’s published high-performance sequences of operation for air-handling systems. Its fault conditions FC01 to FC16 describe common air-handler faults; the AHU-FC rules in this library are aligned with them.
- Energy use intensity (EUI)
- Annual energy use divided by floor area, usually in kBtu per square foot per year. It is the standard way to compare buildings of different sizes and the basis of CBECS benchmarking.
- CBECS
- The U.S. Energy Information Administration’s Commercial Buildings Energy Consumption Survey, a national sample of commercial buildings and their energy use. Pelorus Engineering’s CBECS Explorer benchmarks a building against the 2018 survey.
- Baseload
- The load a building carries when it should be doing the least, typically overnight and on weekends. A high or rising baseload is the single most common controllable energy problem in commercial buildings.
- Delta-T (ΔT)
- The temperature difference between the supply and return of a water loop. Low ΔT means the loop moves more water than the load needs, which raises pumping energy and limits plant capacity.
- Economizer
- An air-handler mode that cools with outdoor air when the outdoor air is cool enough, instead of running the cooling coil. Economizer faults are among the most common and most expensive air-side problems.
- Setback
- Relaxing heating and cooling setpoints when a space is unoccupied so the equipment runs less. Missing or overridden setbacks show up as after-hours operation and weekend-like-weekday load.
- Demand charge
- The part of a commercial electric bill priced on the highest short-interval draw in the month rather than on total energy. A single avoidable peak can cost more than a month of small waste.
- Diagnostic rule
- A rule that surfaces a comfort, reliability or data-quality problem but claims no dollar savings, by design. Seventeen of the 96 rules are diagnostic.
- Cascade suppression
- Folding a downstream symptom into the upstream fault that explains it, so one root cause is not counted several times. The hidden savings still appear on the cause.
- IPMVP
- The International Performance Measurement and Verification Protocol, the standard framework for proving that an energy-saving measure actually saved energy. Energy Agent verifies savings to IPMVP options A, B or C.
- Short cycling
- Equipment starting and stopping far more often than its design allows, usually from a control or capacity mismatch. It wears compressors and chillers and wastes the energy spent on each start.
See these rules run on your building.
Send twelve months of interval data and a BAS trend export. Energy Agent returns a ranked list of what is wasting money, what each item is worth per year at your tariff, and what to do about it.