ISO 50001
Energy audit
An energy audit is an inspection and survey of the energy flowing through a building, process or system, and of how much of that input could be removed without anyone noticing except the finance department.
The building survey records the envelope — walls, ceilings, floors, doors, windows — measuring the area and thermal resistance of each element, along with the rate at which air infiltrates through it. Both are strongly affected by construction quality and the state of seals and weatherstripping. Professional equipment such as blower doors and infrared cameras makes the invisible parts visible. The audit also assesses the condition and efficiency of heating, ventilation, air conditioning and controls.
You receive a written report estimating energy use against local climate data, thermostat settings, solar orientation and roof geometry, together with the modelled effect of each suggested improvement. Accuracy improves considerably when one or two years of billing history is available, since consumption can then be calibrated against heating and cooling degree-day data from actual weather records.
Some of the largest effects on energy use are behavioral, so for occupied buildings we usually interview the people who use the space. The objective is not only to list where energy goes, but to rank the interventions from most to least cost-effective — while keeping comfort, health and safety intact.
Buildings may also qualify for energy efficiency grants from government programs and international donors, and the audit report is normally the document those applications are built on.