A commercial building may only be occupied for part of the day, but that doesn’t necessarily mean its energy consumption stops when everyone leaves.

Heating, cooling, ventilation and other building services can continue operating overnight, at weekends and during holidays. Sometimes this operation is necessary. In other cases, equipment may simply be running because schedules and controls no longer reflect how the building is actually used.

A Building Energy Management System can help facilities teams understand what happens after normal working hours and identify unnecessary energy consumption.

Are Your Schedules Still Accurate?

BEMS schedules are often configured around expected occupancy patterns. However, those patterns can change.

Tenants move, departments change their working hours and organisations introduce hybrid working. Cleaning and maintenance schedules may also change over time.

If the BEMS isn’t updated accordingly, plant could continue operating according to schedules created when the building was being used very differently.

Regular schedule reviews can help ensure services operate when they are required and switch back or shut down when they’re not.

Look for Equipment Running Overnight

Data allows facilities teams to look beyond instantaneous readings and understand how equipment operates over longer periods.

For example, data may reveal an air handling unit operating throughout the night, heating continuing long after occupants have left or cooling equipment starting much earlier than expected.

Once unusual operation has been identified, engineers can investigate why it is happening.

Don’t Forget About Overrides

Manual overrides can be particularly relevant to out-of-hours energy consumption.

An engineer or facilities manager may temporarily override a piece of equipment for maintenance or to respond to a comfort issue. If that override isn’t subsequently removed, the equipment could continue operating regardless of its normal schedule.

Regularly reviewing overrides can prevent temporary changes becoming permanent sources of unnecessary energy use.

Understand What Really Needs to Run

Reducing out-of-hours consumption doesn’t mean simply switching everything off.

Some buildings contain critical areas or equipment that need continuous environmental control. Frost protection, server rooms, security requirements and specialist operations may also require certain systems to remain active.

The objective is to understand what genuinely needs to operate and ensure everything else is controlled appropriately.

See What Your Building Does When Nobody Is There

At Concord, we help clients use BEMS data to understand when and why their building services are operating.

By reviewing schedules, data, overrides and control strategies, it is possible to identify unnecessary out-of-hours operation and make adjustments without compromising building requirements.

Sometimes, understanding how a building performs when it is almost empty can reveal just as much as monitoring it during the busiest part of the day.

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