The Forgotten Solution

The forgotten solution: maintaining HVAC controls

Forward thinking and creative Professionals are engineering solutions to mitigate global warming and climate change. In the heating, cooling and ventilation sector many Professionals are implementing the use of high efficiency boilers, air conditioners, fans, pumps, variable speed drives, and constructing energy-efficient energy neutral buildings. Automated controls and remote monitoring can help operators check whether equipment follows the intended sequences. Their cost and value depend on the installation, and monitoring alone does not guarantee efficient operation. While the ability to extract energy savings from HVAC systems has increased significantly over the past decade, the retention of those initial design savings has not. Energy performance can drift after installation when schedules, setpoints, sensors or operating conditions change. The amount varies by building and must be established from operating records and a suitable energy-use comparison; fixed loss percentages should not be assumed. There are many reasons for this, such as automated settings placed in manual override, altered business use, but the one most prevalent forgotten solution is the maintenance of the controls system. Without a clear long-term owner for controls performance, responsibility for retaining energy savings can be overlooked. The valued ROI promised at time of purchase as well as environmental stewardship intrinsic to the initial energy conservation program is diminished when priority is solely given to maintaining operation relating to comfort conditions. Knowing and understanding the benefits of managing energy savings systems while providing comfort conditions will ensure the systems function effectively for the long term. The business case for recommissioning should compare the investigation and corrective-work costs with documented opportunities, rather than assume a payback.

What to review in a controls maintenance plan

• Equipment schedules and temporary overrides that were never cleared.
• Sensor readings, calibration and recurring alarms.
• Changes in occupancy, production or space use.
• Trend data and utility records, interpreted with operating conditions in mind.

Explore DDC controls and building automation, HVAC energy management and planned maintenance. An assessment can identify which changes deserve further investigation.

Three checks that make the forgotten solution actionable

1. Compare the intended sequence with actual operation

Start with the documented operating sequence and current building use. Check whether equipment schedules still match occupancy or production. A temporary override may have been necessary during a fault, but it should have an owner and a review point rather than remain in place indefinitely.

Ask the facility team where comfort complaints, recurring alarms or manual interventions occur. Those observations can identify useful areas for investigation. They are not proof of a particular energy loss. Review operating records before deciding whether the issue is a control setting, a sensor, a maintenance problem or a changed requirement.

2. Maintain the information used by the controls

Control decisions depend on measurements and available feedback. Review sensor readings and calibration where appropriate, together with actuator response and recurring alarms. A plausible value on a screen is not necessarily a verified measurement. Record what was checked and under which operating conditions.

Trend data can help reveal equipment running outside the expected schedule or systems responding differently to similar conditions. Interpreting those trends requires context, including weather and changes in building use. The forgotten solution is therefore an ongoing review process rather than a one-time software setting.

3. Assign responsibility and evaluate proposed changes

Identify who owns the operating sequence, who approves changes and who reviews performance after a repair or occupancy change. Preserve the documentation so future technicians understand why settings were selected. Clear responsibility helps keep comfort, process requirements and energy objectives from being treated as unrelated tasks.

Where an improvement is proposed, define the scope, cost and verification method before promising a return. Compare equivalent operating periods where possible and record the limits of the data. For broader technical references, see ASHRAE standards and guidelines; their availability does not validate any particular savings claim.