How Improper Flow Control Increases HVAC Energy Bills (And How to Fix It)

Why HVAC Energy Bills Are Higher Than Expected

When HVAC energy bills rise, the first reaction is often to blame the chiller, upgrade equipment, or increase pump capacity. In many buildings, none of these actually solve the problem.

The real issue is usually how water moves through the system.

Improper flow control causes some circuits to receive more water than required while others struggle to meet demand. To compensate, pumps run harder and chillers stay on longer consuming more electricity without improving comfort.

This is why buildings with well-sized equipment still face:

• Unexpectedly high energy bills

• Inconsistent temperatures across zones

• Systems that seem to “work” but never efficiently

Before investing in new equipment, it’s critical to examine flow control. In many cases, correcting flow distribution delivers faster and more cost-effective energy savings than replacing major HVAC components.

What Improper Flow Control Looks Like in Real HVAC Systems

Improper flow control doesn’t always show up as a system failure. More often, it appears as a collection of small, recurring issues that get treated as “normal.”

Common Signs on Site

• Some areas cool or heat faster than others

• Persistent hot and cold zones

• Noisy pipes, valves, or pump cavitation

• Pumps operating at higher speeds than designed

• Frequent setpoint adjustments by occupants or operators

What’s Actually Happening

• Water follows the path of least resistance

• Circuits closer to the pump get excess flow

• Distant circuits are under-supplied

• Controls try to compensate by increasing the runtime

Over time, these imbalances worsen. What starts as uneven comfort slowly turns into higher energy use, mechanical stress, and rising operating costs without any real improvement in performance.

How Poor Flow Control Directly Increases Energy Consumption

When flow is not controlled correctly, HVAC systems compensate by using more power.

Where the Extra Energy Goes

• Over-pumping: Pumps run at higher loads to push water through imbalanced circuits

• Inefficient heat transfer: Low or uneven flow reduces coil performance

• Longer chiller cycles: Systems stay on longer to reach set temperatures

• Unstable controls: Temperature fluctuations trigger unnecessary responses

The Result

Higher electricity consumption without improved comfort.

System Area	Poor Flow Control	Proper Flow Control
Pump energy	High	Optimised
Chiller runtime	Long	Shorter
Comfort	Inconsistent	Stable
Energy bills	Higher	Reduced

Correcting flow often delivers noticeable energy savings without changing major equipment.

How Flow Control Valves Fix the Problem

Improper flow control isn’t corrected by increasing pump speed or lowering temperature setpoints. It’s fixed by regulating how water moves through the system.

Role of Flow Control Valves

• Balancing valves regulate flow at each circuit to match design values

• Digital balancing valves improve accuracy and speed during commissioning

• PICVs maintain a constant flow under changing pressure conditions

What Correct Flow Control Achieves

• Restores uniform distribution across AHUs and FCUs

• Reduces pump head pressure

• Improves heat transfer efficiency

• Stabilises temperatures across zones

In many buildings, correcting flow distribution delivers immediate improvements in comfort and measurable reductions in energy use without modifying major HVAC equipment.

Practical Steps to Reduce Energy Bills Through Better Flow Control

Reducing HVAC energy bills doesn’t always require new equipment. In many cases, it starts with fixing the flow.

What to Do

• Review flow control during energy audits not just equipment sizing

• Balance the system instead of increasing the pump speed

• Match valve type to building size and load behaviour

• Rebalance the system every 1–2 years as usage changes

Key Takeaway

Improper flow control quietly increases energy costs every day.Correcting it is one of the fastest and most cost-effective ways to improve HVAC efficiency while also extending equipment life and improving comfort.