Energy savings and return on investment
Turn Better Airflow into Lower Building Operating Costs.
MegaFan HVLS systems can reduce energy waste by returning trapped roof heat to the occupied zone, improving the distribution of conditioned air and operating only when the building requires airflow.
Use the interactive calculator to explore possible annual savings, then request a project-specific assessment using the real building, energy consumption, tariffs, operating hours and proposed fan system.
In a high building, useful heating energy can collect close to the roof while the occupied working zone remains below its target temperature. During warmer periods, conditioned or fresh air can also be poorly distributed across a large space.
MegaFan systems focus on moving the air already being heated, cooled or supplied so that a larger proportion reaches the areas where it is actually required.
The financial case should then compare the energy or operating cost avoided with the electricity, maintenance and capital cost introduced by the proposed airflow system.
Winter Destratification
Return warm roof-level air towards the occupied zone so that less heater power or operating time may be required to maintain the target working temperature.
Summer Air Movement
Improve perceived comfort and help distribute conditioned or incoming air across occupied areas more effectively, subject to measurement and verification before changing HVAC settings.
Controls & Scheduling
Operate fans at the speed, time and location actually required rather than running every device continuously, helping reduce unnecessary operating hours.
Measure & Verify
Use energy bills, meter data, operating hours and temperature measurements to confirm whether the expected saving is being achieved after the system is installed.
The examples below show what 32%, 40% and 45% would represent against different levels of relevant annual heating spend. These are simple gross illustrations before fan electricity, project cost, maintenance and other adjustments.
| Relevant Annual Heating Spend | 32% Gross Illustration | 40% Gross Illustration | 45% Gross Illustration |
|---|---|---|---|
| £10,000 | £3,200 | £4,000 | £4,500 |
| £25,000 | £8,000 | £10,000 | £11,250 |
| £50,000 | £16,000 | £20,000 | £22,500 |
| £100,000 | £32,000 | £40,000 | £45,000 |
| £250,000 | £80,000 | £100,000 | £112,500 |
Estimate Your Potential Energy Savings & Payback
Enter the figures for your proposed project to calculate an illustrative annual saving, fan running cost and simple return on investment.
Your Planning Estimate
A fan system should not simply be installed and assumed to operate at maximum speed throughout every occupied hour. The airflow requirement can change with temperature, season, occupancy, operating schedules and the part of the building being used.
Appropriate controls allow compatible MegaFan systems to operate at the speed, time and location required. Depending on the selected products, the control strategy can range from straightforward manual speed control through to centralised or automated multi-device operation.
Individual Fan-Speed Control
Adjust compatible fans to the airflow actually required rather than assuming full-speed operation is necessary at all times.
High & Low Temperature Monitoring
Temperature monitoring can support automated operation around conditions at different heights within a building, particularly where winter destratification is being controlled.
Summer & Winter Modes
Compatible automated systems can use different operating strategies for summer air movement and lower-speed winter destratification rather than relying on one fixed fan setting all year.
Weekly Occupancy Schedules
Scheduled operation can match airflow to working periods so equipment is not unnecessarily operated during predictable unoccupied periods.
Zone-Based Operation
Where the final system supports it, separate building areas can be controlled around their own occupancy and airflow requirements rather than treating the whole facility as one zone.
BMS & Modbus Integration
Compatible control systems can interface with wider building-management strategies, allowing fan operation to form part of coordinated temperature and operating controls.
Fire-Alarm Shutdown Input
Supported controller configurations can include a fire-alarm shutdown input so fan operation can be incorporated into the building's required control and safety strategy.
Alarm & Fault Reporting
Monitoring and fault reporting help identify system issues that could otherwise leave equipment operating incorrectly or prevent the intended airflow strategy from being delivered.
Any Questions just Contact Us
- FAQS
Frequently Asked Questions
Energy savings from HVLS fans depend on the building, heating or cooling system, operating hours, controls, energy tariffs and how effectively air is currently being distributed. The potential benefit should therefore be assessed against the actual energy use affected by the proposed system, rather than applying a headline percentage to the whole site.
MegaFan systems can support lower winter heating demand through destratification, improve the distribution of conditioned air, and reduce unnecessary fan operating hours through suitable controls and scheduling. The final ROI should compare the verified or reasonably supported cost saving against fan electricity, maintenance and the installed project cost.
These FAQs explain how energy savings are calculated, what affects the potential payback period, how the University of Liverpool modelling should be interpreted, and why measurement and verification are important before claiming a final saving.
How much can an HVLS fan save?
Savings depend on the building, heating or cooling system, temperature gradient, energy prices, operating hours and controls. The University of Liverpool model indicated approximately 32% heater-power saving at a 12.5 metre apex and 40% to 45% for the 15 to 20 metre cases at an outside temperature of 4°C. These were modelled results, not guaranteed savings for every site.
What exactly did the University of Liverpool study measure?
It used Computational Fluid Dynamics to model airflow and heat transfer in a generic 30 metre by 30 metre warehouse zone. Heater power was adjusted to maintain an average temperature of 16°C at 1.5 metres above the floor with the HVLS fan on and off.
Were the 40% to 45% savings measured in a live warehouse?
No. They were estimates from a computational model. The report explicitly noted assumptions and recommended validation against measurements from a real warehouse. The results must therefore be treated as evidence of potential rather than a guaranteed outcome.
How does destratification reduce heating demand?
Warm air naturally rises and can collect near the roof. An HVLS fan moves that air towards the occupied zone and mixes the temperature layers. When more of the existing heat reaches floor level, the heating system may need less power or fewer operating hours to maintain the target temperature.
Why can taller buildings have a stronger opportunity?
High buildings contain a larger volume above the occupied zone and can develop a greater floor-to-ceiling temperature difference. The Liverpool model found the largest percentage savings in the 15 to 20 metre apex cases, while the 12.5 metre model still showed approximately 32%.
Can HVLS fans reduce summer cooling costs?
Air movement can improve perceived comfort and help distribute conditioned air. This may allow changes to air-conditioning settings or operating hours after the effect has been verified. The saving is highly site-specific and should not be assumed without an assessment.
How should savings be verified after installation?
Compare energy use before and after installation over representative periods, while accounting for weather, operating hours, production levels, occupancy and tariff changes. Sub-metering and recorded high-level and low-level temperatures can improve confidence in the result.