ENERGY SAVINGS IN TUNNEL VENTILATION
REDUCE UNDERGROUND VENTILATION ENERGY COSTS WITH SWEDFAN
SWEDFAN is committed to reducing energy consumption and operating costs in tunneling and underground construction projects.
By combining high-pressure axial tunneling fans with frequency inverters and project-specific ventilation system design, SWEDFAN helps customers optimize airflow and reduce unnecessary electricity consumption.
In drill and blast tunneling, ventilation requirements change throughout the construction cycle. By adjusting fan speed to actual operating conditions, significant energy savings can be achieved without compromising required ventilation performance.
HOW FREQUENCY INVERTERS REDUCE FAN ENERGY CONSUMPTION
Frequency inverters, also known as variable frequency drives (VFDs), allow the speed of underground ventilation fans to be adjusted according to airflow requirements.
Fan power consumption is approximately proportional to the cube of fan speed under comparable operating conditions. For example, reducing fan speed by 50% results in:
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Approximately 50% lower airflow.
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Approximately 87.5% lower theoretical fan power consumption.
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Approximately 85% lower power consumption under the practical assumptions used in SWEDFAN's calculation example.
This makes variable speed control an effective way to reduce electricity consumption when full ventilation capacity is not required.
OPTIMIZING VENTILATION DURING DRILL & BLAST TUNNELING
Ventilation requirements vary during the different stages of a drill and blast tunneling cycle.
Blasting and Fume Removal
Immediately after blasting, fans operate at full speed to remove blasting fumes as quickly as possible.
Mucking Operations
During mucking, high ventilation capacity is typically required to remove diesel exhaust from underground trucks and loaders.
Scaling, Drilling and Charging
During these stages, ventilation requirements may be lower. Fan speed can therefore be reduced where site conditions and applicable safety requirements permit.
SWEDFAN's experience indicates that, in suitable drill and blast projects, fans may operate at reduced speed for approximately 50–60% of the construction cycle.
By matching ventilation capacity to actual demand, project operators can significantly reduce energy consumption and operating costs.
Energy Savings Example
52% LOWER ENERGY CONSUMPTION
Consider a tunnel ventilation installation with two 110 kW fans operating at an assumed 80% electrical load at full speed.
Conventional operation – full speed throughout the cycle
6.5 hours × 220 kW × 80% = 1,144 kWh
Variable speed operation
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2.5 hours at full speed: 440 kWh
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4 hours at half speed, consuming 15% of full-speed power: 106 kWh
Total: 546 kWh
Energy saved per cycle: 598 kWh
Reduction in energy consumption: approximately 52%
This example demonstrates the potential of frequency-controlled tunnel ventilation to reduce electricity consumption during a typical drill and blast work cycle.
LOWER ENERGY COSTS THROUGHOUT THE PROJECT
Energy-efficient tunnel ventilation can deliver substantial financial savings over the lifetime of an underground construction project.
Using the example above, with 15,000 operating hours and an electricity price of USD 0.15/kWh, the estimated electricity cost savings would be approximately USD 207,000 over the project period.
Actual savings depend on fan selection, operating schedules, electricity prices, ventilation requirements and project conditions.
SWEDFAN helps customers evaluate ventilation equipment and system design to improve energy efficiency and reduce long-term operating costs.
ENERGY-EFFICIENT UNDERGROUND VENTILATION SYSTEM DESIGN
Achieving energy-efficient tunnel ventilation requires more than selecting the right fan.
Correct fan sizing, ventilation duct selection, airflow calculations and variable speed control all contribute to overall system performance.
SWEDFAN provides integrated underground ventilation solutions, combining high-pressure axial fans, flexible ventilation ducting, frequency inverters and project-specific system design.
Our goal is to help customers achieve reliable ventilation performance while minimizing unnecessary energy consumption.
FREE TUNNEL VENTILATION SYSTEM DESIGN
Optimize Your Tunnel Ventilation and Reduce Energy Costs
Planning a tunneling or underground construction project? Let SWEDFAN help you design an energy-efficient ventilation system tailored to your project's requirements.
The more information you provide, the more accurately we can evaluate your project.
Tunnel Ventilation Project Questionnaire
Please complete the form with your project details, and our engineers will provide a free preliminary ventilation system design, including recommendations for fan selection, airflow requirements and potential energy savings.