TAN-S 5.5 VSD
5.5 kW · 19 CFM @ 10 barCompact PM-VSD option for suitable workshop and light-industrial duties.
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AIR COMPRESSOR BUYING GUIDE
Is a Variable Speed Compressor Worth the Extra Cost?
For UK workshops and manufacturers with changing air demand, a correctly sized variable speed compressor could reduce electricity costs. But is it the right investment for your business?
Explore Potential Savings → Request a Quotation →
A VSD compressor can be a smart investment, but only when its output and operating range suit the way your site actually uses air.
Fixed-speed machines may be the more economical choice where demand is steady. If production demand rises and falls, however, variable speed drive (VSD) control may reduce wasted electrical power and shorten the payback period. The starting point is understanding your current operating profile, not simply choosing the newest technology.
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UNDERSTANDING THE DIFFERENCE
What Does a Variable Speed Air Compressor Do?
A conventional fixed-speed rotary screw compressor generally runs at a set motor speed when loaded. When air demand falls, it may continue running unloaded before stopping, depending on the controls and system configuration.
A variable speed drive compressor adjusts motor speed to follow compressed air demand within its designed operating range. This can reduce inefficient unloaded operation and help stabilise system pressure.
VSD is not a guarantee of lower running costs. A machine operating near full output for almost every shift may see less benefit than a workshop with substantially changing demand.
CHOOSING THE RIGHT TECHNOLOGY
Fixed Speed vs Variable Speed: Which Is Better?
A VSD Compressor May Suit You If...
- Air demand varies throughout the working day.
- Different production lines or air tools run at different times.
- Your existing compressor spends a lot of time unloaded.
- You have long annual operating hours and want to examine energy savings.
- You need a replacement matched to measured air demand rather than just the old motor rating.
Fixed Speed May Make More Sense If...
- Air demand is consistently close to the compressor's full output.
- Operating hours are low and an energy saving would take longer to repay the investment.
- The installation has a stable, predictable duty cycle.
- The additional capital cost is not justified by a measured running-cost comparison.
- A different compressor type, such as a piston machine, better suits occasional use.
Don't automatically replace like-for-like.
An existing 11 kW compressor does not automatically mean your business needs another 11 kW machine. Air demand, working pressure, duty cycle and future capacity requirements should all be reviewed.
PUTTING A VALUE ON EFFICIENCY
How Much Could a VSD Compressor Save?
For illustration, assume a workshop uses compressed air for 2,000 hours per year and pays 25p per kWh for electricity. If a properly selected replacement reduces its measured average electrical input from 10 kW to 8 kW, the annual comparison would look like this:
| Example metric | Existing system | Replacement system |
|---|---|---|
| Average electrical input | 10 kW | 8 kW |
| Annual operating hours | 2,000 | 2,000 |
| Annual electricity usage | 20,000 kWh | 16,000 kWh |
| Electricity cost at £0.25/kWh | £5,000 | £4,000 |
ILLUSTRATIVE PAYBACK
What About the Extra Purchase Cost?
In this example, electricity savings are £1,000 per year. If the VSD machine costs £1,500 more than an otherwise suitable fixed-speed option, the simple energy payback would be 18 months.
That is only a calculation example, not a Tanair product savings promise. A proper comparison should include capital costs, servicing, installation, operating conditions, and the actual electrical consumption of the alternatives.
Try Our ROI Calculator →Example Results Only
4,000 kWhillustrative annual electricity reduction
£1,000illustrative annual electricity saving
SIMPLE ENERGY PAYBACK18 months
Important: Figures above are hypothetical inputs used to explain the calculation, not measured results from a specific fixed-speed or Tanair VSD model. Actual savings vary with load profile, tariff, installation and operating conditions.
EXPLORE OUR RANGE
Tanair TAN-S Permanent Magnet VSD Compressors
The Tanair TAN-S PM-VSD range includes the following 415 V three-phase machines. Rated airflow and operating requirements should be confirmed when selecting a model for your application.
TAN-S 7.5 VSD
7.5 kW · 32 CFM @ 10 barFor variable compressed-air demand in workshop and manufacturing applications.
View Compressor →TAN-S 11 VSD
11 kW · 46 CFM @ 10 barMedium industrial applications where air usage changes during production.
View Compressor →TAN-S 22 VSD
22 kW · 112 CFM @ 10 barHigher-output option for industrial and manufacturing air systems.
View Compressor →Only have a 230 V supply?
Single-phase variable-speed solutions, including PhaZair, may be suitable for some applications. Ask us to compare the available options against your airflow and electrical requirements.
LOOK AT THE WHOLE INSTALLATION
Efficiency Is About More Than the Compressor
What We Review
- Air demand during busy and quiet periods
- Existing loaded and unloaded running
- Operating pressure and pressure drop
- Potential air leaks
- Receiver capacity, air treatment and pipework
- Current energy tariff and running hours
How We Can Help
- Compressor sizing and selection
- Compressed-air energy audits
- Leak detection and pipework improvements
- Dryers, receivers and filtration
- Installation and commissioning
- Ongoing servicing and maintenance
The Right Compressor, Not Just the Newest One
Our aim is to identify equipment that makes operational and financial sense for your business. That might mean a PM-VSD compressor, a fixed-speed unit, or improvements to the system you already have.
Compressed Air Systems UK — home of the air compressor that pays for itself.
YOUR QUESTIONS ANSWERED
Variable Speed Air Compressor FAQs
Are variable speed air compressors cheaper to run?
Often, when air demand fluctuates and the compressor is correctly sized. Savings depend on its operating range, actual demand and the system it replaces.
Is a VSD compressor always better than fixed speed?
No. Where demand is consistently high, a properly selected fixed-speed compressor may provide better value. The right answer comes from comparing actual operating requirements.
How long does it take for a VSD compressor to pay for itself?
There is no universal payback period. Divide the additional project cost by the estimated annual net saving to calculate a simple payback, then review maintenance, installation and other lifecycle costs.
Can a variable speed compressor operate all day?
Industrial VSD machines can be suitable for continuous operation when specified and installed within their design limits. Correct sizing, ventilation and servicing remain important.
Do I need three-phase electricity for a VSD compressor?
Not always. The TAN-S models shown here use a 415 V three-phase supply, but suitable 230 V single-phase VSD alternatives are also available.
Is a VSD Compressor Worth It for Your Business?
Tell us about your current compressor, working pressure, operating hours and how your air demand varies. We can help you assess the likely running costs and select the right equipment.
Request a Compressor Quotation → Call 0121 753 3330Energy-saving information: Savings and payback figures are estimates and depend on the individual site, demand profile, equipment, electricity tariff and operating conditions. A technical assessment should be completed before investment decisions are made.