Compressed Air versus Blower Systems

6/27/2017

If your business uses compressed air to clean, dry, or cool, your air system may not be as efficient as you think – in fact, the worst offenders are less than 10% efficient. For many applications, it is advantageous to convert to a blower based air system which leads to long term cost savings.

Blow-off of water, dust, coolant and other contaminants, drying, cooling, and heating may all be achieved using either compressed air or blower operated systems; there are several factors to consider when choosing the best system for any application utilizing air. Each factor carries varying weight depending on the application specifics and the existing infrastructure.

FACTORS

1. Energy cost
2. System cost
3. Maintenance and operating cost
4. Application particulars
5. Availability of electricity
6. Space and weight
7. Noise considerations

1. ENERGY COST

Blower operated systems, particularly for continuous flow applications, are almost always the more energy efficient choice. Some blower installations can reduce energy costs up to 80% over previous compressed air systems. When used for the right application, blower bases systems often have an ROI of less than one year due to significant energy savings.

In applications where the need for air is sporadic or in short bursts, the amount of energy consumed by a compressed air system decreases. In these applications compressed air may be the energy efficient solution.

For both system types, implementing a proper control system can further minimize the air and power consumption. TIP: If you're looking to change from compressed air to a blower system or vice-versa, ask your supplier to provide an ROI to see how quickly the change will pay for itself.

2. SYSTEM COST

If an air compressor, with sufficient capacity, and necessary piping are already present in the plant, adding tools is fairly easy and generally low cost up-front. If there is no existing air compressor or not enough capacity available, then the high cost of equipment and installation must be considered.

The initial system cost of a blower will generally be lower than for a compressed air system when there is no excess compressed air capacity available. Blower based systems will require a higher initial capital investment for applications where there is excess compressed air capacity already available. Additionally, government grants are sometimes available to offset the initial cost of a blower system, due to their improved energy efficiency.

3. MAINTENANCE AND OPERATING COST

Both air compressors and blowers need regular maintenance to ensure proper performance. Direct drive blowers have fewer maintenance costs than traditional belt-drive blowers; there are no belts to break which translates to less downtime and lower maintenance costs. The use of a Variable Frequency Drive (VFD) on blower allows it to operate more efficiently and can dramatically reduce energy consumption on blowers. Likewise, use of a PLC system can work to reduce air costs in compressed air based blow-off operations.

It is important not to focus solely on the initial capital investment when selecting a system type. Maintenance and operating costs can differ by a large enough margin that the higher initial costs can be paid back within a year or two of operation.

4. APPLICATION PARTICULARS

Applications that utilize continuous flow favour blower based systems as they are by-far more efficient than compressor based systems. Applications which allow the air to be cycled on and off when needed are better candidates for a compressed air system than those that require continuous or near-continuous flow. The speed and nature of an application must be taken into consideration when choosing a system.

5. AVAILABILITY OF ELECTRICITY

Compressed air system tend to have a centralized air generation location and then send the air to the required locations through a network of pipes. Blower bases systems tend to generate the air close to the location that requires it. As a result, depending on availability of power in your plant, one system may be preferred.

6. SPACE AND WEIGHT

Blower operated systems have a larger foot-print on the plant floor; however, compressors often require a specialized room to contain the system. Modern blowers are significantly smaller than their predecessors and can be sized according to available space and necessary air supply volume and pressure.
A blower-operated air knife is larger and heavier than a compressed air version. However the system itself may be more compact when you consider the additional infrastructure required by a compressed air system.

7. NOISE CONSIDERATIONS

The level of noise on the plant floor is less with compressed air operated tools; however, the necessary compressors do produce noise elsewhere on the property. Noise from blower operated systems can be reduced significantly with the addition of an enclosure which also serves as additional protection for the blower. Depending on the ambient noise level of the plant, this factor may not be important.

SUMMARY

When deciding on an air delivery system for your application there are many factors to consider: the availability of electricity and compressed air, space and weight needs or restrictions, noise considerations, application particulars, and energy, system, maintenance, and operating costs. Production rates and output can be negatively affected by choosing the wrong system. Additionally, if ill-suited to the application, the system will cost far more to maintain and run. It is important to research all the available options before committing to buy.

No two applications are the same and what works for one may not work for you. STANMECH has experience with both compressor and blower operated air delivery systems and can help you make the right decision for your individual application. Where applicable, STANMECH may also be able to perform an ROI analysis on your system.