Purchasing fans can be a breeze

Sourcing fans is sometimes perceived as confusing. Here, G English outlines some common dos and don’ts regarding fan and supplier selection, both of which will benefit from open communication.

In the majority of cases, the best fan specification will be found somewhere between the desires of the engineer and the needs of the purchaser. Engineering will focus mainly on efficiency, performance and reliability, whereas the interests of the purchaser will probably centre on more commercial factors.

Fan selection
From a purchasing perspective, the most common frame sizes of 40, 60, 80 and 120mm will attract the most cost-effective pricing. Unit price may be higher for larger fans due to greater material costs, while the increase in manufacturing complexity for smaller fans typically has the same effect. It is worth noting however, that selecting the largest possible fan operating at a lower speed will deliver the optimum noise for a given airflow, as well as extending the life expectancy of the fan, thereby reducing potential future replacement costs. Careful thought should also be given to the fan width to avoid selecting a dimension that is uncommon or unique to any one supplier.

Bearing selection is another area that requires careful consideration, ensuring that the right technology is chosen to meet a given product specification. A sleeve bearing is likely to attract the lowest unit cost but should be avoided in applications where the fan will be subject to elevated temperatures, dust or moisture. There are also limitations on mounting orientation.

A ball bearing will command a higher unit price but should be considerably more durable for challenging applications. Furthermore, the expected life of a ball bearing fan should far exceed that of a sleeve bearing, so in applications where reliability or long periods of operation are critical, a premium front end is likely to deliver the best return on investment for both the end user and the manufacturer’s reputation.

Alternative bearing types, such as Sunon’s patented MagLev technology, can often provide a compromise that delivers similar benefits to that of the ball bearing in terms of lifetime and flexibility, but at a cost closer to that of a sleeve. To help purchasers make the right choice, a specialist distributor, such as G English, will seek to understand the specification of the end-product and the environment in which it is operating in order to make recommendations on fan selection.

Vendor choice
In many circumstances, internet search engines have become the first port of call when working on a project at concept stage. On-line catalogue distributors are often able to offer fast turnaround on a range of fans, enabling design engineers to identify a solution and make choices early on. Working with a product specialist, however, can help to navigate around the kind of headaches commonly experienced by purchasers, such as long lead times and end of life warnings. Selecting a solution with longevity of supply can significantly limit the risk of needing to allocate additional engineering resource for further testing and re-approval at a later date.

Although stock availability and fast delivery turnaround can prove invaluable for unforeseen or low volume requirements, sourcing from an on-line distributor will typically carry a price premium. A pro-active specialist distributor on the other hand should seek to understand a customer’s part requirements and build plan before considering all available options. Volume price breaks and stocking agreements are useful tools when striking a balance between price, availability and commitment.

Customisation is another aspect where enlisting a specialist distributor will pay dividends. Most fans are customised in some way before use by, for example, adjusting the lead length or adding a connector. Close communication with a specialist distributor enables any customisations to be incorporated during the manufacturing process, which will result not only in lower costs, but will also avoid any damage to the fans through mishandling during secondary processes.

Looking ahead, the potential benefits of sourcing through a specialist distributor are only set to increase. The latest figures from the Office for National Statistics suggest that UK manufacturing sector performance is at its best for nearly a decade. This, coupled with forecasted growth in global demand, could put considerable strain on supply and subsequently impact component lead times. Selecting a specialist distributor with strong manufacturer links could improve the likelihood of ensuring uninterrupted supply and optimum pricing, says G English, providing purchasers with the trusted advice and inside expertise required to help them navigate these challenges.