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W. Tombling Ltd. |
You are here:- home > cooling index > fan index > choosing a portable fan Choosing a portable fanThe most common question we are asked is ‘which portable fan should I buy?’. Below are the most important things you should consider when choosing a fan.EfficiencyThere are several factors that affect the efficiency of a fan:Case design – Fans housed inside casings are much more efficient than those enclosed in open wire guards. For the same diameter of fan the airflow can be upto 50% higher.Although efficient portable fans are more expensive to purchase initially, they are less costly to run than their cheaper inefficient counterparts. For a 10,000 m3/hr fan operating for 8 hours a day, 5 days a week, the extra cost is typically recouped in 4 to 6 weeks. When choosing a fan always compare energy consumption, which is measured in watts. To calculate the running cost of a fan for one hour, multiply its wattage by the cost of one unit of electricity. Fan and air noiseCareful design of the profile of the fan blades reduces noise levels considerably. Perhaps not a major consideration in a noisy factory, but definitely very important in an office, shop, restroom, etc.Noise is measured in dBA one meter from the fan, while running at full speed. When comparing fans always check the noise level, for an office or shop 60 dBA is considered to be acceptable. Impellor size and airflowMany people buy the biggest fan available assuming it will give the highest airflow, as noted above the design of the fan and casing have a big effect on the airflow of a fan. A large inefficient fan will certainly use the most energy, but not necessarily produce the highest airflow.When selecting a fan compare airflow not size. Airflow is measured in CFM (cubic feet per minute), m3/s (cubic meters per second) or m3/hr (cubic meters per hour). To convert: CFM x 0.000472 = m3/sec CFM x 1.7 = m3/hr Speed controlAs noted above inexpensive fans often have simple inefficient two speed controls. A portable fan with stepless electronic control will be more flexible because:The output can be set exactly at the level required for any situation.As a general rule, always choose the fan with the biggest airflow. If the airflow is too big the speed controller can easily reduce it, nothing can be done to increase the airflow of a fan that is too small. QualityThe most difficult aspect to evaluate, as there are no figures to compare. Quality includes things like the materials used in construction, their thickness etc. These will depend on the intended use of the fan, for example a fan designed for light domestic use is not as durable as one built for commercial use or heavy industrial use.Look for casings that can withstand knocks and being dropped. For long term reliability the fan motors should be maintenance free and sealed for life, cables should be scuff resistant and fitted with rubberised industrial quality plugs. Choose a fan that is designed for commercial or industrial use. Low cost domestic fans will not last very long in the typical office or factory. Activair portable fansActivair portable fans are designed for commercial and industrial use; they use high quality components, and are durable, efficient and quiet.Activair portable fans are available to suit most workplaces: The Rapid500 is a variable speed ventilation and cooling fan, that is suitable for use in shops, offices, industrial units, and on construction sites.Activair portable fans are manufactured in the UK to the highest standards. Unlike low cost Far East imports they are designed for to provide years of trouble free operation, and for complete piece of mind they all have a full two year parts and labour guarantee. You are here:- home > cooling index > fan index > choosing a portable fan
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