Frequently Asked Questions - Thermal Management

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We hope that you found all of the information that you require within our website but we're aware that some questions will always need to be answered. If you can't find the answer to your question below, please feel free to contact us on 01782 349430 or email us on [email protected]


Technical & Product Information Axair Online


How does a fan filter work?

A fan filter is used to dissipate heat within an enclosure or cabinet. Multiple units may be needed to fulfil the required airflow which can be located at differing points depending on enclosure space and design. For more information about the methods of enclosure cooling please visit our knowledge zone.

Fan filters are an all-in-one unit, composed of a fan, a plastic casing with a removable filter media. They ‘click-fit’ in square cut-outs on units where the plate thickness is no greater than 2.2mm. Where the plate thickness exceeds 2.2mm, screws can be used to easily install the fan filter unit. Please note that screws are not supplied but the type required will be included in with the unit. 

Can I buy a filter unit without a fan?

Yes, filter exhausts are available as seperate items. If an individual frame fan is required you can visit our sister website or contact our team on 01782 349430 as these are not available on Axaironline.

What bearings are used within your filter units?

Our fan filter units are manufactured using ball bearings. Ball bearings offer a higher life expectancy of the product, and operate at higher temperatures than sleeve bearings. For more information, visit our Knowledge Zone.

What is the difference between Standard and Reverse airflow?

Standard and reverse airflow relates to the direction of the flow of air through the fan filter. Standard airflow draws in air through the front of the filter unit into the enclosure or cabinet. Reverse airflow extracts air from the back of the filter outside the enclosure.

On what occasion would I use a roof fan?

Where a cabinet or enclosure does not have the space to include multiple filters on the side walls or air needs to be ejected through the top of the cabinet then a roof unit can be used. Roof fans use centrifugal fans which are designed to operate under higher pressure. These will handle dirty filters and highly density-packed enclosures.

What do your product codes mean?

Each product code can be broken down easily to enable you to identify the product type. Please refer to our Knowledge Zone for more information.

What does an adaptor do?

An adaptor can be used when there is limited space in the enclosure or cabinet, by using the adaptor more internal space is created as the fan filter unit is located more externally. The spacer can be fitted on the enclosure by the way of screws and the fan/filter can be fitted onto the spacer as normal, using the ‘click-fitting’ system.

What type of filter media is provided?

A G3 filter media is supplied with all fan filter units and on replacement media. This is a thicker composition which enables more effective filtering of dust and liquid ingress giving the fan filter units an IP rating of IP54. Some manufacturers use a lower grade G2 filter media giving the unit a lower level of dust retention and liquid ingress protection.

How many times can I wash the filter media before it needs replacing?

The media can be maintained by washing, blow drying and lightly beating. Dependent on the environment this can be done up to ten times before the media needs replacing.

What is the difference between a normally open and normally closed thermostat?

A Normally Closed (NC) red thermostat has closed contacts when the temperature is below the set value and opens with rising temperatures. A NC thermostat can be used alongside a heater or for switching alarm signal devices when the temperature drops below a certain value.

A Normally Open (NO) blue thermostat has open contacts when the temperature is below a set value and closes with rising temperatures. A NO thermostat can be used when using a fan to remove heat or for a temperature alarm when heat rises above a certain value.

How do heaters work and do I need one?

Heaters are used where damage from condensation must be prevented, or where the temperature must not fall below a minimum value. A drop in temperature can lead to a serious malfunction or to component failure. Convection heaters protect against low temperatures preventing the formation of condensation.

Heaters work using Self-regulating Positive Temperature Coefficient (PTC) thermistors. So as the temperature rises the resistance increases and less power is used. The reverse is true when the temperature drops.

What is a door switch and do I need one?

Door switches are used to switch the light on when opening the cabinet door, or power off the enclosure when the door opens. The same reference is used weather you require Normally-Open or Normally-Closed.

Are all the products listed ERP compliant?

All products listed on Axair Online are compliant to the ErP Directive.

I need a datasheet for my product, where can I download this?

All datasheets are listed below the specific product but can also be found in our downloads section.