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What is a plenum and UFAD?

The wonderful world of raised access flooring can be much more complicated than placing squares on steel pedestals! One word you may have heard is the requirement for the raised floor to become a ‘plenum’. The creation of a plenum is simply a fancy word for air sealing and reduction of air leakage from the floor void.

To create a plenum a gasket is manually applied to the raised floor panel post manufacture, the panel is then installed as per manufacturers guidance often around an underfloor air system. To confirm there is a reduction in air leakage a post installation test can be conducted by an independent test house.

There are a number of reasons why architects and specifiers are opting for the removal of the typical ceiling services and looking to floor based Under floor air distribution (UFAD). These include;

Reduction in material costs

Using a raised access floor with a minimum 200mm void eliminates the need for a ceiling based ventilation zone- typically twice the depth which helps to maximise floor to ceiling heights.

By opting for a floor based system the building height is reduced sometimes by up to 10% meaning the material and labour costs of the overall project are reduced. Also a reduced build height and construction programme means the building can be let and earning a return for the landowner earlier than ‘traditional build’ types.

Modern design trends

The overall theme of new office fit out has leaned towards increased ceiling heights and the design trend of exposed ducting. As pictured below at the fit out RMF completed at Dashwood House the exposed black ducting gives a modern and open feel ready for incoming tenants to personalise the space to suit their requirements.

Sustainability and air quality

A recent study by Waterman discovered that ‘The supply of air at floor level provides 20 per cent better ventilation in comparison to a ceiling-based HVAC system. The naturally rising air moves suspended particles upwards and away from occupants, resulting in a superior indoor air quality.’ It is also noted that ‘The floor by floor solution allows you to manage staggered leasing with minimal disruption, because each floor can easily be adapted to suit tenants as they come and go, or when their requirements change. This reduces lifecycle embodied carbon too!”

At RMF we can offer a number of solutions with both our new RMF PSA panels and our RMF Eco Range to work with the requirement for UFAD systems and the requirement for a plenum. If you have any questions call the experts on 01926 425289.


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