Dryfix News

Not a fan of poor ventilation

1st September 2018

We don’t specify or install these types of through the wall fans, why? Well, basically because we think their poor. Here’s an example why.

Stylish fans seem to be new bathroom gimmick, self opening and closing grills, interchangeable colour face plates and integrated lights anything to bump up the price. But does the elevated price really mean better performance? Not at all.

Here’s a typical 100mm through the wall bathroom fan. It’s quite a popular fan and retails at around £120.00. Stylish I suppose is subjective but never the less it looks sleek. Most people assume because they can hear it, it must be effective and generally the more noise the better it’s working right, well not really!

Here’s why I don’t like this particularly model: Firstly its only a 100mm through the wall fan.  As such, these tend to have quite a small motors which are sized to fit within the 100mm through the wall ducting. Inevitably these are never going to be as powerful as larger 150mm fan or an inline unit which are generally much bigger. Secondly, through the wall fans are almost always installed on an external wall or within the ceiling which may not always be the best location, just the most appropriate for their installation.

This particular model has a face plate which cleverly disguises the gubbings of the motor and axial blades, safe yes, although the faceplate hides dust and debris build up within the fan as such, home owners have no idea when the fan requires cleaning. The face plate as highlighted in this video also restricts the performance of the fan. With the use of a velocity manometer the video shows the performance of the fan with the face plate on at 13.5 l/s. When the face plate is removed however the performance of the fan increases to 16.5 l/s. Whilst it’s only an improvement of 3 l/s its enough.

If I were to compare this to an equivalent 100mm inline fan most inline fans will achieve between 25 – 30 l/s and cost similar in price

So, when given a choice I choose an inline fan mounted within the ceiling every time.

Just last week our team of technicians installed six new ceiling mounted fans replacing the existing cradle or through the wall versions to a series of grade 2 listed building in York.

Ventilation in our homes is important to prevent problems with condensation and mould, don’t be a fan of style over substance.




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