Acceptable Noise Level Of The Domestic Extractor

By Author: Henry Janice
Total Articles: 119
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If you are in the process of selecting and researching a domestic extractor fan, you will know that there are various technical aspects to consider, including number of air changes per hour, room size, extraction rate, part L of the building regulations, duct length, the bathroom zoning system and the resultant air pressure, energy usage, and IP rating. The list appears to be unlimited.

The decision to retrofit an extractor fan is generally propelled by the requirement to expel steam from cooking smells from a kitchen or bathroom smells and is made by the property owner. While installing a fan in a new building, an electrical contractor or a property company will install fans to meet Part L of the building regulations. In both cases, the single most vital factor is the air extraction rate and the amount of air removed over a given period. This is mentioned in meters cubed per hour or liters per second.

Nonetheless, a vital consideration which is frequently neglected by the homeowner and somehow neglected by the third party contractor is the noise generated by the fan while in operation.

Most manufacturers ...
... mention the noise level of their extractor fans in decibels dB in the technical specification. Such information is now conveniently found on the websites of the wholesalers, retailers and manufacturers. Those fans which don’t clearly show the dB possibly have something to hide and should be avoided.

So what is an acceptable noise leve? To some extent this is subjective, which is fine to some might be irritating to others. The fan type and the installation, nonetheless does have a huge impact on this answer. Most kitchen fans are 6 inch in length, which is to say they use a 6 inch impeller. Consequently, a bigger motor is necessary to drive it. There is just no way of avoiding the fact that a bigger motor will cause high decibel level. Obviously, even the quietest 6 inch fans are louder when in operation that the noisier four inch ones. Nonetheless, the kitchen is a room which can accommodate high decibel levels. Why? Well, think about how the fan is used. Almost definitely the fan is used to extract the cooking smells.

Four inch fans nonetheless are used at entirely different times. Night time visits to the toilet or bathroom, for instance, when the house is completely quiet are much more audible. The shutting and opening of a door, the creak of a floorboard all can be heard in different parts of the house. In this situation, fan noise becomes much more prominent. Until lately, this just can’t be avoided as motors were quite noisy. Nonetheless, almost all the manufacturers now make a quiet fan or range of silent fans. If the fan is installed properly, and not mounted on the wooden joist, they will be silent, just like a compressor noise, even in the middle of the night.