The most important room of any household needing an extractor fan is undoubtedly its bathroom. It is essentially needed to keep away building up of mold, humidity and above all the odor. A small four inch fan keeps the bathroom healthier by throwing out stale air and odor. These days there is a very vast variety of bathroom fans. You get them with timers, PIRs or you may opt for low energy low voltage fans and may even have a slimline and inline fan. Here we give you detailed specifications and features of different types, enabling you to choose the most appropriate.
1. Wiring regulations and Bathroom Zones
2. Extractor Type
3. Size
4. Air Extraction Rate
5. Operation
6. Noise
7. Aesthetics
Before we start, I just wanted to share this cool video with you. It’s quite informative, but what I really like is how this guy explains it all with such enthusiasm.
1. Wiring regulations
As electricity and water make a deadly combination, strict regulations are in place, dividing the bathroom into 4 zones: 0, 1, 2, 3. Zone 0 is in the bath. Zone 1 goes up vertically to a height of 2.25m above the bath. Zone 2 covers all directions for 0.6m from zone1 and zone 3 extends laterally for 2.4m from zone 2.
It is crucial to install the right fan in the right zone. Bathroom fans can work on two voltages; Mains voltage (240v) and SELV or Safety Extra Low Voltage (12v). Bathroom extractor fans working on mains should only be used in Zone 3, whereas Zones 1 and 2 should only have SELV bathroom fans (12 volt), with the transformer being kept in Zone 3. The only exception to this rule is the Airflow QuietAir: a bathroom extractor fan working on mains specifically designed with an IP45 rating that may be used in all the three zones. The other special type of 240v bathroom extractor fans are known as inline fans. These are installed in the loft space above the bathroom in the middle of two lengths of ducting. As the motor, impellers and all electrical components are beyond the zonal area, with only the duct and grille in the bathroom ceiling, they too are found suitable for being used in zone 1 or 2 above the bath or shower.
Types of bathroom extractor fans
Principally there are two types of bathroom extractor fans: Axial and Centrifugal. Axial fans are those that one often sees on walls and ceilings. They typically have an air extraction rate of 85m3/hr to 95m3/hr for a 4 inch model. These are appropriate for standard installations wherein the fan needs to be ducted through the wall. Centrifugal fans are most often inline duct fans, though exceptions are there. These fans are frequently much more powerful than their counterparts axial fans and have air extraction rates varying from 110m3/hr to 220m3/hr for a4 inch model. Centrifugal fans are principally better suited for installations needing long duct lengths. For instance The Vent AxiaSolo Plus may be employed in duct runs of up to 50m!
3. Sizes of bathroom fans
Bathroom extractor fans for domestic applications are available in two sizes: 4 inch /100mm and 6 inch / 150mm. In most of the cases a 4 inch bathroom extractor fan suffices the purpose. However for bathrooms exceeding an area of three meter square, six inch fans need consideration. At times, extraordinary circumstances also necessitate such fans; example will be a bathroom with no natural ventilation or a north facing particularly cold bathroom.
4. Air Extraction Rate
The rate at which a fan extracts out air is its most important specification. It’s measured in terms of cubic meters of air extracted in one hour or in terms of liters of air extracted in a minute.
Going by the stipulations of The Building Regulations a bathroom extractor fan must extract at least 15L/s in a normal domestic bathroom. Any 4 inch bathroom extractor fan would exceed this specification, and the present standard is 85m3/hr. A bathroom extractor fan that extracts air at the rate of 90m3/hr or above is considered powerful.
5. Operation
Bathroom extractor fans come with a range of operational features that suit different applications. The simplest one being the on/off switch via the bathroom light switch or integral pull cord. Bathroom fans with inbuilt timers are ideal for bathrooms that get large build ups of steam leading to condensation problems, as the over run timer keeps the fan running for the needed duration after it has been switched off and is especially helpful if the fan has been wired into the lighting circuit. It’s ideal to have a bathroom fan with a PIR sensor that automatically operates the fan when somebody enters the bathroom. Another good option is that of fans with humidity sensors, which get switched on automatically if the relative humidity reaches predetermined level.
6. Noise
Usually an axial bathroom fan generates noise of the level of 35dB (A) to 45dB (A), while the more powerful centrifugal bathroom fans have a noise level varying from 40dB (A) to55dB (A). Though centrifugal fans are noisier, the fact that these are housed in the loft space should not be overlooked. That way they get noise- insulated to some extent and thus reduce the level of noise.
7. Aesthetics
As you are going to use and see this fan every time and anytime you enter the bathroom, due consideration needs to be given too its looks. And, its not so expensive an accessory. Homeowners are spending big amounts to have a beautiful impressive bathroom by including modern lighting and bathroom fixtures, prompting manufacturers to design cool good looking fans that would go along the décor of any bathroom. You may even find it difficult to get that traditional box like design with grills.
I think that’s all you should know about this subject. I should have more bathroom fan reviews in the future, but I think I covered this topic in a lot of detail. Until I get some inspiration…take care.