Extractor fans with Humidistats for homes

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To assist people in choosing or using extract fans that have a Humidistat I have produced this guide.
The notes are for Vectaire fans, but the principles apply to all fans with humidistats.
Background to humidistats
These work by sensing the ambient humidity and dependent on the setting that you make internally with the sensor (adjustable 0-100% approx) the fan will turn ON and OFF automatically. Don’t forget that to reduce sensitivity you turn it UP towards 100%- i.e. clockwise so that it is less sensitive!
It is very important to remember that the sensor INSIDE the fan has to sense the humidity in the air around itself. Sometimes the room is steamy but the air INSIDE the fan is NOT! The moment you turn on the fan the air inside becomes humid and the fan will run on until the humidity drops.
So, please remember that the fan will not always automatically come on itself if the humidity inside its housing is not high enough to trigger the sensor. (I find that two fans I have fitted at home do not come on until I turn on the fan, but always remain running on the humidity sensor after I turn them off. Once they came on themselves if I flapped a towel at them….quaint, but obviously this pushed some damp air into the casing & they started up!)
If you do adjust the humidistat DOWN anti-clockwise (BLUE trimmer) so that it comes on earlier (i.e. when the humidity is lower) please be aware that the fan may run 24 hours per day because the humidity sensor is set too low! The UK is quite a humid place…especially at night!!!!!!!! With my two home fans I got too clever by trying to get them to come on automatically and set the sensors too low… they never turned off! (I have had a few other customers experience this….. which they resolved by adjusting the stat upwards -clockwise).
How to adjust them
The most important thing before you adjust the humidistat is this….


If you just turn off the light switch the fan is still receiving power from the 2nd live! (That’s how it can run when the light is off!). If power is on, changes are ignored. It’s also safer with the power OFF!
Then, simply follow the instructions in the installation leaflet supplied with the fan. I suggest that any adjustment is VERY VERY small… then try it for a week or so…. If you turn it only as little as 5 degrees down the fan will probably run 24 hours per day the moment it rains outside. These are very sensitive. If you adjust too much and the fan runs constantly do the following:

1.       Turn off the power at the fusebox.
2.       Turn the timer adjuster anticlockwise to minimum setting (RED trimmer)
3.       Turn the humidistat adjuster clockwise to 100% (highest setting)[BLUE trimmer]
4.       Turn on the power and the fan switch
5.       Turn off the fan switch and let it run on the timer…(lowest setting is about 50-70 seconds). It should turn off after this.
6.       Turn off the Power again
7.       Adjust the humidistat anticlockwise to about 80-85%.
8.       Turn on the power repeat 4, 5 above.
9.       Leave it at this setting for a few days.
10.   Repeat 6-9 again at a VERY slightly lower setting.
The fan has a night time set back to stop running at night when the humidity is much higher but sometimes if you set the humidistat too low it will still run at night on its own. Re-adjust it upwards (clockwise).
My best suggestion is to never touch the humidistat at all. It should be set at 70% from the factory. That is ideal for UK. It should work perfectly after the fan is turned on and then will stay on until the room will be nice and dry. If you adjust it too low you may find it comes on automatically when you have a shower – but it may also run at night if it is very humid outside. If you find the humidistat needs extra time---why not use the timer – adjust it to stay on longer – say 15 minutes. It’s a top of the range versatile fan – enjoy its capabilities.
Hope this helps

See you on ebay! 

Updated January 2007

RED Trimmer = TIMER
Remember – Turn off the power completely before you adjust the fan settings..
otherwise it ignores your changes…………………

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