Our home is a fairly dusty environment (we vacuum regularly, honest!), and after only two months of use I noticed considerable build-up of dust on our TS-409 Pro NAS - and this despite the fact there is only a very moderate air-flow through the NAS due to the fan spinning at a low speed.
A problem with the TS-409 is the lack of adequate dust filtering on the air intake ie. the front door, but fortunately it is very easy to add a dust filter sheet to the interior of the front door, preventing most airborne dust from entering the unit.
Figure 1 - Dust on front of door
Figure 1 shows the front door of the NAS - it has become so dusty you can clearly see where I have wiped it!
Dust on the outside is not too bad, as long as it doesn't impede air flow. But it does look a little unsightly and messy...
What is more of a problem is the dust that does get inside, because some of the dust that is drawn into the unit settles or gets caught on interior components - which is very bad if they run hot during normal use, because the dust acts as a thermal insulator over time, with the risk of component failure at some point in the future due to overheating.
If you've ever taken the side off your PC and noticed how everything inside is coated in dust, you'll know exactly what I mean!
Figure 2 - Dust inside the unit
Note the dust on the disk trays in figure 2, the white splotches on the tray handles. Compare them to the top tray (HDD 1) where I have wiped the dust with my finger. And remember, this is after only two months of use - another year would have turned into a horror story! Unfortunately there will already be dust like this deeper inside the NAS, but luckily at this stage it's not too serious to worry about.
If you open the front door of your 409 you will notice there is a recess inside the front door. The handles of the disk trays protrude into this space when the door is closed, however there is still some space between the two, which you will notice if you gently push on the centre of the door when closed - there is a little "give".
This scenario is perfect for adding a dust filter.
What is needed is a sheet of filter material cut down to size - 156 mm x 137 mm. You should be able to purchase these at any vacuum cleaner specialist. I bought a pack at
Godfreys at our local shopping centre here in Australia for the princely sum of AU$9.99. You may also need a tube of silicon adhesive to secure the filter at the corners, although I did not find this necessary. Silicon is a good choice because it allows easy removal when cleaning or replacing the filter in the future.
Figure 3 - Bag of filters from Godfreys
These are the filters I bought. The pack contains 3 filter sheets, one each of the type shown on the packaging in figure 3 above. The microfilter is very dense but thin enough to use. I felt it a little
too dense to allow sufficient airflow by the fan in the TS-409s. Another filter is too thick to use, but the third is just perfect. Just like the Three Little Bears.
It is possible to remove the front door of the NAS, but not really necessary in order to fit the filter. You can naturally fit the filter with the door attached but it does make the job a little easier when removed. The door hinges consist of two plastic pins and
it is very easy to snap these off! Do not think of removing the door unless you are confident in doing so. As I stated, you don't really need to remove the door.
Measure a rectangle (156 mm x 137 mm) on the filter sheet and cut the piece out. I suggest using a sharp knife and metal ruler on a cutting mat, as scissors will not give you a straight cut. Well, at least, not for me...
If you are steady enough with your hands, by all means use scissors. There will be enough of the filter sheet left over to cut a second piece if you ever need it.
Fit the piece to the door. You may wish to cut out a notch where the moulded latch protrudes from the door. I used small angle cutters to do this. You may also wish to place a tiny drop of silicon adhesive at each corner to secure the filter if it's a loose fit, but I found the disk trays will hold the filter in place against the door anyway. But without adhesive it's possible the corners may peel back over time though.
Figure 4 - Dust filter in place
And that is all there is to it! Refit the door if you removed it and it should close without any problem.
Figure 5 - All finished!
The filter will now greatly reduce the level of dust entering your NAS, thereby potentially prolonging its life.
Don't forget to periodically check the filter and clean it when there is a noticeable build-up of dust. You could just use a vacuum cleaner sucking from the front or if you wish to be more thorough, remove and wash the filter.
*UPDATE*
After 3½ months I removed the filter for inspection and cleaning. I've pinned it to the side door to clearly show the filter's effect - you can see what a difference the filter has made. All that fine dust, prevalent in the air, has been trapped in the filter and not within the innards of the NAS!
Figure 6 - Trapped dust in the filter after 3½ Months
I have cleaned the filter using the vacuum cleaner at half power, and it looks like I will have to do this every 2-3 months. How often it will need cleaning of course depend on how much dust is prevalent in the air, but certainly well worth checking regularly.