I'm on a roll and it's the weekend, so why not do another review, this time of the Duratool D03288 Fume Absorber and Fan, currently listed at AU$68.97 inc GST for the UK plug version as delivered. This was the specific model that I received in lieu of the Multicomp Pro unit that was originally in the tool bundle as that one is 120V-only and I live in a 230V country, so the folks at element14 were nice enough to let me choose a more suitable unit in the same price bracket. Incidentally, those models seem to now have gone to a Cool Tools RoadTest that is still open for enrollment.
It's a sad fact that many hobbyists working from home are likely to be soldering at their bench without anything in the way of fume extraction or absorption system. As a result, the vaporised fluxes in solder which are released may cause irritation to the eyes and nose, while leaving a distinct smell in the room that not all people would appreciate. Over time, this can lead to negative health effects. Proper fume extraction systems can cost upwards of US$1000, which offer high quality filtration and strong suction through a ducted pipe system. This may be suitable for professional applications, but home users often require something a little more affordable.
This is where the "low end" fume absorber and fan systems come into play, available from numerous outlets, they have an activated charcoal filter media through which air is drawn by a high-velocity AC fan, often similar in appearance to computer fans. This simple device offers some relief, as the media traps some of the fumes as they are sucked through by the action of the fan. While imperfect, it is definitely better than nothing and can be had at affordable prices - in fact, I just found that the EU plug version model (DT000473) can be had for just AU$49.56 inc GST. At that price, I would think that hobbyists should seriously consider having one on their desk as a form of "cheap insurance".
The unit itself was not transported carefully, and as a result, the box it was in had been partly damaged during shipment. The box appears to be a generic product which claims to be both a solder smoke absorber or a bench fan - a pretty neat trick! This unit can be hung or put onto a desk with adjustable angle and variable speed. It claims a 23W power consumption, with a sticker adhered to the box to rebrand the product as a Duratool product. Apparently, it is "100% High Quality", according to what it says on the box, but I'll be the judge of that.
The box features an insert with a slot which is designed to keep the fan in place during shipment. This was not sufficient to keep the unit in place when it comes to expedited shipping. The unit itself is wrapped in a foam-bag for protection during shipment.
Inside the box, we have the fully assembled unit including its stand, a double-sided one page leaflet and a spare activated carbon filter pad, with one already pre-installed in the unit. The power cable is captive to the unit, exiting from the side.
The design of the unit is such that the filters can be removed by sliding them out from the underside. This arrangement does hold the filters rather tightly, so removal needs to be done with care, otherwise the filter may come apart rendering it "stuck" inside the slot. It's not the best design, but it is very simple to manufacture. The appliance label is on the side which should be facing the soldering work, which is also slightly counter-intuitive, as most appliance labels are on the rear of the device, out of sight. The design of this unit has no "hood" or anything which might concentrate the suction of the fan and direct it to the working area, so keeping the fan literally next to the workpiece is advisable, otherwise the fumes may escape into the room.
The unit itself has a QC label affixed near the power cord entry. The stand itself is made of a moderately thin metal wire with rubberised sections. This clips into the side pieces where there are several detents to keep the unit at one of nine angles. This offers a moderate amount of flexibility in positioning of the head - better than fixed units, but perhaps not as good as screw-set units which can be placed at any angle. Unfortunately, the stand was not "100% high quality", having a noticeable asymmetry and lean to one side, interfering with the positioning of the unit at certain angles. Bending the stand into shape helped improve the situation, but the stand did have a slight tendency to rock. This did not cause any audible acoustic noise in operation, which is good.
The unit has two simple controls on the top - a dial for speed which is continuously variable, and a power switch that turns the unit on and off. It's nice to see that the cable is terminated in a proper Qiaopu branded power plug, with a proper Bussman 3A fuse as required. Being in Australia, I used a plug adapter, but in the future, I could just rewire the unit with a local plug instead. I wonder how durable the speed control circuitry is in the long-run.
Does it work? Well, yes, it does! Which is no surprise at all, since it's quite a simple device in concept. The carbon filter does a decent job of eliminating some of the soldering fumes - to illustrate this, I've used the smoke from a blown-out candle. The unit definitely has a noticeable hum in operation, but is not too loud even at the high setting and is not particularly distracting. Fume absorption works best in the high setting - I found reducing the speed had too much of an impact on how far it could pull in the fumes from, so I'd recommend users keep it on the maximum. However, if you do remove the filter, you could use this as an ordinary fan as well, which works pretty well. Perhaps this would be the geekiest desk-fan or bed-side fan for the enthusiast - after all, having a speed control knob is not something you find on many such fans! So while the unit has a rather simple design and flimsy stand, it seems to do the job just fine and won't break the bank either.
I think we can all guess as to exactly what is inside the unit - but I had to open it up anyway just to find out for sure. Oh hey, that's the screwdriver from my last post! Its tip only just reaches the recessed screws in this case ... lucky for me I'm not going to have to look for another screwdriver!
To fully open the unit requires taking off the knob and speed indication labels before the two halves of the case will separate. As expected, the power switch and a speed controller PCB reside at the top of the casing.
The speed controller seems to be a very simple single-sided PCB design with a single triac and some common-mode suppression to avoid interference.
As it turns out, the Earth pin is necessary on the plug, and it is internally attached to the frame of the fan, which is made of metal. It is unlikely the user would ever contact it, however, as it is encased by plastic all the way around, but better safe than sorry.
As for the fan itself, it is a very anonymous unit with no branding, and just the 220-240V AC specification listed on the front along with the CE mark. Will this be reliable in the long term? I don't know for sure.
At my workplace, we do have a proper ducted fume extraction system which is absolutely awesome. Of course, such low-end filter-fan systems aren't anywhere near as strong or effective, but how does it compare to other filter-fan systems? I've used a Hakko which is an expensive implementation of the same idea (AU$221.94 inc GST). This particular unit has a similar amount of noise and performance, but the biggest annoyance with the unit is that it is fixed in height and angle, thus it sometimes needs to come even closer to the item being worked on to effectively remove the fumes. The Multicomp MP740146 has some visual similarities with the design, so I'd expect this to be a common downside.
During my PhD, however, we didn't have the budget for a Hakko , so instead we opted for a cheaper alternative from a local electronics supplier.
This unit was more expensive than the unit being reviewed, listed at AU$74.95 inc GST, however has a more sturdy stand that is open at the front, making it easier to get it closer to the workpiece. It looks visually identical to the Duratool D00374 which is available from Farnell in the UK for GBP 30.26. The intake is covered with a hood, while the outlet has a fixed louver directing airflow up, so the rear can sit much closer to a wall and still be effective. This unit also has a wire-cage retention mechanism for the filter, making it easier to replace the filter.
A downside is that it only has a power switch and no speed adjustment. This is sufficient for basic use and acoustically, both units sound similar in terms of their noise. The pivot adjustment is done via screws, thus this unit can sit at any angle.
Taking it apart, it turns out the two units are probably more closely-related than I thought - the fan appears to have the same labelling that lacks any identification of manufacturer, although this fan only claims to be rated for 220V AC despite the unit being sold to me as being for 240V AC. So in terms of preference, I'd have to say both the review unit and this unit have their own merits and drawbacks, but I'd be happy with either one honestly.
To gauge their power consumption, I decided to test them with the Tektronix PA1000 Power Analyser, using power from a true-sine-wave inverter fed through a Variac to adjust the voltage to 230V +/- 1V at 50Hz +/- 0.5Hz.
The measured power consumption was as follows:
At Maximum - 18.952W
At Minimum - 7.925W
For comparison, the other fume absorber fan I own measured 20.958W under the same conditions. It seems that the speed control circuitry may be impeding the fan's full potential, or perhaps the fan itself is less powerful than the 23W claimed. I decided to further test the unit at 260V (maximum Variac output), and the power consumption reached 26.290W maximum and 11.290W minimum. At the minimum transient line voltage of 196V, the power fell to 12.836W maximum and 4.445W minimum. As a result, it seems the performance is highly dependent on voltage, which is an expected outcome for motor-driven devices, and perhaps the 23W is only achieved for 240V (maximum rated voltage) input.
While proper fume extraction/filtration systems are expensive, fume absorber fans are increasingly inexpensive and might be good insurance to have for any electronics hobbyist doing soldering at home. This Duratool D03288 Fume Absorber and Fan seems to be a fairly low-cost, no-frills product with a simplified design that does the job quite acceptably. Surprisingly, it even offers a fan speed control, even though the fan operates with a non-distracting consistent hum. The downside is that the filter changes are a little more fiddly, the angling of the unit is limited to nine angles, the stand might not be properly shaped and there is no hood to concentrate the intake. However, compared to other designs on the market, the product does have quite a few strengths over some of its competitors which are completely fixed in orientation. Testing seemed to show that the motor was perhaps not 23W at the "harmonised" 230V voltage, but perhaps a maximum figure at 240V.
But best of all, when you're not soldering, you could even be super-geeky and use it as a bench/desktop/bed-side fan! Seeing as I do have another fume absorber fan ... perhaps this second one will help me sleep better during those hot summer nights.