EC 90X25mm 70-270V

Added a fan to help cool down the area behind my refrigerator. Comes with an off switch and installed easy

Exactly what I wanted

Good

This review is for the Wathai 120mm x 38mm EC fan. I purchased two of these to replace two old shaded pole fans (non-muffin style) rated at 22 watts each that I had mounted to the top rear of my wood stove. Using a Ponie PN1500 energy monitor, I identified the combined power consumption of the old, high speed, whining fans was 38 watts. I started looking for more efficient fans since they often run for days on end. Researching regular AC muffin fans showed they weren't any better for lower power consumption. Turns out the typical, inexpensive, AC muffin fans are also a shaded pole motor design. I considered going with Brush Less DC (BLDC) fans but then I'd need a Switch Mode Power Supply (SMPS) to convert the AC to appropriate DC voltage for them. I also learned that using 48vdc BLDC fans with a SMPS would have been the more efficient route. However, that effort lead me to the newer EC designed fans. These are essentially a 48Vdc (or maybe 60Vdc) BLDC muffin fan with a SMPS built-in that works directly off-line (no AC transformer) to convert the AC to DC. By using PWM, the EC fan can handle a very wide range of AC input voltages (by design they should also be able to handle DC input voltages of same range, just like many SMPS can; but I didn't find any manufacturer's stating that).I tested the new Wathai fans individually in open air flow with the Ponie. The first fan measured 3.74 watts at 121.3Vac and 0.05 amps (power factor of 0.60) while the second fan measured 4.17 watts at 121.4Vac and 0.06 amps (same 0.60 pf). This is a big improvement over the same size and air flow rated AC muffin fans that use around 20-30 watts each. Based on these numbers the two new Wathai fans should pay for themselves in reduce electric consumption in just one heating season. Interestingly, with the two fans wired in parallel for my application, the Ponie showed the wattage fluctuating 0.05-0.1 watt. The wattage readings were very stable when testing one fan at a time.Overall the quality of construction is very good. The supplied mounting bolts are long enough to go thru an 1/8” thick mounting surface, the supplied grill, and both sides of the fan. The fan frame is a plastic material rather than aluminum; but I didn't find any of the lower priced EC fans with aluminum frames. The 48” long power cord (if count the plug prong length it would be 49”) appears to be of good quality; but is constructed with only 20-22 gauge wires. If you don't use the cord with the fan I'd recommend throwing it away. The small wiring makes the cord suitable for only 30-40 watts max. The grill is nicely made and as shown is a shiny aluminum/chrome color (I'd rather had black grills; but didn't find that as an option). The included connector clip does the job; but I went ahead and soldered/shrink sleeved with the power cord from the old fans for my application.I found a few negatives with the Wathai fan. I could not find any UL, CE or other international approvals for the fan or power cord. There's also no IP rating. There's no supplied locking washers. Most of the EC fans such as the Wathai are only single speed at this time. I could locate other brands with PWM/0-10Vdc variable speed control; but they were 2-4x the price. The power cord supplied with the fan doesn't have the wire ends stripped ready for installation in the clip so you'll have to do that when you get the fan. There aren't any instructions or a data sheet with the fan although it should be simple enough for most folks to setup/install. The label on the fan has no model/serial number (or a current rating like most muffin fans) so I'm guessing Wathai only offers this one model in this particular size. Finally, as another reviewer commented, there is RFI from the fan. My portable AM radio had an obvious buzzing noise over most of the AM band when I got it within one meter of the Wathai fan. My TV located about 3 meters away showed no problems with the fans and it is on the same electrical circuit. So pay attention to your application; this fan may not be the right choice for you.On the positive side. The fan moves air similar to the 100 cfm DC fan I compared the airflow with and the Wathai fan is reasonably quiet. I'm fairly confident it's meeting the db noise level cited in the ad. Plus the price is so comparable to the old style, inefficient, AC muffin fans it's worth buying as it will save you enough in electricity consumption that it could pay for itself in no time.Overall I'm very satisfied with the Wathai 120x38mm EC fan purchase. So far I've only used them a week; but if lasts as long as the 60,000+ hrs rating on the bearings I'll easily get my monies worth.

Worked as expected on 120 V during a very brief test. Well packaged too, with auxiliary hardware included.

I needed a small fan for a hot box I built to dry projects I worked on. This fit the bill and is able to provide proper level of air circulation without undo cooling affect.The noise level is just enough to remind me to turn it off when I am done using it. Installation was easy and build quality is good. Not worried about looks, I use it in a small shop.

I needed a replacement fan for our counter-top water cooler in our kitchen. This is the exact same size and just a little higher FPM than the original, so our unit is now even more efficient. It is a tad louder, but we had become accustomed to the noise of the old dying fan. Hopefully this fan will work as long as the original which was 12 years!

You have to assemble the fan by adding the screens to the side of the fan with 4 bolts and connect the wires. The product should come assembled and ready to use