You are in luck today. This is a direct comparison review between the three most popular currently available twin window fans: Bionaire BW2300 Twin Window Fan with Remote Control Holmes HAWF2043 Twin Window Fan Honeywell HW-628 Enviracaire Twin Window Fan If you are interested in purchasing any of those window fans, read on... I didn't intend to have to do this review because I didn't intend to purchase more than one of these fans. I can tell you now that all of these fans are super cheaply designed and built and none of these fans are perfect, but in my opinion, one is worse than the others. Holmes HAWF2043 Twin Window Fan : my rating - 3 of 5 stars I first purchased the Holmes HAWF2043 unit. It was lightweight and fit the window nicely although I had trouble with the extender which is located on the right side. The locks for the extender are located on the right side along the top and bottom edge of the fan, which is supremely stupid because as soon as you place the fan in your window frame and put weight on it, the bottom lock locks and you can not move the extender. What rocket scientist thought of this? So you have to unlock the locks before you place the unit in the window AND keep weight off the bottom lock until you have the extender adjusted to where you want it. This maneuver is not so easy, especially at first. Plus, the lock mechanisms can be difficult to move. At the time, I could not imagine anything worse, but I was wrong as I found out with the extenders on the Honeywell unit which I will go into in the next paragraph. This Holmes unit has the best placement of the power cord which is in the lower left corner... the location is high enough as not to interfere with the bottom of the window frame. This unit has two speeds, high and low. The controls are easy to operate. In fact, there is only one button and two switches. The button cycles through the high and low manual speed settings and then though the automatic temperature presets which are at 60, 65, 70, 75 & 80 degrees fahrenheit. If you set it at one of the temperature presets, the unit will turn off once the sensor reaches that temperature. It seemed to work although I did not have the opportunity to see how accurate that function is. The two switches set the direction of the fans to either intake or exhaust which can be done on each fan independently, so you could have one fan on intake and the other on exhaust for quickly exchanging room air with fresh air. This unit has 8.5 inch fans and they are relatively quiet at both speeds - naturally high is louder than low, but don't expect silence. I own a Kill-A-Watt P3 energy meter and this unit used 46 watts on low and 63 watts on high. I would have been happy with this unit except that two days into using it, the right fan started working intermittently. Of course, that is unacceptable. Returning. I give this fan 3 out of 5 stars because I feel that if you get a good one you'll be happy with it, but don't expect anything great. FYI: Holmes is a division of Sunbeam. Honeywell HW-628 Enviracaire Twin Window Fan : my rating 2 of 5 stars So with the right fan not working correctly on the Homes, I ordered the Honeywell HW-628. As soon as I saw it, I knew that I was not going to be happy with it. For one thing, the unit has 7 inch fans compared with 8.5 inch on the Holmes. So in order to move as much air, the fans would have to run much faster and the unit will be much louder. Time to install... I previously mentioned that the extenders on the Holmes were poorly designed, but the extenders on this Honeywell were MUCH worse. First of all, this unit has two shorter extenders on both the right and left sides instead of one longer extender like the Holmes has. Second, the four extender locks are, get this, located on the BACK of the unit, the side facing out the window! How are you supposed to set those? It was impossible for me. I ended up jamming the extenders into the window frame in order to keep them extended. Okay, so I finally get the unit in the window and turned it on. I found out immediately that my thoughts about the smaller fans, higher fan speed and noise were true. This thing is LOUD. Super loud. And buzzy. In fact, I'd go as far as to say that it is downright unruly. There is no chance you would use this in a bedroom even on low speed. The controls were easy to use although not completely intuitive. There are three speeds available on each fan - low, high and super high. You have to set each fan separately, which I think is stupid. I cannot imagine a scenario where I would want one fan on high and another fan on low, etc. The temperature setting dial is also extremely stupid. There are no temperature markings. According to the manual, you are supposed to keep the unit on until the room reaches a temperature that you like and then turn the dial back until the unit cycles off. Seriously? Each fan has its own direction switch for either intake or exhaust. The power cord is located on the bottom center of the front of the unit and its mounted too low so that it interferes with the bottom of my window frame. Who is designing these things? The one feature it had that I liked was that the grilles were directional and could be rotated to direct air in a 360 degree arc. On the power consumption front, this unit used twice the power as the Holmes! - 97 watts on low, 109 watts on high and 120 watts on super high. My unit was defective in that the switches for the right fan are wired incorrectly such that low is high and high is low, but super high is still super high... odd. Returning. Due to the noise level, I would not recommend this unit. I cannot understand how it has 4 of 5 stars and as of today, 262 reviews. Incomprehensible. Bionaire BW2300 Twin Window Fan with Remote Control : my rating 4 of 5 stars So after the poor experience with the Honeywell (They put their name on that piece of junk? They are a defense contractor!), I purchased the Bionaire BW2300 hoping for better luck. The first thing I noticed was the similarity between this unit and the Holmes. That is because they are both made by the same company. Bionaire, like Holmes, is Sunbeam. It has the same right side extender locks as the Holmes, but after the experience with the unusable rear locks on the Honeywell, I was happy to see them! One unwelcome difference is that the power cord is located on the bottom center of the front like it is on the Honeywell, which itself is not a problem but its also too low like it is on the Honeywell. I mounted the unit in window fairly quickly and turned it on. Its got three speeds, low, medium and high. It uses 8.5 inch fans like the Holmes and it is relatively quiet, although I think it may be ever so slightly louder than the Holmes on high. The controls are all electronic and it has an electronic temperature readout and thermostat. It is very easy to use. Simply choose a fan speed and put the unit into intake, exhaust or one fan on intake and the other on exhaust (air exchange mode). You can use it either in manual mode where there is no temperature control or you can set a temperature for the unit to reach and then turn off (automatic mode). This is easy to do using the simple up and down buttons to the right of the large temperature readout or you can use the remote control. Once you set it, it will remember your settings if you turn it off as long as you don't unplug it. The remote control works well and it allows you to control all of the fan's features and functions remotely: on/off, fan speed, air direction, temperature and to toggle between automatic and manual mode. Finally, there is a button to change the brightness of the temperature readout, although you cannot completely turn it off. The power usage was similar to the Holmes. The Kill-A-Watt read 43 watts on low, 49 watts on medium and 64 watts on high. Unlike the most popular review for this unit, my temperature probe was located in its proper track and it