Bests & Worsts Reviews from Amazon

First and foremost, I want everyone to understand that this is NOT an air conditioner or furnace, nor does it create colder or warmer air. All it does (and claims to do) is move a little more air out of a weak register. Another thing...do NOT expect this unit to be as quiet as your old register. Your old register didn't have 2 fans running...this register will. Anyone expecting to spend $35 and solve an entire room's HVAC problems has extremely unrealistic expectations. That said, this unit has worked decently for my HVAC needs. I live in a 3-level condo, where the bottom floor will normally have a 10-degree difference from the top. Unfortunately, the top floor happens to be the bedroom, the one room that temperature actually matters. Rather than do some extensive modifications to the house, I figured I'd give this unit a shot. It's a pretty cut and dry operation, with an on, off, auto-heat and auto-cool setting. The latter 3 settings all have low-medium-high fan settings. From the way some people were talking, I was expecting this thing to possibly sound like a box fan, though I was relieved to find it to be much quieter than that. It was, however, still noticeable when it was on. Airflow was maybe 50% better than without, although it didn't quite seem as powerful as I was hoping. I'm almost positive that these fans are almost interchangeable parts with a computer CPU fan. The Auto Heat/Cool functions are nice, but take a good amount of tweaking before you get them in the right place. Be prepared to have to make at least 3-4 adjustments, minimum. After doing some other research, I found that many people have come up with an answer to the semi-noisy fans, and I figured that I would try it myself. If you turn the register over and cut the air grates off the backside, it will make a drastic improvement on noise. (See attached picture) I would go as far as to say it's a 50-75% improvement of overall noise. People also claimed a 50% improvement on airflow, although I personally found it to be maybe 25% better, if that. I would, however, HIGHLY recommend this modification if your primary complaint about the register is how much noise it makes. One word of caution though...this modification will likely void your warranty, and you will NOT be able to return the item. Choose wisely. Lastly, I bought this as an open-box item and got it quite a bit less from Smarthome. When it showed up, I couldn't even tell it had been opened. It was probably from someone who didn't care for the noise and was a like-new return. If I were looking to pick up one of these, I would strongly consider an open box item. Summary: PROS: -Works fairly well (4-6 degree difference on 3rd floor home) -Quiet after modification -Good value given other expensive options -Auto Heat/Cool functions CONS: -Semi-noisy fans if left unmodded -Somewhat short cord -AC adaptor gets pretty warm -Auto Heat/Cool takes some tweaking Final Thoughts: I would definitely recommend this for around $30. If you pay $50, it's getting a little steep. If you're afraid to cut off the rear air grates, you may not care as much for this product, as it yields a drastic difference in the noise level.