I've been using the Alen BreatheSmart Flex for about 2 years now and just purchased a second one. It's got a wide range of speeds and the lowest speed is so quiet, you hardly know it's on. The controls are super easy to understand. It's not an inexpensive item though (otherwise you'd get 5 stars), but if you can afford it, it's worth the improvement for someone like me with allergies.