Bests & Worsts Reviews from Amazon

As an experimental scientist, I tend to be careful in selecting what gadgets and appliances to buy. Humidifiers seem like a low tech device that one might think they're more or less the same. They all put moisture into the air by simple mechanisms. How big a difference could there be? I didn't give much thought to it until I had to replace my old ones recently. Past experience had taught me to avoid ALL ultrasonic and warm mist models. The ultrasonic models are quiet, but they put white dust into the room. They work by launching microdroplets of water into the air as visible cool mist. The droplets evaporate quickly, but the dissolved minerals in each droplet are left in the air as one tiny particle of dust. They either end up in our lungs or settle all over the room. The severity of the problem depends on the level of trace impurities in the water. Some people resort to using distilled water to mitigate the problem, but that's costly. Besides, distilled water has impurities too, just less than tap water. This is a classic case of bad engineering design: solve one problem by creating another one. Warm mist models heat the water to make vapor and it runs up the electric bill like using a small air conditioner in the summer, because it's on 24/7 and the AC may be needed only for a few hours a day on some hot days. This is an example of wasting big money on a small problem. A leading consumer magazine recently also confirmed my long standing suspicion that these two types of designs launch bacteria or other micro organisms in the water into the air. The only design that gives clean air is the wick/evaporation variety. The wick filter draw water up from the base reservoir, traps the minerals and bacteria in the pores while the moisture is released into the flowing air forced by a fan. It costs money to replace them, but it's nothing like the cost of heating the water or gallons of distilled water everyday.. The biggest reason that makes people stay away from the wick models is the fan noise. I have never been happy with the ones that I have owned, just put them in locations where they're less audible, lived with that for cleaner air. When I looked for new ones this winter, I decided to go through the trouble to take a few home to deliberately check the fan noise and look at the design critically without putting any water in them. That way they could be returned as new. I ended up keeping two different Honeywell models: HEV320 (this model) and the bigger HCM-350. (So I didn't buy from Amazon.) This small HEV320 is the best. It looks deceptively basic, but it really got all the design elements right. At the low fan speed, it's as quiet as the ultrasonic, good enough for my master BR suite that is about 400 sq. ft. total. Running 24/7 at this speed, I only have to refill the 3 liter container once a day. (For smaller rooms that need less moisture, one could just use a timer if so desired.) It's small and light enough that I can easily hold it with one hand under the bathtub faucet, don't have to make a trip to the kitchen sink. The opening is large and so it's easy to clean. The container is shaped to give a good grip, easy to lift up and set down with one hand without dripping water around the base, a good sign that the valves and seals are made and fit well. The base tray has a clever design that holds very little water and not spill easily when carried to the sink to clean. Power consumption is merely 12W at low fan speed. Running it 24 hours would cost pennies a day in electricity, or between $1 and $2 a month. High fan speed will cost under $5/month, but it's really not necessary to run continuously on high. (It could be useful to run for a while when the unit first starts up in a dry room.) A warm mist Honeywell model would use about 10 times the power. You can imagine how quickly the electric bill would exceed the cost of the unit. Living in the snow belt may require running a few of them all winter continuously and the electric bill will explode. It didn't escape my attention that the path of air flow is well thought out. Fan blades are unusually short so that dry air enters in the bottom rim and flows upward out the top. The path is parallel to the cylindrical surface of the filter, giving it maximal time to take up vapor. As a result, despite the low fan speed, it puts more moisture into the air. This slow and even evaporation makes the filter last longer. Exactly how long will depend on the amount of impurities in the water. Water molecules are light and they jump into the air one by one. The haevy mineral molecules and bacteria are left behind In many designs, the air flow across the filter and so much of the evaporation occur in a small zone just above the water line. This could result in rapid and dense deposition of mineral in that zone and plug up the pores. Once that happens, no water could be drawn up by capillary flow and the top portion of the filter become bone dry. The filter is dead when it happens, but a good part of it still perfectly good. So the way to get the longest filter life is always to run the lowest fan speed and never let the filter dry up. Other ways to extend filter life include flipping them over frequently, soaking them in a bucket of water/vinegar, rinsing with fresh clean water, etc. Filters are no different from a kitchen towel...after soaking up some spill, it should always be rinsed right away and not let it sit around to dry. Common sense tells us that the filter should be frequently rinsed and never let it dry up and the minerals hardened. The filter is made of synthetic fiber. If rinsed gently everyday, it could last as long as one wishes. In practice, one should just check for color change and dryness when the tank is refilled, rinsed them as necessary. This is a matter of how clean the water supply is and if one is willing to spend a little time to not be wasteful, produce less garbage and save some money. What people often overlook is the cost of electricity because it is invisible if one doesn't look at the electric bill. I am so impressed by how Honeywell got all the design details right in this model that I bought another larger model they made (HCM-350 Honeywell Germ Free Cool Mist Humidifier, HCM-350) for my family room that's about 600 sq. ft. The design elements are very similar. Again, I only run it at the lowest speed and it's only slightly louder, still competitive with ultrasonic models. It has a larger footprint and a bigger container. Power consumption is just 16W at low fan speed, costs only a bit more in electricity. (Medium/high speeds use 28/54W). That's a small price to pay for higher moisture output. Console type models for the whole house are always bigger and louder, more power hungry. It's better to buy more of these quiet little ones. Running them at low speed is more energy efficient, less noisy, and the filters last longer. There are just two small flaws in the design of this model: (i) the water tank would not last a full day even at the lowest fan speed, (ii) the filter is actually smaller in this bigger unit. I have to refill the tank more than once a day and clean the filter more often. So scoring purely on "design", it loses out to the smaller model. Having two models of the same brand has another advantage. When ordering replacement filters, there are usually some savings on price and shipping by placing a larger order. That these Honeywell models carry a 3-year warranty is exceptional. They can do it because they're so simple that there are not many ways to fail. There are just a fan, a switch, a valve and a gasket seal, nothing complicated.