UPDATE January 10, 2022 Because we live in the dry climate of the high desert in SW Colorado, I've become something of a connoisseur of humidifiers over the years, owning a number of different models of different brands, including this Honeywell tower model, which I have replaced with what I consider to be a much superior (and less expensive) product, the Honeywell warm-mist humidifier. We've owned three different models of the Honeywell warm-mist design (see photos), and Honeywell has been consistently improving each new generation. In this review, I'll call them Gen 1 (HWM340), Gen 2 (HMW440), and Gen 3 (HWM445). Trust me, I have no connection to Honeywell, but I'm pleased to find good products and to applaud efforts to improve them. All three generations share these basic features: (a) Top-fill: Just pour water into the top--no need to remove any part of the unit and take it to the sink or tub for a refill. The unit automatically turns off when it runs out of water. (To fill the unit's water reservoir, I use a 2-gallon gardening water can with the spray cap removed: the part with the little perforations in it.) (b) No expensive filter/wick to replace at regular intervals as with the tower model. (c) Water is heated to boiling by the "heat dome" and emerges from the unit in a fine mist that looks more like smoke than spray. Boiling hot water probably limits bacteria growth better than cold-water spray. (d) water from the reservoir is released to the heat dome area by a float mechanism. (Be sure to remove the packing tape from the float before first use. And be sure the removable float is firmly seated, or the unit may leak water from the side wall.) (e) THIS UNIT REQUIRES REGULAR CLEANING to prevent heavy scale buildup on the heat dome. Cleaning is pretty easy. Once a week, I place the unit in a sink and remove the "mist chimney," but leave the "heating element cover" (heat dome cover) in place, and pour vinegar into the heat dome area until the vinegar just covers the nearby float. Then I put the chimney back in place and let it all soak overnight. I want the heat dome cover and the bottom of the chimney to soak in the vinegar along with the heat dome to facilitate scale removal. The next day, I pull out the chimney and dome cover and clean off any scale. Scale is harder to remove from the heat dome itself, but with the weekly vinegar soak, I can usually scrape it off with my thumbnail. Sometimes I use a wooden chopstick to gently scour the base of the heat dome where scale and slime sometimes collect. Depending on the hardness and minerals in your water, you might need to clean the unit more or less often than once a week as I do. TIP: We use this unit to add moisture to the main living area of our house: living room, dining room, and kitchen, which have wood floors that can easily be damaged by water. I've yet to find a humidifier that didn't leak at some point (on this unit, my fault, because I didn't have the removable float seated properly.) So, I have taken to placing the humidifier in a plastic bin obtained from a farm/ranch store. As an added precaution, I place a moisture sensor in the bin. I'm a big fan of the battery-powered Zircon Leak Alert Water Leak Detector & Flood Sensor Alarm, which we have also placed in the cabinets below our kitchen and bathroom sinks, at the ice-maker water inlet behind the fridge, and at the water heater. It beeps in a SOS pattern that distinguishes it from our smoke alarms. These devices have thankfully alerted us to leaks in the middle of the night (and during the day) on several occasions. AN ASIDE: Our newest Gen 1 unit recently stopped working just short of the end of its 3-year warranty period--apparently a defective electrical switch. Honeywell is now operated by a conglomerate oddly named "Helen of Troy." The customer service number is prominently displayed on the front cover off the humidifier's operating manual--in marked contrast to other companies, who like to hide customer service numbers. When I called, I quickly spoke to a human being who immediately and graciously fulfilled the terms of the warranty, and a new Gen 3 unit arrived at our door within a few days. So now, I not only like the humidifier, I like Helen of Troy--"the face that launched a thousand ships" and probably even more humidifiers. For those persistent souls still with me, I'll point out a few of the design improvements I've seen in these units over the past several years. The Gen 2 and Gen 3 units have a squarish shape with a somewhat larger water capacity than the shorter, oval-shaped Gen 1 model. More capacity means less frequent refills. The 2 and 3s are rated at 1.5 gallons, which is pretty good for a portable humidifier, but I believe they hold closer to 2 gallons. In the Gen 2 and 3 models, the breathing slots (or whatever they are) at the side wall of the unit in the heat dome section are elevated much farther above the base than in the Gen 1 model. This is good because the newer models are less likely to leak water if, say, the float isn't properly seated and when carrying the unit to the sink for its weekly cleaning. (Be careful: the unit may still have boiling-hot water in the heat dome section.) The Gen 3 model has a wider top-fill opening to the water reservoir than the Gen 1 and 2 models, which reduces the possibility of splashing water outside the unit when filling. (Another good reason to place the unit in a waterproof bin to contain leaks and spills.) The Gen 1 and 2s have mechanical switches to turn the units on and off and select high or low operation. Gen 2 eliminated the dial, which could fine tune the desired humidity level. Gen 3 replaced the mechanical controls with touch controls and reintroduced the the fine-tuning option with five preset humidity levels designed to turn off the unit when the desired humidity level is reached. I miss the tactile response of the mechanical on/off switches, which may be easier to find and operate in a darkened room...but I would likely become accustomed to the touch controls after some use. THIS IS A KINDA BIG DEAL: For several years, we have been running two Gen 1 models side by side to reach 30% humidity in our contiguous main living area (living room, dining room, kitchen), which has high ceilings and in winter is heated mostly by a free-standing gas (propane) stove. The Gen 2 and 3 models seem to put out more moisture than Gen 1. We now seem to be reaching and maintaining 30% humidity or greater with only the single Gen 2 unit, and for the present we are storing the new Gen 3 unit until needed. We'll see how this arrangement works over the remainder of the winter. Happy humidity hunting.
