Aprilaire 400 Humidifier, 24V Drainless Whole House Humidifier w/Auto Digital Control .7 Gallons/hr

Let me start off by saying I installed this myself, and I am a technician by profession, so it may have been easier for me than for some people. It did not seem very complicated to me though, and the directions included appear very clear and straightforward. I think anyone with some basic tools and mechanically inclined could do this themselves, otherwise you might want to hire a professional installer. The kit included everything I needed except sheet metal screws and tubing (1/4" copper for water supply, 1/2 clear vinyl for drain), and some additional 14-20 AWG wire nuts. I also bought an additional T-fitting with 1/4 turn shut off valve to hook up the water supply in my 1/2" copper hot water pipe. I don't recommend using the saddle valve they provide in the kit for the piping, as they frequently fail, and do not meet code. I mounted the unit on the return manifold, and used a couple of 90° 6" elbows and a few feet of flexible HVAC hose for the bypass duct, and sealed it all with the silver foil HVAC tape. As for the functionality of the unit, it's working great so far. I really like the water saving feature on it. It comes with a composite material filter (paper/metal screen) and a tray with float sensors to shut off the water valve if it gets full. This makes for a much more economical use of water in my opinion, and still has an overflow drain tube in case of malfunction. I like the outdoor temperature sensor to use the automatic feature for humidity adjustment, and it also has a feature to turn on the furnace blower to circulate and humidify the air if the humidity level is too low, separate from the thermostat control, which is very nice. Both features work perfectly so far, and my relative humidity went up 10% after the first day. This is the most precise and full control featured humidifier I saw at this price point, and was a very good value for the money.

The AprilAire 400 installed on a Heil HVAC system with forced air / AC Full disclosure: I'm not an HVAC installer, plumber, or electrician (I'm not even a mechanic) and have never attempted any similar project prior to this one. I was not given this product in exchange for a review. I understand that does happen. Please read the entire text and especially the NOTES AT THE BOTTOM. Once I fully researched the installation procedure by watching a number of YouTube videos and perusing the manufacturer's owner's manual and installation booklet for the Model 60 controller and the main unit, I decided I would order this humidifier to replace another, different brand, unit that was not working. WARNING: Ensure the power is OFF for the HVAC circuit prior to attempting the installation. Allow yourself ample time to complete this project, so if it an extremely cold day, it's probably not a good time to try pulling off this project, since you won't be able to heat your home during this time. The entire project took me about 5 hours, give or take. Some of which was discovering I needed additional hardware, e.g. new bypass duct, wire nuts, wire ties, etc..., so trips to the store added more time to it. I had to pick up a few things to do the tasks necessary to complete the installation. I purchased a metal cutting jigsaw blade to make the existing cut larger for the AprilAire 400, 100ft of 2-conductor solid 20 gauge wire (tried to find stranded, but wasn't able to in a reasonable gauge and length), a small tube of silicon sealant to seal up the hole I was to drill through to the outside for the temperature sensor, a drill bit designed for drilling through masonry/brick (ensure it is long enough!), a special hole cutting bit for metal (for the control sensor that's mounted on the return duct) - it was basically a round 3/4" piece, as required, with a main bit in the center to keep the drilling centered and accurate), some wire ties for wire management, a bag of wire nuts appropriate for the wire sizes being combined, a 6' length of expandable and flexible duct work for the bypass (from return duct to humidifier) - the existing piece was slightly too short to reach the new humidifier, so I opted to just replace it with something easier to work with.), and a roll of foil type duct tape (doesn't become brittle like regular duct tape). I already had: 1. Copper tubing for the water line 2. Wire stripper/cutter 3. Black & Decker 9.6V cordless drill/screwdriver 4. Copper tubing cutter (a device that is put around the tube and spun till it cuts it) 5. Existing 24V connection with a sufficient amp rating (from previous humidifier) 6. Sheet metal shears to cut where I could not use the jigsaw 7. A wood drilling bit (to drill through the floor a hole to run the outdoor temperature sensor) 8. Sheet metal screws from old humidifier mounting 9. Longer (3/4") sheet metal screws for mounting the control sensor to the supply duct 10. A jigsaw 11. Various other tools, i.e. wrenches and screwdrivers. The most challenging parts of the installation were feeding the outside temperature sensor through the outside wall and cutting the supply duct behind where the humidifier mounts. I did not have any existing holes to use on that side of the house. The other sides were either on the south or just too difficult to get to from the basement. The second most tedious part was cutting the existing humidifier's duct hole larger. I used the jigsaw where I could, but had to finish up quite a bit with sheet metal shears. Mounting of the saddle valve seemed almost too easy. I have a combo of mostly PVC and some copper piping. I opted to saddle on a hot water pipe just up from my water heater (about 4ft away), which is right next to the furnace anyway. I taped over the removed humidifier's screw holes to prevent air leakage. The old unit was shorter and wider than the new unit and had a much smaller duct opening behind it. A high level approach: 1. Run the outside temperature sensor 2. Disconnect power to HVAC system 3. Remove existing humidifier, if applies 4. Drill 3/4" hole in return duct to mount control sensor (adhering to distance requirements in booklet) 5. Run wires where they need to go per the control sensor instruction booklet 6. Tape up template on supply duct, being sure it is level,(install instruction page) and draw around it for where you need to cut and then cut it out. 7. Mount humidifier into new supply duct hole 8. Mount saddle valve. The instructions did not say to turn off the water supply for copper or PVC, but I did anyway. 9. Run copper tubing to humidifier's solenoid valve. Tighten per instructions. 10. Run copper tubing line to saddle valve and giving enough to work with, cut the tubing to length 11. Mount the copper tubing to the saddle valve 12. Wire the 24V as described in the manual. Be very careful with this part, it was a bit confusing to me at first. Look at the drawing to make better sense of it. 13. Connect your 1/2 inch inner diameter (I.D.) tubing to a drain or a condensation pump 14. Restore water flow - checking for leaks (check again after a while - often takes a while to develop some leaks, if they are small) 15. Restore power to the HVAC system 16. Test the unit per the instructions to ensure proper operation Notes: I experienced a very slight leak at the saddle valve. It was easy to fix by tightening everything, except the saddle mount itself. Be sure not to over tighten the actual mount, as it could crush the pipe. Just make sure it is tight and secure. It should NOT easily slide if mounted well. The leak I experienced was at the actual compression connection of the tubing. I had to use the sheet metal shears when cutting parts of the rectangle behind the humidifier mostly because the cooling coil sitting behind this area had some coolant tubing that was too close to the area being cut. Had I used the jigsaw entirely, I would have damaged the cooling tubes. Be careful with this. This review may contain errors, for which I apologize for in advance and I assume no responsibility or liability. Be sure to read your instructions thoroughly. It is recommended that a qualified HVAC installer handle the installation. My order of events reflect my actual order of events, but some things could likely be done in a different order. When in doubt, have a professional do it.

The '2' rating for 'Easy to install' lies inherent in the general knowledge needed, executing a number of trade-tasks: Electric, plumbing, HVAC It's a well made humidifier, nicely packaged, relatively easy to understand install instructions for the handyman type. Several great customization features that work very well with my furnace. The digital controller is intuitive, allowing me to modify features 'at will' quickly. Installing the humidifier 'level' is very important. Note: Check for 'plumb' on the metal venting you are mounting the humidifier to or you may have issues later, depending on the model you purchased. This review is for the 400 series.

I'm fairly handy as a homeowner, so I did the installation work myself. I followed the wiring diagrams provided, however, it would not work right (it was turning the A/C on). I hired a Professional contractor, who reviewed how I had it wired, and agreed it was wired correctly, per the book. After a while, we agreed it needed an isolation relay. He installed it, and it worked. If it were not for this issue, I would have given it a 5 star. It took some trial and error to get the setting right so it would not cause moisture to condense on the windows, but we have it set at 6, and it works perfectly. It does run a lot, but I have never found water draining. I normally flip the evap insert in the middle of winter and replace it each year. Great product, I would buy it again.

Went together easier than I expected. Took about 2 hours to install, and it worked the first time I flipped it on. I spent an extra $40 on install supplies. I had the tools needed, thankfully. I thought the wiring into the furnace would be a pain, but it all went together rather easily. I didn't even hit any bumps. Honestly, I enjoy doing DIY projects and find overcoming problems in the process very satisfying. After I had everything installed and turned it on, it just worked. It was honestly a little disapointing. I was looking forward to spending the afternoon working out kinks, or coming up with a neat solution. But it just worked. Exactly how it was supposed to. So then I spent the rest of the afternoon monitoring the humidity, but that was rather boring. The best thing about the unit is it keeps the temperature in my home really consistent from room to room. This is really just a side affect of it engaging the fan without the heat to add additional humidity. But through the process it circulates the air more and keeps my basement just a few degrees cooler than my main floor. I kinda like that. Plus now that the humidity in my home is above 16%, i can keep the thermostat set lower. Pros: Installed Easier than it looked, works well, automatic adjustment of humidity, Doesn't waste any water, circulates air in my home. Cons: Too easy to install. I was looking forward to a rigorous afternoon of troubleshooting and problem solving. But instead I had the whole rest of the day to my damn self.