Aprilaire Model 600 Automatic Whole-house Bypass Humidifier with Digital Control

Aprilaire Model 600 Automatic Whole-house Bypass Humidifier with Digital ControlThis is a highly sophisticated humidifier. I consider myself to be a fairly handy homeowner but after receiving the item and reading the directions I opted to pay a professional for the install. I am glad that I did. I had estimates in my area to do the install between $250 and $350 over the cost of the unit.
Everything on this unit is automatic. A hard wire runs outside of the house to monitor the outside air temperature.
The only question that I had before I bought the unit was weather the 3 gallons per hour of water ran 24/7 or not. The answer is that it does not. A solenoid only lets the water run when the unit needs to add humidity.
I am more satisfied with this product than I expected to be.

It's a great product and it works extremely well when set to full automatic. The outdoor temperature sensor needs to be installed for automatic mode for proper relative humidity and to avoid window condensation. Yeah it takes some time to install it properly but well worth it. When it's set to automatic it will actually kick on your blower periodically even without a call for heat to get an accurate check of the humidity levels and stay on if they are low. The automatic mode helps tremendously after the heat runs and it needs to stay on for a bit to keep the levels accurate. I also found this setup to be useful in reducing cold spots in the house and to help maintain even temperatures kind of like a 2-stage furnace would. With a flip of a switch it can be set to manual and will only run if there is a call for heat and humidity is required. If you're going to spend the time to install one of these, I wouldn't settle for a unit that is not automatic. The 24vac transformer that was sent with the unit was pretty cheap; I tried to loosen one of the terminals and it broke the lead. Not worth a phone call so I just picked up one at the hardware store for $13. If you plan on using this for automatic purposes, then the transformer should be powered with constant power. I ran power down from the furnace power switch to the blower compartment where I mounted the transformer. That's also nice because when you shut down the furnace via the switch it also shuts down the humidifier and adds protection with the onboard furnace fuse. You will want to wire the transformer at the switch and not from any wires or furnace electronics after the switch (excluding a designed HUM accessory power lead). Like many others my furnace's Honeywell circuit board is equipped with a HUM accessory power lead and on my unit it is 120V so don't think you can bypass the use of a transformer if that's the case. But if your board is similar to mine the HUM power lead will only work if you plan on using it in manual mode as it's only powered when there is a call for heat; it is not powered when there is only a call for the blower or no call at all. Obviously the unit will be more efficient when supplied with heated air; as will be the case most of the time. But there are several studies that show a sufficient amount of humidity will be applied by just the blower moving ambient air through the unit. The manual does state that when set to automatic mode then the unit should be supplied with hot water and in general that is a good practice for the MOST efficient way to evaporate water and help keep the impurities from building up over time. But I couldn't justify the usage of energy that it takes to make that water hot and watch it go down the drain. Some studies show that the benefit is insignificant in supplying hot water over cold water. It's going to be up to you but I couldn't do it and the unit still works very well when supplied with cold water. Hope this helps some of you out in the decision process and I posted a few pictures of the install.

I installed this product myself. I have a background in electrical work as I am a Master Electrician so I did not find it difficult to install. The make humidity it can put out is 45% I do not recall reading this anywhere online before purchasing. Has hoping to get the humidity up to 50-60% but upon further investigation going that high could ruin your house and create mold problems. I think if you do not have any mechanical background it is probably best to have a HVAC contractor install this product.

I purchased the aprilaire model 600 to replace my old sears humidifier on my new furnace. Three months ago I had a new coleman echelon furnace and air conditioner istalled and wanted a new humidifier to replace my 12 year old sears drum type unit. After some research I picked the Model 600 with automatic digital control.
First, if you are not handy or comfortable doing electrical wiring, hire a professional to install the humidifier. If you want to tackle the installation be prepared to spend the better part of a day to install. Not that the installation is very difficult or confusing but it is time consuming. there is some duct work, electical and wiring hook ups. Once installed it could'nt be easier to use. With the digital control you set the humidity level, and the unit will adjust itself with changes in the outside temp., set it and forget it! Maintenance is just as easy, replace the media pad once a year, a five minute job if you take your time! I would'nt hesitate to recommend this unit.

The humidity hasn't been low enough yet to actually run this yet so I can't comment on its effectiveness (will update review later). However, installation was fairly easy if you are somewhat handy. Wiring in to furnace was a breeze with included wiring diagram. I mounted the 24VAC transformer in a junction box on the side of the furnace. I installed the unit on the cold air return due to concerns raised in other reviews about water dripping down in to the furnace. I opted to not use the saddle valve and chop my hot water pipe and solder in a T with a ball valve instead (not a fan of saddle valves).

So like others mentioned... the install guide(s) are a bit crude. Install took me just over 3hrs to do. I piggy backed of the 24v supply already there for the furnace. Used the hot water line for best performance. The tough spots were tin snipping the openings (now i have increadible grip strength) and fitting the 6" flex duct hose (must be a trick to it i don't know) to the unit and the flange. Make sure your sheet metal screws are long enough as mounting holes on the unit are raised. I used an earlier review which had a check list of supplies needed for this project and for once didn't have to make two trips to the hardware store (thanks!).

Some tips: To get the unit to work without the temp sensor in place make sure you select manual on the Digital controller (otherwise water won't flow and error message will show). Make sure you get enough wire (@ $.23 a foot better to have extra then to waste gas and time going back). Finally make sure you are at least 6" upstream from your unit with the Control mounting otherwise you will get higher moisture readings.

I was able to turn down the temp in the house 2 degrees and still felt it was too hot in the house (2,500sqft). I am sure i will be getting returns on this for a long time not to mention how pleasant the house feels.

Aprilaire Model 600 Automatic Whole-house Bypass Humidifier with Digital Control

What a difference it is to wake up in the mourning and not have a dry mouth or stuffy nose.Would you look at that! The APRILAIRE 600 does just what the manufacturer addvertises. The item arrived on time and packaged very well. AMAZON has the best suppliers of all stores on the internet.Would you just look at that. Thanks Dave

This humidifier works great and it is relatively easy to install. Installation instructions are clear.

When I got this item and tried to install it myself, I was a bit intimidated by it. It was harder than I anticipated but that could be because I'm not so handy with items as such.

Had someone help who is a lot more handy and installation went smooth.

Helpful note: Requires cutting the air supply vents, requires providing power to this unit, and requires connecting this device into your furnace control panel.

Hook up is easy and you dial how much humidity you mant on the readout.I bought an extra filter and drain line had to go into the backwall of a sink drain.Follow the instuctions and there is a template for the big hole to cut in the furnace. I love this unit, no more Sahara Desert and scratch in winter. I recomend this unit more than my old honeywell unit at my other house. Its worth the comfort.

Easy to install and saved approx $400 by installing humidifier my self. Appears to be working as advertised. Highly recommend product.

I have not been able to get more than 25% humidity in my house. Dont know what is wrong,but unhappy with performance of this unit. Shipping was perfect. I am very happy with that side ofthis purchased.

I thought I'd be able to install this myself but this automatic model requires an HVAC technician to install it. I think the only reason it comes on is because of the outside temperature probe. They figure that since it's cold, the furnace must be on.. so the hunidifier turns on - makes no sense to me. It should only turn on when the furnace is on.
I would stay away from this model and buy the standard model with a manual control. Furnace on, then humidifier must come on... not based on outside temperature. Calls to Aprilaire support didn't help.