108 of 108 people found the following review helpful:

Simple and Effective, December 27, 2010

This is my 3rd Aprilaire 600 and they were all worth every penny. (The 600 used to be called the 600A, now both are automatic and the 600′s electronics are slightly updated.) The 600 can be switched to manual mode, if desired.

My first unit was in my last house and was run for 2 years with no issues, then we moved. I just installed 2 in my current house (since I have 2 furnaces, 1 for each floor). I set it to humidity level #5 out of 7, which sets the relative humidity to 35% when the outdoor temperature is about 20 degrees F (details in the manual). The unit automatically turns on when the furnace is running and there is a call for more humidity. The unit can turn on your furnace blower in order to add humidity even when the furnace is not running, but I didn’t want that option, so I didn’t wire it in. If you do wire it in, there is a switch on the control unit so that you can turn it on or off.

Pros
* It’s automatic and comes with an outdoor temperature sensor. This allows the unit to automatically adjust the humidity level so that you don’t get condensation on your windows (condensation and the associated mold growth are why some home inspectors do not recommend humidifiers.)
* For us, it reduces nose bleeds and sinus infections.
* No standing water for mold to grow in. No individual room units to clean and refill.
* Works great, turn it on as the weather starts to get cold (also turn on the water to it and turn the lever to open the built in damper) and turn it off as the weather warms up.
* Low maintenance: Replace the water panel 1 time per year
* Low repair costs: There’s no fan or extraneous parts. The only moving part is the valve that turns on and off the water. The value is quick and cheap to replace if it ever builds up enough sediment or mineralization to impede function.
* Low upkeep: The manual says to replace the water distribution tray and valve solenoid every ~5 years. All the parts are easy to access and relatively cheap. After 2 years my original water distribution tray showed no wear and I don’t think it will really need to be replaced.
* Integrates with the electrical power in your furnace, so there’s no extra wiring (assuming your furnace is new enough to have the jumpers.)
* Completely silent.
* Uses almost no electricity
* I did not notice a decrease in air flow coming out of vents throughout the house.
* Easy to install if you are handy. Our local Heating guys charge about $450 to install these and it only takes them 2 hours. I did it myself in about 4-6 hours. All the tools you really need are sheet metal snips, a good drill to put in sheet metal screws, a wrench for tightening plumbing connections, wire strippers, and ideally a 3/4″ metal drill bit to install the electronic control. Installation instructions are included in the box, including wiring instructions. The instructions aren’t idiot proof, but they’re easy to follow for a handy person.

Cons
* Some water is wasted as unevaporated water does drain out the bottom. While I don’t want water wasted, I actually think this is a preferable design. I don’t want to waste electricity heating the water to create steam and I don’t want a tray of standing water for mold or bacteria to grow in (the 400 model has a tray of standing water and no drain, but is otherwise the same as the 600.) I haven’t noticed a change in my water bill since installing these units.
* A drain is required. I directed mine into my air conditioner’s condensation drain which feeds to the sump pump. No problem. It it’s a problem for you, try the 400 model.

Function
The unit works by taking air that has been heated by your furnace and passes it through a panel that has a small amount of water running across it. The water panel looks a bit like a radiator. The water on the panel evaporates into the hot air and gets distributed through your existing ductwork. That’s it, nothing fancy. Note that, just like any humidifier, the unit is more efficient if you connect it to hot water rather than cold.

If you decide to install it yourself and go against the recommendation to have a professional do it, you’ll also need the following:
#8 sheet metal screws
1/4″ copper water line
1/2″ ID clear vinyl tubing for drain
Clamp to attach the vinyl drain tubing to the humidifier
Small wire nuts
6″ start collar for bypass connection
6″ 90 degree elbow(s) for bypass connection
6″ pipe for bypass connection
18-2 thermostat wire (a few feet of 18-5 may be helpful to go between the humidifier and your furnace, but 18-2 will work there as well)
Depending on your furnace, 2 quick disconnect electrical plugs may be needed to connect the included transformer to your furnace’s power.
If furnace circuit board does not include humidifier…

Read more

]]>