Because my home had a Geothermal heat pump system my solution was quite easy. The reason it was so easy was because the duct work, which was installed during my home construction, would provide a perfect means of transporting humidified air throughout my home. After researching all the different types of humidifiers I narrowed my solutions to two different types. The two types of whole house humidifiers that I decided would work were pad type humidifiers, and rotary disk humidifiers.
Whole House Pad Humidifiers
Pad humidifiers mount on the cold air return of your furnace. Prior to mounting the humidifier a hole is cut in the plenum (duct work) in order to allow cold air to pass through into a pad that is moistened with water. The air that passes through the moistened pad absorbs the moisture and is then passed through a hose into the warm air supply. The moistened air then travels through your duct work into all parts of your house.
There were two problems that I found with the pad type humidifier. First was the supply of water which flows over the pad does not completely absorb into the pad. The water that is not absorbed is then just flushed away to a floor drain. I found this to be wasteful especially if your are paying for public water. The second problem that I found was that you had to replace the pads, especially if you had hard water, on a regular basis. This humidifier pad replacement could become expensive in its self.
The one positive aspect of these types of humidifiers were the low up front cost. But after taking into consideration the problems I decided to move on to the rotary humidifier.
Whole House Rotary Disk Humidifiers
The Desert Springs humidifier seemed to be a much better solution. The installation is similar and took no more than a few hours to install. The one big advantage Desert Spring furnace humidifier had over the the pad humidifier is that there are are no cost for pad replacement. Another advantage of the Desert Springs humidifier is that the only water that is wasted is water that may become polluted due to hard water. I found at my house that a once a month flushing would do the trick and if you would like to automate this flushing procedure I would recommend the auto-flushing accessory.
The way the Desert Springs humidifier works is rather ingenuous. Basically there is a stack of flat rings, know as Rotary Disc Technology, placed on their side. The rings look like what a record would look like if you were to cut the center and leave a outer one inch band. The one inch portion of the ring is then submerged into a small bath of water. Then when the furnace kicks on, and humidity is required, the entire “tube” of rings begin to rotate. The air, from the warm supply side of the furnace, passes through a duct into the center of the stacked rings. The warm air then passes through the rings, which are coated with a thin layer of water, and is then passed into the cold air return. There are no pads to buy and no water is wasted.