One of the more common questions I get during a home inspection is How does my humidifier work? which is closely followed by Do I have to do anything to maintain it?
The humidifiers that are attached to modern furnaces in the Edmonton area are pretty simple appliances. They are attached to the cold air return side of the furnace which allows some of the air to pass through them before going back into the heat distribution system. You’ll notice an attached hose that brings in water from the cold-water supply, which supplies the moisture.
There are two standard types of humidifiers: Drum type and Trickle type (also called a Flow Through Humidifier). A Drum type humidifier has a pan of water that an evaporator pad rotates through. With a Trickle type, water is dropped from above onto the evaporator pad and trickles down to soak the whole pad.
When air passes through the humidifier, it flows across the evaporator pad which is a fancy way of saying it passes over a wet pad. The pad is already moist from the water supply. Moisture from the pad is drawn into the air and passed throughout the house, and there you have it. The air in your home becomes more humid.
The nice thing about them is that there’s very little that a homeowner needs to do to maintain their humidifier. The evaporator pad should be checked once a year, cleaned and changed if necessary and that’s about it. If you don’t clean the pad, then sediment that’s in our water will eventually build up and cover the pad to the point that air won’t be able to pass through it. At that point the humidifier is no longer functioning properly and will need to be replaced. Worse yet, some of that crusty sediment could be circulated through the furnace blower and into the home. So, cleaning or changing it before it gets to that point is important and fortunately, it’s quite simple.
Once you take the cover off, which is usually either a screw on the side or a clip-on top, you’ll see the wet (or crusty if it hasn’t been changed in a while) evaporator pad. For a Trickle type, the pad slides out and then back in again quite easily. For a Drum type, lift the drum off of its support and slide the pad off. It goes back in the same way it came out. Replace the cover and you’re done. It’s as simple as that. If you don’t know what kind of evaporator pad to buy, just take the old one to your local hardware store and they can help you find the proper one.
If you are planning on adding or replacing a humidifier and are wondering what style to get, I recommend getting a Trickle type humidifier. They may cost a bit more than a Drum type, but because they don’t have standing water in a pan, there is less risk of mould growing or other issues related to standing water.
Checking the evaporator pad on an annual basis is a simple and inexpensive way to extend the life and efficiency of your humidifier and will go a long way to improving the comfort level in your home.