Flow-Through Humidifiers

Need a new humidifier or is it time to upgrade?

About 15-20% of the homes we visit in the GTA still have the older drum-type humidifiers on their furnaces. And easily more than half the time they don’t work anyway. They’ve been disconnected because they were either leaking water all over the place or else the motor was making noise.

The older types usually have a yellow humidifer pad that turns in a tray full of water. The tray had to be completely level and the float had to be adjusted properly at the beginning of each heating season or every time the humidifier was cleaned. But since the process of setting it up properly each time was not always being done by many homeowners, they found that their humidifiers were constantly leaking water, which eventually lead to them turning off the water completely and just eliminating it’s use altogether.

The trend for the last 4 or 5 years has been to replace these humidifiers with a modern flow-through model. By flow-though, I mean a type of humidifier that does not store any water at all. Whatever water enters the new type of unit is either used for the humidification process or is discarded through a drain tube that is usually connected to your floor drain. If you already have central air conditioning, then there is already some type of drain tube present.

The only maintenance that is required for these new units is to replace the metal mesh pad inside it once per year. And that’s it! When we do this for our customers we usually clean out the bottom part of the unit anyway, and that removes any scale that may have collected there. We also turn the humidifier on and quickly check its operation. And then of course, we shine it up using a cleaner and a cloth. Changing the pad and giving the unit a quick once-over usually takes less than five minutes, and that is all the maintenance that it usually requires.

The flow-through model is way more efficient and is easier to maintain. It came about in the first place because of the concern that many people had regarding their drum-type humidifers holding water, and there was even some mention about the contents of that grimy water causing Legionaire’s Disease. We’ve seen some very scummy water in alot of these old humidifiers, and that can’t be healthy. Can the stagnant water in the trays of the old humidifiers really cause so many health problems for some people? That’s up to the experts to decide for certain, and as far as I know, that is the general concensus.

We checked out several types of these new humidifiers and determined that the General Air model was superior. Since that time we have been installing this make of humidifier exclusively. It’s made of sturdy plastic, so it will never rust. The water valve is electric, and it uses 24 volts that is supplied by the furnace. There are no moving parts in this humidifier at all, so it’s operation is silent. The only noise it makes is one ‘click’ sound when the water valve first comes on, but you’d have to be standing right beside the furnace to hear it.

General Air provides a one year warranty on all of their humidifiers and its parts. Whenever we install one of these units, we also warranty the complete installation for a year as well. So if there is ever any problem with your humidifier at all in the first year, we will come back and correct the problem absolutely free of charge.

The General Air humidifier is not sold in retail outlets, and is only available from heating wholesalers. There are some similar brands of humidifiers that can be bought at places like Home Depot or Canadian Tire. It’s certainly cheaper to buy one off the shelf and hook it up yourself if you know how. But we’ve seen many humidifiers that were not installed properly at all, in fact, the way some of them were installed would end up costing the homeowner money instead of saving money on heating.

Most humidifier replacement parts are standard, and it’s convenient that those parts are readily available at the same retailers, but in my opinion they are not really doing people any favors by selling them a complete humidifier. Installing a humidifier properly is something that should be left to a professional.

Some common mistakes that we see being made while installing a humidifier are:

1. Hooking up the 24v transformer to a nearby power supply such as an elecrical box that supplies a light socket. What this does is give the humidifier power all the time, therefore water would be constantly flowing through your humidifier and down the drain non-stop. This is equivalent to leaving a water tap on, and would also cost more in wasted water than a leaky toilet would.

The humidifier comes with the transformer because it is ready to be installed out-of-the-box in almost any furnace. Most furnaces are gas and operate on a 24 volt system anyway. If the power which supplies the new humidifier comes from the furnace like it should, then it’s only a matter of connecting the wires in the right place so that the humidifier can only come on if the furnace is actually calling for heat. If the heat is on, then your humidifier can be on too, but only if the humidity in the home is below whatever the humidistat is set at. And with the unit installed properly, it cannot come on if say your central air is on, or if everything else is off.

So basically, the transformer that comes in the box ends up being spare parts almost all the time. We have hundreds of these spare parts kicking around now, and are still looking for a way to recycle them. Save your extra 24v transformer, as you might need to replace the transformer for your doorbell one day!

2. Installing the water valve on the hot water pipe. The humidifier will still work, but it does it’s job more efficiently with cold water rather than hot. Whatever water is not used goes down the drain anyway, so why heat the water first?

3. Installing the water valve in the wrong position. The valve that is supplied is self-piercing and is clamped onto a half-inch water pipe. It will work if the valve is on the top, the side or the bottom of the pipe. But if it goes on the bottom of the pipe, the valve will get gummed-up within two years almost for sure, because in that position it will be more likely to be effected by the impurities in the water supply over time.

4. Not cutting a big enough hole for the humidifier by-pass tube. The tube is 6″ in diameter anyway, and a full-sized hole will allow the proper airflow through your humidifier.

A central humidifier can save you up to 10% off your heating bill if it is installed and used properly.

If you would like to have us install a new humidifier in your home or if you have any questions about your existing installations, please do not hesitate to contact us.

Also read : Rooftop HVAC Equipment