Many of us here in the arid west are doing our darndest to make the best use of our water – planting low-water-use plants, replacing shower heads and toilets with low-flow versions, collecting the water that runs out of the sink tap while waiting for it to heat, etc. Water use and conservation are somewhat big deals here.

Water (and energy) conservation is definitely a big deal to me. I even volunteer at the utility company’s xeriscape demonstration garden. So imagine my surprise (and embarrassment) when I discovered I’d brought a little talked about BIG waster of water into my home.furnace1.jpgLate last fall, we decided to replace our 30-year-old furnace. We’d always planned to have a whole-house humidifier installed when we replaced the furnace. The Colorado Springs area is quite arid, with humidity levels often too low in our house to be read by our little indoor weather station (it won’t read below 10% humidity). A whole-house humidifier seemed an easier way to try to add humidity than with smaller room-size units.

If you haven’t installed one of the new super efficient furnaces yet, you may be surprised to learn that they need to be able to drain away condensate (a.k.a. liquid). If you have a floor drain near your furnace, this is where the condensate will drain. We live in an old house with no floor drain, so we needed to install a pump to run the condensate across the basement and up to our old soapstone sink. The whole-house humidifier was installed to share the same pump and drain into our sink.

humidifier1.jpgOnce everything was installed, we happily set the humidity to 30% on our fancy new combination thermostat/humidistat and felt smug we wouldn’t have to be carrying buckets of water to little humidifiers around the house.
in the middle of the night……..
We kept hearing a low droning coming from the basement. The humidifier was running (the furnace wasn’t heating, but its blower was on) and creating enough excess water that the pump was running every two minutes for 20 seconds (believe me, I counted again and again). The next morning, we saw the sink had clogged a bit with lint from the previous week’s washing machine loads, and it was more than half filled with water! This is a BIG sink we’re talking about!

humidifier2.jpgSo we started measuring the water coming from the humidifier. We put a 3.5 gallon bucket in the sink under the drain tube. In a few hours, it was overflowing with water. When the furnace was running in the morning, it would create a few quarts of condensate. After emptying that, we could measure that the humidifier itself was dumping several gallons in a day. After a few days of letting it run day and night, we calculated we were sending around 15-to-20 gallons of water down the drain each day. Up to 600 gallons a month. Wow.

Our furnace installer wasn’t surprised at all that the humidifier was dumping that much water. In fact, he seemed rather amused that we were so upset about it. “Really, what you should be concerned with is saving electricity!” Well…ahem….can’t we be concerned with conserving electricity AND water? He convinced us to try it for a few months, promising that once the dry old house started to absorb humidity into its wood floors, plaster walls, etc., we’d probably notice a reduction in the amount of time the humidifier ran. He also suggested reducing the humidistat setting. If after a few months we were still unhappy, we should call them again.

We turned the humidistat down to 27% and turned the humidifier off completely at night. The pump was keeping us awake, both with its sound as well as the constant reminder that we were wasting water. With these adjustments, we were still sending about 10-plus gallons down the drain. It’s hard to know the exact number as the bucket was often overflowing when we checked it. We got quite diligent about carrying that heavy bucket outside when it was warm enough to put the water down on our lawn and other areas of the landscape.

I did a bit of research on humidifiers and found out ours (a Skutter brand model) was a flow-through type. Flow-through models require no maintenance on the part of the homeowner. Water flows down over an evaporative screen, and the excess that isn’t distributed through the home as humidity drains out the bottom. If you have a floor drain, you’ll see a stream of water dribbling down into it. If you don’t, the excess is pumped to wherever your washing machine drains. Some studies have found that up to 5-to-8 gallons of water is wasted for each gallon that is put into the air (eek!).

I was flabbergasted to discover that this sort of water waste was typical of the flow-through models. Why hadn’t I heard about this? Why weren’t people outraged or at least upset or, at the very least, talking about it? Well, it seems that most people have theirs draining directly to a little floor drain and they have absolutely no idea how much water is going down that drain. I started asking everyone I knew about their humidifiers, and most people said “Well I’m sure ours isn’t using that much water. It’s just a little trickle that goes down the drain.”

I’d done so much research into the furnace choices we had, but it never occurred to me that I needed to do the same sort of research into the humidifier options. In fact, the representative from our heating company didn’t even mention there were options. He just set us up with their most “popular” model. (Hmmm…is it popular because people actually ask for it or because it is installed by default?)

It’s now been five months since the furnace and humidifier were installed. I’m waiting for the heating company to get back to me with an estimate for replacing the flow-through humidifier with a different model – the Aprilaire 400 – which promises to use 100% of the water that goes into it by wicking the excess back up to the top for future use. I found out about this model in my after-the-fact humidifier research, and then I noticed this model being promoted on my furnace installer’s web page! (I love that the marketing materials say it is a good choice for people “interested” in water conservation. I’m interested! I’m interested!)

Lots of homes in the Colorado Springs area have whole house humidifiers. I’m still amazed that the Aprilaire 400, or something similar, isn’t the “default” model or least offered as an option to those embarking on a furnace/humidifier project. This model needs to have its pad replaced every six months – apparently this is “high maintenance” compared to the flow-through models, but I’m certainly up to the task if it means I can use water more efficiently.

So…how much water is YOUR humidifier putting down the drain?

January 2012 Update: Last September, I had our original humidifier replaced with an Aprilaire 400 (total cost about $200, sigh), and it has been working VERY well and very efficiently! Next weekend, we will do our first pad/filter replacement on it.