Humidifiers come up constantly in our conversations with homeowners across the Denver Metro area — and it makes total sense.
Colorado is dry and the air is thin, especially in winter, and unlike most of the country we’re trying to add moisture to our homes, not remove it.
This year though, with 96% of Colorado under some level of drought conditions, the conversation has taken on a new layer worth talking about openly.
I recently sat down with my co-founder Xerxes Steirer, PhD — the building science brain behind Just Heat Pumps — to record a video podcast episode on exactly this topic. In this article, I’d like to share the key takeaways in a way that’s actually useful when you’re making decisions about your home. Let’s get into it!
Here’s the video also if you prefer to watch!
The Main Types of Humidifiers
As Xerxes puts it, “all humidifiers are not equal” — and knowing the differences matters a lot for Colorado homeowners. Here’s a quick rundown:
Bypass humidifier — the most common type we find in Denver Metro basements. It diverts air over a wet evaporative pad and pushes humidity into your supply duct. Lowest upfront cost (a few hundred dollars, 24V connection, no big electrical work). The catch: it continuously flows water over the pad, with the excess draining away constantly.
Water-saving bypass — same concept, but with a small recirculating pump that sends runoff back over the pad instead of straight down the drain. Cuts water waste roughly in half. Not much more expensive, and a meaningfully better choice.
Fan-powered humidifier — similar to the bypass but with its own fan. Slightly more efficient in airflow, but same water waste story overall.
Steam-generating humidifier — the premium option. Uses an electric heating element to boil water and produce steam directly. Near-zero water waste because essentially all the water that enters becomes steam. The trade-off: significantly higher equipment cost (3x–8x a bypass) and requires a dedicated 240-volt circuit, which adds to the electrical scope — something to factor in if you’re already electrifying your home.
Standalone room humidifier — don’t overlook these. A quality floor unit for a few hundred dollars gives you total visibility and control for one room or specific need. Just use distilled water — Colorado tap water is mineral-heavy and will coat your air filter and surfaces with white calcium dust if you don’t.
The Water (And Money) Waste Problem
This is the part of the conversation that really opens homeowners’ eyes. A standard bypass humidifier running at a normal 3–6 gallons per hour can send 10,000 to 25,000 gallons of water down the drain in a single heating season.
That’s not a worst case — that’s just how they work, by design. Even the water-saving bypass can still waste 5,000 to 15,000 gallons per season.
Not only that — this shows up on your water bill too. Those gallons really start to add up. And in a drought year like this one, with Denver Water restrictions back in place and water tables stressed across the state, it’s worth knowing what your humidifier is quietly doing in the background.
The steam generator is the only whole-home option that gets waste down close to zero. It costs more upfront, but the ongoing water savings are real — especially over the decade or two that humidifier will likely sit in your home.
Why Heat Pumps Change Things
This is something we talk about constantly as we install electrified heat pump systems across the Front Range: the traditional humidifier playbook was written for gas furnaces, and we can’t just copy-paste it to heat pumps.
A gas furnace pushes supply air at 170–190°F. A heat pump delivers closer to 130–140°F. That temperature difference directly affects how efficiently a bypass humidifier evaporates water off its pad.
Cooler air evaporates water more slowly — so you get less humidity than you’d expect, and more water going straight down the drain. We’ve also seen heat pump coils corrode through in under three years from bypass humidifiers splattering water into the supply duct rather than evaporating it properly. That’s an avoidable and expensive problem.
The steam generator sidesteps all of this because it has its own heat source — it doesn’t rely on supply air temperature at all. That’s a meaningful advantage in a heat pump home specifically.
What To Do If You Already Have One
Worth noting: roughly 9 out of 10 humidifiers we look at are either broken, not maintained, or both. So if you haven’t thought about yours in a while, here are the basics:
- Identify what type you have. Not sure? Send us a photo — happy to help.
- Check if it’s actually working when the heat runs. Many aren’t.
- Close the bypass damper in summer. Leaving it open wastes energy all cooling season.
- Turn it off in spring when heating season ends. Many homeowners forget.
- Maintain it annually — the evaporative pad needs regular replacement to avoid mold and mineral buildup.
- Lower your set point if you want to conserve water. Dropping from 45% down to 35–40% relative humidity is still comfortable and meaningfully reduces water flow.
A Simple Decision Framework
When a customer asks us about humidification, here’s roughly how Xerxes and I walk through it:
First — do you need whole-home humidification at all? Air sealing is often the smarter first investment. A blower door test can show how much dry outdoor air is infiltrating your home. Tightening the building envelope keeps your heated and humidified air in — and it saves on energy costs too. Every home is different, but it’s worth asking the question before adding equipment.
Second — what’s the actual goal? Comfort while sleeping? Protecting a piano or wood floors? One specific room? If it’s targeted, a quality standalone room humidifier may fully solve it without the water waste of a whole-home system.
Third — if you do want whole-home:
- Tightest budget → water-saving bypass (not standard bypass — the recirculating pump version)
- Best overall in a heat pump home → steam generator, if the budget and electrical panel support it
You can see how it just depends! But at least now you know what you’re choosing and why.
Wrapping It Up
Humidification in Colorado is more nuanced than it looks — and with the drought situation being what it is right now, it felt like the right time to have this conversation honestly.
We’re not here to guilt anyone. We just walk into a lot of basements, we see a lot of humidifiers quietly sending thousands of gallons down the drain, and we want homeowners to have the full picture.
A big thank you to Xerxes for sharing his expertise on this one — we’ll keep these conversations coming.
If you have questions about your existing humidifier, want to talk through options for your heat pump system, or just want to send a photo of whatever’s in your basement and ask “what is this thing?” — reach out to us here. We love chatting through these with you!
I hope this was helpful, at least for a start. Thanks so much for reading!
