Get the facts about how to test and adjust home humidity levels—for your health and your house’s.
If you’re reading this in your spare time, it likely means that something about your house’s air isn’t right.
Either your home feels stuffy and unpleasant much of the time or the air just seems really dry.
In other words, something about the moisture level—the humidity—in your home’s air isn’t comfortable.
If that’s why you’re here, well, it’s really good that you’re looking into it, and not just for the reasons you expect.
Bonus: If you work with us, you can get the right permanent fixes for these issues at no upfront cost. Tap here to see if you qualify for Sealed.
Key points in this article:
- A humidity level that’s too high or too low doesn’t just affect your family’s comfort—it’s also about the health and longevity of your home. Plus, it’s also a sign your home is likely wasting lots of energy.
- It’s important to know just how humid your house is and which practical steps you can take as a homeowner to adjust that humidity level.
- Many of the same long-term solutions for excessively humid air can make your home more efficient year round and boost comfort and air quality.
- Learn how to check your house’s humidity levels, as well as the specifics of a two-step fix to achieve ideal indoor humidity levels below in this article.
We’ve seen a lot of homes here at Sealed—and diagnosed plenty of humidity issues.
So we’ve got the facts about how to test and adjust humidity levels so that all the resident humans (and pets!) are happy and healthy—and your home lasts as long as it can.
Ready? Let’s dive in.
Table of contents:
- What is normal humidity in a house?
- How to check your home’s humidity levels
- 3 signs your home’s humidity is too low
- 5 signs your home’s humidity is too high
- The 2 main reasons your home has humidity issues
- How to stop unwanted air and temperature exchange
- The HVAC system that helps maintain healthy indoor humidity year round
- Permanently fix your home’s stuffy air at no upfront cost
First, what is normal humidity in a house?
So, what is “normal humidity,” anyway?
In truth, that phrase is a bit of a misnomer. There’s really no one perfect humidity level, because the right humidity level for your home depends on:
- What season it is
- Where you’re located, and
- What makes the people in your house feel most comfortable
(And is 65% humidity too high in a house? Definitely. In fact, you want to get your humidity to less than 60% in the summer—more than that and things are going to be unpleasantly sticky.)
By the way, if you slept through meteorology class—and, hey, didn’t we all?—a quick definition:
Relative humidity is just a measurement that tells us how much moisture is in the air compared to how much moisture the air can hold. It’s always stated as a percentage.
100% humidity means that the air is holding the maximum amount of water that it can—and 0% would mean the air is completely dry (3).
Those are the pertinent numbers, but of course… numbers don’t mean much by themselves.
How do you actually check to see if your house falls within them?
How to check your home’s humidity levels
You can keep an eye on your home’s humidity levels in two ways—the scientific way and the common sense way. Both are useful, depending on what you need.
Here’s a quick rundown of both:
- The scientific way: Measure with a hygrometer
- The common sense way: Check for known symptoms
The scientific way? Verify ideal indoor humidity with a hygrometer
Obviously, the most accurate way to check humidity is to get the tool that’s meant to measure it—in this case, a hygrometer.
That said, luxury is probably unnecessary here. You can get a just-the-basics working hygrometer for less than $20 (and you might even be able to borrow one for free from your local home tool lending library) (4).
How do you use a hygrometer? Well—follow the manufacturer’s instructions, obviously, but in general, the steps look like this:
- Install the hygrometer about 5′ above the surface of the floor (5).
- Wait a bit. Each hygrometer is a little different, but just about every home-grade hygrometer requires a waiting period of at least a few minutes (and sometimes up to an hour).
- Check the reading. Jot the number down, as well as the time.
- Check again at different times of the day or night. (This step is optional and is often overlooked! But it’s important to get a good sense of your situation.)
- Move to another part of your house—and repeat the whole process. Many houses circulate air unevenly, and testing humidity levels throughout your home can help you understand where your HVAC system is going wrong or where your house isn’t keeping conditioned air inside. (More on all that later.)
Many houses circulate air unevenly, and testing humidity levels throughout your home can help you understand where your HVAC system is going wrong.
What if you don’t need a specific measurement? What if you just want to verify that your house isn’t keeping humidity at a reasonable level?
In that case, here’s another, more old-fashioned way to check humidity levels.
How to check your home humidity—the DIY way
If you don’t feel like using a hygrometer—no judgment here—you can look for some common signs to see whether the humidity is too low or too high.
Common signs your home’s humidity is too low
- Constant static shocks
- Really dry skin and nasal passages
- Houseplants regularly drying out
Constant static shocks
We’ll spare you the “shocking experience” puns, but it is true that when humidity levels are too low, the air in your home will conduct electricity… a little too well.
If you’re starting to cut a wide berth around other inhabitants in your home for fear of being shocked, that’s a good sign that the air in your home is a little too dry.
Really dry skin and nasal passages
If the humidity is dry, you may be able to feel it in your hands, your face, and… yes… up your nose.
That’s because the air in your home is literally drawing moisture out of your nasal passages, leaving them dry and irritated. Some folks are more prone to low humidity skin problems than others, but it’s not great for anyone’s health or general well-being (6).
Plants constantly drying out
Plants are like little air moisture sensors. They won’t give you a number reading, of course, but if the humidity in your house is too low, you’ll find that they dry out quickly, crisp up at the edges, and generally look slightly miserable. Pay attention!
That’s how you can spot-check if humidity is too low.
And what about the opposite problem?
Common signs your home’s humidity is too high
- The ice cube test
- Peeling paint or wallpaper or wet walls
- The bread in your house is growing mold
- You detect moisture odors
- You feel stuffy
Try the ice-cube test
First, a quick and time-tested way to see if your home’s humidity is too high is the ice cube test.
To perform the test, fill a glass with a handful of ice cubes—then set it somewhere in your house that’s not the kitchen or bathroom (those rooms are constantly fluctuating in humidity, so you won’t get a fair reading).
Let the glass sit for three minutes—and then check.
If you can see droplets of condensation forming on the outside of the glass after only a few minutes, that’s a sure sign your home’s humidity levels are too high. Nifty, right?
The ice cube test is useful—and free!—but it’s not the only way to tell. Here are a few other common signs.
Peeling paint or wallpaper or walls that feel wet
When the air in your home is just a little too humid, that moisture can start to take its toll on any wallpaper or paint in your home.
Over time, you might even start to see it bubble and peel—not great for design, and definitely not great for your health if the paint contains lead or other toxins.
Another sign? Condensation or drips on your walls that are most often seen after a shower in a bathroom with poor ventilation.
The bread in your house is constantly growing mold
If you’re keeping your bread in a sealed container, and it’s still constantly growing mold, then that’s another sign that the humidity around your house is out of control.
You detect moisture odors
High-humidity air often has a certain smell to it—musty, almost like wet wood or wet cotton. If you start to detect that smell in your house (or your basement or crawl space), then it’s a good sign that the humidity levels aren’t great.
You generally feel stuffy
Pay attention to your instincts. High humidity doesn’t feel good—especially when it’s also hot outside. If you feel like the air around your house is just a little too thick, then you’re likely correct.
And it’s time to do something about it.
But first, we really need to address the large, irritating problem in the room: why the humidity in your home is out of whack in the first place.
As it turns out, there are a few ways to answer that question.
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The two actual reasons you don’t have ideal indoor humidity
So why is your house too humid? On the surface, the answer is simple:
Your house’s humidity is hugely affected by the environment:
- Around your home (because of the weather patterns and seasons as well as the natural moisture levels in the soil where you live), and
- Inside your home (with the moisture you and your family create by cooking, showering, and doing other necessary life stuff that involves water)
But—brace yourself—we’re going to officially disqualify environmental humidity as a factor.
Why? Because in the 21st century, there’s no reason that a house can’t maintain a healthy indoor humidity no matter what’s going on outside or inside—that’s its literal job.
And with the new technology and home weatherization knowledge available right now, there’s no reason any house should fail at that task. (Really. Even a large, old, cranky house. And yes, even if you live in Houston, Texas, or Orlando, Florida.)
In the 21st century, there’s no reason that a house can’t maintain a healthy indoor humidity no matter what’s going on outside.
So with environmental factors firmly set aside, let’s ask a slightly different question:
Why isn’t your house maintaining healthy humidity?
The answer to that is twofold:
- Your house isn’t keeping outside air outside
- Your HVAC isn’t up to the humidity challenge
Factor #1: Outside air is getting into your house
Your house needs to keep the weather outside from getting inside—that’s its job.
If that’s not happening, that’s probably because your house’s thermal barrier isn’t up to the challenge.
By the way, thermal barrier is just a fancy term for the boundary that separates the inside of your house from whatever’s going on outside. Here’s a 30-second-ish explanation.
If holes are in your thermal barrier—or if it was never properly constructed in the first place—outside air can get into your house and really throw off the humidity.
And if you’re wondering whether holes and leaks are in your house’s thermal barrier, the answer is yes… lots of them.
According to ENERGY STAR, air leaks account for up to 40% of your home’s heating and cooling energy waste (7).
This is an extremely common problem in the U.S.—and if your home isn’t brand-new construction, and if you haven’t sealed it recently, it’s probably affecting you.
Air leaks account for up to 40% of your home’s heating and cooling energy waste.ENERGY STAR
(Want to know for sure if air leaks are part of your humidity problem? Here’s how to do a DIY air leak check.)
How can you fix an air leak issue?
There’s really no way around it: If you want to permanently solve your air leak issue, you’ll need to take a couple steps.
- Get your home professionally air sealed
- Stop unwanted air and temperature exchange with proper insulation
Getting your home professionally air sealed
Air sealing just means closing off all the holes and air gaps that are making you and your family miserable. You can get a complete overview on air sealing here, but for now just know that it’s a game-changer.
Also a fair warning: Air sealing is one of those DIY projects that begins as a great, “I’ll do this in an afternoon!” project, and then turns into a months-long nightmare.
Unless you like spiders, attics, and crawling around on your hands and knees in an inch of dust and who knows what, save yourself and your most important relationships by hiring a professional.
If you’ve ever seen a “weekend project” turn into a 6+ month slog, you know how valuable efficiency and expertise is when it comes to home improvement.
Stopping unwanted air and temperature exchange with proper insulation
Don’t panic. You probably won’t need to tear out all your drywall and re-insulate the whole house.
What’s necessary here is something much simpler: Making sure your attic and foundation are completely insulated—and with the right kind of insulation.
You can learn exactly why in our complete guide to attic insulation, but—long story short—if there’s a lack of insulation in either your attic or your foundation (or both!) it can lead to a lot of air exchange at the top and bottom of your home.
And that can lead to a vicious cycle (literally!) in which outside air is actively sucked into your house.
This destroys any chance your HVAC has of keeping your air at the appropriate humidity making any humans, pets, or ghosts inside your house absolutely miserable.
(Well, maybe not ghosts, but you catch our drift—or, more accurately, draft.)
Need we say more?
Well, yes, actually because—speaking of HVAC!—there’s one more factor that could be leading to unpleasant humidity levels in your house.
Factor #2: Your HVAC isn’t doing its job
Here’s an inconvenient truth: If your home isn’t keeping humidity at a healthy level, your HVAC shares some (or a lot!) of the responsibility.
Now, a lot of things that can go wrong here—more than we have space to cover. Your HVAC might be too old, or it might be improperly sized. Or it could just be underperforming for another reason.
We’ve been in a lot of houses and, believe us, HVAC systems find many ways to go wrong.
But in just about every case, a poorly-functioning HVAC system leads to some kind of humidity control issue.
A poorly-functioning HVAC system leads to some kind of humidity control issue.
And even if your house’s humidity issue is not your HVAC system’s fault, it is taking a toll on your system. It has to kick on and off more to mitigate your home’s humidity, which overworks your system, wastes energy, and shortens your HVAC’s lifespan.
How do you fix that? What are the best ways to reduce humidity in a house (or even some ways to increase humidity indoors during a dry winter?)
Well, we’re glad you asked…
The HVAC you need to permanently get ideal indoor humidity levels
You can take two paths here.
The first is to make a few temporary fixes: adding dehumidifiers in summer, humidifiers in winter, and portable ACs to the mix to try to balance out the humidity in your home.
Make no mistake: These solutions can help—but know that they’re really just Band-Aids and they’ll often cost more in time, stress, and resources than they save.
Plus, they won’t make your real problem go away.
With Sealed, you can get a super-efficient, top-quality HVAC upgrade—and no upfront cost, keeping your hard-earned cash in the bank.
The permanent way to fix this issue? Upgrade your main HVAC system—preferably to a modern, super-efficient heat pump.
We know. No one likes spending money on HVAC.
But here’s the deal: To keep humidity levels balanced in a home, you need an HVAC system that works. Period.
But with Sealed, you can get a super-efficient, top-quality HVAC upgrade—and no upfront cost, keeping your hard-earned cash in the bank. See if you qualify.
Overall, the data is clear that the best HVAC for most folks in the US is an energy-efficient heat pump. If you haven’t heard of heat pumps, no worries. (Just tap over to our complete heat pump guide to get full details.)
For now, here’s why heat pumps are an upgrade you should consider to help fix your humidity issue:
- Heat pumps are an all-in-one HVAC solution, providing both heating and air conditioning
- They automatically manage your humidity year round—no separate appliances necessary
- They have lower lifecycle costs compared to conventional HVAC systems (8)
- They don’t dry out your indoor air in winter like a gas furnace or boiler
And if you’re thinking, Yes, yes, but what is this going to cost me—we have a couple thoughts.
First, if your new HVAC system is 3x more efficient than your existing heating and cooling appliances, you’re going to see that difference in your energy usage. Big time.
Those savings really add up over time (especially as energy costs rise).
Also, there’s significant investment value in making sure that your home is properly taken care of by its HVAC system. A highly-efficient HVAC can save you a lot of energy, but it can also save you money down the road.
(Mold remediation and fixing structural damage caused by moisture tends to be expensive).
And also, if you go with Sealed for your home upgrades, you can get a heat pump and air sealing and insulation for $0 money down. Learn how the Sealed payment plan stacks up.
In other words, if your house qualifies for a Sealed home makeover, you can completely fix your humidity without draining a bank account.
Permanently fix your home’s humidity. Zero stress (or upfront cost).
It can be intimidating to think about upgrading your home.
The positive here, though, is that—if your house qualifies—you can get the right upgrades to fix your humidity without the stress (or the hit to the wallet).
With Sealed, you can get energy upgrades like a heat pump water heater, attic insulation, professional air sealing, or a super-efficient heat pump HVAC system at zero upfront cost.
You pay us back for the work done with one of the flexible payment options that’s best for you.
Sounds too good to be true? It’s not. See how the Sealed payment plan works.
Answer a few questions here to see if your house qualifies.
I highly recommend [Sealed]! The installers were friendly, professional, answered my million questions, and really knew their job!Laurie S., Sealed customer