How can I humidify a room without a humidifier?

  • It's winter, it's cold, and the heat is constantly blasting throughout my house. This is making the air very dry and uncomfortable to breathe, particularly at night when I'm trying to sleep.

    Are there any decent ways to humidify my bedroom without actually buying a humidifier? The only one I'm really aware of is running the shower with hot water, but I don't want to leave that much water running overnight. Plus, I don't sleep in the bathroom.

    I live in a 2 story house and in the winter I make sure to keep all doors shut. I heat my living room that way but not my bedroom, it will be cold but comfortable under the sheets.

    You should consider putting some better thermal insulation on your house. And in many rooms (kitchen, bedroom, ...) the temperature doesn't need to be above 18 °C. Both tips save money in the long run (depending on energy prices).

    Close the shower drain with a stopper or a towel. Then fill the base with a couple inches of water and leave the door open.

    Seal (water-tight) all your doors and windows and then bust a pipe.

    Crap, this Q is protected so I can't post an answer. I had the same issue as you, so I went out and bought 4 or 5 of these. - They come with a silver laced wick but once they run out, you can just chuck them and they work exactly the same. Just need to keep the water topped up.

    @TechnikEmpire So protection did what it was supposed to... "Buy a bunch of humidifiers" is *not* an answer to "How can I humidify a room without a humidifier?"

    @DavidRicherby It's not a humidifier, it's a plastic bucket that holds water and exploits your already existing vents to help it evaporate faster. It doesn't plug into the wall. Upvoted answers in here including buying pots and plastic buckets to hold water to let it evaporate into the air. A wooden box car is a car, my Mazda is a car, only one is an automobile.

    Why do you not want to buy a humidifier? I see several answers suggesting using a tea kettle or a rice cooker to boil water. Yes, this works, but it's way more expensive than buying a humidifier. Putting a bucket of water on a radiator or heating duct works and is cheap but isn't very effective.

    Maybe I'll decide buying a humidifier is the best option. But before I spend the money for multiple rooms in my house, I want to hear about alternatives. That's the point of this site, right... learning alternative solutions to problems?

  • Hang out your laundry to line dry in your house rather than putting it in the dryer. This will release a lot of moisture into the air. Depending on how often you wash your clothes, this may be enough.

    If it isn't a few damp teatowels hung on radiators (assuming they're not electric) will achieve the same effect.

    Why "assuming they're not electric"? I immediately think "water conducts electricity", but the outer shell of an electric-heater radiator is not actually electrified, so that's not relevant. What's the problem here?

    @MasonWheeler The element inside an electric radiator gets hot enough to combust stuff sitting too near it. Hot water radiators do not.

    It's really important not to *ever* cover any kind of electric heater. They can and will trap heat to the point that they combust. Putting anything even slightly wet near high voltage electrical appliances not designed for it is doubly risky.

    LPT: Don't burn your house down.

    I used to do this in a very cold climate, it does work. But I didn't do laundry every day, so I would take bath towels, spray them a bit with the handheld shower (you *do* have one of those, don't you?) and then hang them in the bedroom, usually a couple hours before bedtime. By morning they would be dry. Use old towels for this because a buildup of lime and other water deposits will ruin the towels pretty quickly.

  • 'Traditional' humidifiers look like this:


    It's just a ceramic container with a hook that hangs over the radiator. Fill it with water, and the water evaporates as the radiator heats it.

    You can emulate this with a dish or bowl hanging on your radiator. If you have the space the easiest option is to place a container on top of the radiator.

    It was not uncommon to add scents to the water, like lavender; this supposedly helped combat the 'stuffiness' of the room.

    A minor correction is what heat from radiator isn't just to boost an evaporation but importantly to stir the air moving water saturated hot air away from the liquid.

    Perhaps in newer, more airtight, houses things are different, but the humidifier in my small 1300 sf. house needs to evaporate gallons of water per day to keep the humidity reasonable in the dead of winter. A little container like this wouldn't make a bit of difference.

    I have a late-1800's house, and a tray or two of water on top of my radiators makes a devinite difference in indoor humidity. If you really have enough airflow that this an't help you, you _need_ to invesT a small amount of money in air-sealing the house; it's the best eergy-saving investment you can make.

    I'm sure the temperature of the outside air is a major factor in the water use of any humidifier. Mine only uses about a pint a day to keep the humidity above 40%, but I live in Arizona where the outside air probably averages 60F in the winter.

    Most houses in the USA built within the last 40 years don't use radiators (iow: have central air HVAC systems). The only building I can think of that I'm ever in on a regular basis that could possibly make use of this suggestion is my church.

  • You can put many houseplants in the room, they will increase the humidity naturally. Take some pots with plants which have big leaves.

    Some examples:



    Spathiphyllum (Peace Lily)

    Peace lily

    Additional positive effect will be that they will absorb some unhealthy substances from the air indoor.

    Of course they will need to be watered regularly.

    Plants in a bedroom, unless with open windows, is generally not a good idea. With sunlight, plants generate oxygen. However, without sunlight that's an entirely different story. Surely you won't suffocate, but it will have a noticeable effect on your sleeping comfort.

    @StephanBijzitter The amount of oxygen consumed by the plants during the night is negligible and it will not have effect on sleeping comfort. Actually plants reduce levels of benzene and formaldehyde in the room and will have positive effect on sleeping

    @StephanBijzitter Do you have a source for the claim that it would, "*have a noticeable effect on your sleeping comfort*"?

    Just note that lilies are deadly poison, and cats and small children are especially at risk (both more prone than most household members to eat plants).

    Spathiphyllum is not so much toxic as other lilies, but don't let animals or children eat it.

    @ErikE Spathiphyllum isn't a true lily (Lilium spp.) So it's mildly toxic to humans and animals when ingested. But yeah, better not feed your pets and kids with it.

    Sure... if you water them. They're basically the living equivalent of wet towels.

  • If the room is small, you can create a solution using a bucket of water and a few kg of table salt (sodium chloride or potassium chloride).

    Dump a large amount of salt into the bucket, and add water until the salt will absorb no more water. This is what's called a saturated salt solution.

    The solution will attempt to maintain the humidity level of the room at around 75%.

    Additionally, you can use a bucket of water, a towel and a fan to do this more easily.

    Joining LH to say what: **Saturated salt solution is the only smart way** to do as OP asked. Inventing anything that is more complex than primitive humidifier (see the water container on the radiator) is little weird.

    Just to nitpick--you could add as much water as you want to a bucket full of salt (assuming the bucket is big enough). To reliably saturate, you add the water, and THEN add the salt, and keep stirring and adding salt until the salt ceases to dissolve.

    Just wanted to mention to NOT use the saturated salt method mentioned above. That will DEhumidify the room, not humidity it, as the original poster requested. The partial pressure of the water molecules in the air will be greater than the partial pressure of the water generated by the salt solution, so the saturated salt solution will take in airborne water, not give it out.

    @DavePeterschmidt is there not a point in the concentration of the solution when the partial pressures equalize? Does this mean that oceans dry the air (or would do if the evaporative forces of sun and wind were not present)?

    "Dump a large amount of salt into the bucket, and add water until the salt will absorb no more water." That doesn't make sense. There's a limit to how much salt a bucket of water can absorb, and _that_ creates a saturated solution. But any given amount of salt can be absorbed into an unbounded amount of water: you can just keep adding water to it.

    Physicist here. Joined LH to upvote @DavePeterschmidt's comment: this is a *de*humidifier. The salt wants to be more hydrated than it is, so it will try to suck water out of the air. If the air is dry it will fail to do so and put moisture into the air instead (eventually resulting in ~75% humidity as the answer says) but it will do so slower and less effectively than if you just put water in the bucket without salt. (That would eventually result in 100% humidity, though of course that won't really happen, since new dry air will leak in to the room.)

    Is @kris suggesting this approach perhaps because the salt solution helps prevent *over* humidification? (i.e. The saturated salt solution will allow humidity to climb to 75% and try to prevent it from climbing above that vs. pure water which will equilibrate higher with a theoretical max at 100% - recognizing that both will yield lower humidification due to new dry air.)

    Thanks for the replies. This is the method we use for calibrating humidity probes, and occurs at quite a small scale. Adding humidity takes much longer than removing it (using lithium chloride). However as a passive system it's quiet and will maintain itself for many years.

    So many people misunderstanding here... The salt solution would only absorb humidity if the air is moist. A "dry" room's H2O partial pressure is lower than the equilibrium vapor pressure of the solution. Kudos to @Kris for this smart solution, but I might still use pure water, that is just enough even in such a damp country in Malaysia.

    Honestly, I'm much more worried about what happens to my floors when someone trips over that bucket. Soaked carpet or floorboards would certainly act to humidify the room nicely, but I don't think that's a desirable solution.

  • Large bowl of water in the room with you.

    I do this when the kids have stuffy noses/colds.

    Very minor nitpick: bowls tend to have smaller bases than the top, which makes them easier to tip accidentally. A (cylindrical) pot would achieve the same effect and be less prone to tipping over.

    Specifically, set the bowl in front of the heat vent or on top of the radiator. And if you have hard water, use something cheap and disposable, as the deposits from the evaporating water will do unfortunate things to the container.

    if you float a couple of lit tea-lights in the water it'll help to circulate the air over the water. dogs' water bowls are good for this as they tend to have wide bases.

    @Spongman wouldn't the dog burn its nose?

  • Use a rice cooker full of water. Unlike most electric kettles it will continue to run even with the water boiling, but will turn off (or to a lower "keep warm" state) when the water runs out and the temperature goes above 100°C.

    You will need to be careful though; it can work too well and turn your walls into slush. Use a really small rice cooker unless it's a really large room.

    Running it dry is not safe. Don't rely on the switch cutting it off if it runs dry. At best the fail-safe fuse will blow and your appliance will no longer work. At worst...

  • Taking a bath, or just fill your bathtub with some water will keep your room humidified. Leave your bathroom door open after taking shower/bath to let the steam out and humidify your room.

  • My grandparents would set out trays of water in front of the (floor-level) ducts.

    I've noticed that a large aquarium functions as a humidifier.

    When I needed relief and didn't have a humidifer yet, I tried spraying water around the bricks of the fireplace.

    I've held a hot wet washcloth up to my face to breathe through. That helps as a warm compress for sinus pain and also provides humid breathing air.

    I'm upvoting this because we have floor-level ducts (unlike that highly-voted radiator answer) and we have to put water bowls down for pets anyway. Simply moving the pet water bowls near the ducts seems like an ideal solution.

  • Leave an electric kettle heating with water in it.

    If you do this, however, you'll have to be vigilant for condensation on cold walls (behind dressers and bedsteads, for instance) or runoff from sweating windows causing mold growth. The problems with your nose from dryness are nothing to what black mold will cause.

    and the kettle running out of water

    That's also a concern, but most electric kettles will automatically shut off if they run dry. Only those made rather a long time ago will lack that feature.

    @ZeissIkon: in the US, at least as of about 2010, plenty of cheap kettles (i.e. bottom-end models at a shop like Target) didn’t have an automatic shut-off. Moving there from the UK, where in my whole life I’d never seen one that didn’t, I was pretty shocked.

    This takes a lot of power, and a kettle without auto-shutoff runs the risk of running dry and then melting.

    @PeterLeFanuLumsdaine Auto shut-off on kettles usually relies on the steam that's generated heating a bimetallic strip. If you use such a kettle with the lid open, the strip isn't bathed in steam so it doesn't trigger and the kettle will keep boiling. However, **DO NOT DO THIS. IT IS EXTREMELY DANGEROUS. YOUR HOUSE WILL NOT FEEL HUMID WHEN IT IS ON FIRE,** even though water is one of the combustion products of organic matter.

    @PeterLeFanuLumsdaine By the way, I'm pretty sure that an automatic shut-off mechanism is a legal requirement for electric kettles in the UK, which explains why neither of us has never seen one without that feature.

    @DavidRicherby Absolutely, and NEVER trust the auto-shutoff, it is a convenience, not life-saving equipment. Mine stopped working reliably after 3 years. There is a fail-safe overheat fuse, but then the kettle won't work at all after that.

  • I'm going to elaborate on Umber Ferrule's answer. Since my estate is rather cheap, I can afford to dedicate a couple of square feet to pretty large polyethylene basin like this:

    Several things to consider:

    • evaporation happens at the surface of water, so area is significant parameter here (this makes square bowl/basin much better than round one)
    • it works best at open space with air circulation present allowing humid and dry air to mix freely

    Although this could conceivably involve having to purchase an item, plenty of people also having something like this laying around. We use this method where I live, and it works quite well!

    Even having to buy one of these is way cheaper than the electricity required for a rice cooker or electric kettle that runs 24/7...

    @Alexander - until someone inevitably trips over it, and you have to replace your flooring.

    If you have a hospital stay, they will usually give you a plastic basin like this for free. Toothbrush, paste and deodorant too!

License under CC-BY-SA with attribution

Content dated before 7/24/2021 11:53 AM