A dehumidifier is a device that removes excess moisture from air. In the home, dehumidifiers help keep mold, mildew, and fungi under control. Low humidity also helps electronics and fabrics. The kind of dehumidifier you can buy usually is a type of air conditioner or refrigerator that chills air, collects the moisture that drips, and re-warms the air. But, you can easily make a homemade dehumidifier using common household chemicals. Here are instructions for 7 homemade dehumidifiers.
Silica Gel Bead Homemade Dehumidifier
Silica gel packets come with shoes, electronics, and many other products. The little beads consist of a hygroscopic material. The silica gel has lots of tiny pores that attract and collect water. You can collect a bunch of packets or purchase silica gel.
- Pros: Readily available, no mess, re-usable
- Cons: Mostly effective for small volumes, like cabinets or boxes
- Place a bunch of packets where you want humidity control. Otherwise, dump silica gel into a porous container, like a sock.
- Some types of silica gel beads change color when they have absorbed all the water they can. It’s a guessing game with the clear beads unless you own a humidity sensor. Re-charge the beads by baking them in a warm oven (up to 180 °F or 82 °C) to drive off moisture.
Calcium Chloride Dehumidifier
Calcium chloride is a popular desiccant (drying agent) because it’s inexpensive, readily available, and safe. While you can buy calcium chloride by its chemical name, it’s also sold as “road salt.” This chemical absorbs so much water that it actually dissolves. So, you use it a bit differently from silica.
- Pros: Highly effective, inexpensive, dehumidifies an entire room
- Cons: Dissolves so you have to replace it, a bit messy
- Pour calcium chloride into a can with holes poked into it so water drains. Another option is pouring it into a sock or mesh bag.
- Place the can or bag over a bucket for water collection.
Over time, calcium chloride dissolves. Pour the water down the drain or use it to de-ice a driveway in winter, but don’t drink it or use it for watering your plants.
Charcoal Dehumidifier
Charcoal is porous and absorbs both odors and moisture. It’s a good choice for a bathroom, closet, or basement.
- Pros: Affordable, effective, also controls odors
- Cons: Requires replacement
- Place charcoal in a porous container, such as a sock or can with holes poked into it.
- Replace the charcoal every few months.
Rock Salt Dehumidifier
Salt absorbs water, which is why it clumps up inside salt shakes in humid environments. Rock salt dries out small rooms, making it perfect for closets or basements.
- Pros: Inexpensive, non-toxic
- Cons: Not as effective as calcium chloride, requires periodic replacement
- Place a decorative piece of rock salt in a room as a natural dehumidifier.
- If your salt is granular, pour it into a dish or bag. Place this onto or inside another container. The second container collects excess water.
Replace the salt once it dissolves. Pour the salt water down the drain. Don’t pour it on your lawn or garden.
Table Salt Dehumidifier
There’s nothing particularly special about rock salt except that it’s cheaper than table salt. Chemically, they are both mostly NaCl. The larger surface area of table salt crystals helps it work faster.
- Pros: Inexpensive, readily available, non-toxic
- Cons: Best for small spaces
- Place a dish of salt on the counter. If you place it inside a bag, put the bag inside a second container to capture water.
- Replace the salt once it dissolves.
You can extend the effectiveness of salt as a dehumidifier by mixing it with rice. Rice also keeps salt from clumping in salt shakers.
Baking Soda Dehumidifier
Like charcoal, baking soda controls both odors and humidity. Baking soda (sodium bicarbonate) works best in small areas, like the interior of a refrigerator or a cabinet.
- Pros: Inexpensive, non-toxic, effective
- Cons: Best for small spaces, like refrigerators or boxes
- Just open a box of baking soda and place it in the room.
- Replace baking soda when it forms a crust or hardens. This happens when it absorbs humidity.
Coffee Creamer Homemade Dehumidifier
The same chemicals that make coffee creamer or coffee whitener clump up in the container are the ones that act as safe dehumidifier. Mostly, it’s the dehydrated corn syrup that picks up water from air.
- Pros: Readily available, effective, non-toxic
- Cons: Relatively expensive, only good for small spaces, sticky when wet
- Pour coffee creamer into a dish and place the dish in a room.
- Replace the coffee creamer when it gets soft or sticky.
It should be obvious, but don’t use the creamer in your coffee after using it as a dehumidifier.
References
- Daou, K; Wang, Xia (2005). “Desiccant cooling air conditioning: a review”. Renewable and Sustainable Energy Reviews. 10 (2): 55–77. doi:10.1016/j.rser.2004.09.010
- Dziedzic, S. Z.; Kearsley, M. W. (1995). Handbook of Starch Hydrolysis Products and Their Derivatives. London: Blackie Academic & Professional. ISBN 978-0-7514-0269-8.
- Sakuma, Shuichi; Yamauchi, Shiro; Takai, Osamu (December 2010). “Estimation of dehumidifying performance of solid polymer electrolytic dehumidifier for practical application”. Journal of Applied Electrochemistry. Springer Nature. 40 (12): 2153–2160. doi:10.1007/s10800-010-0197-4
- Williams, D. B. G.; Lawton, M. (2010). “Drying of Organic Solvents: Quantitative Evaluation of the Efficiency of Several Desiccants.” The Journal of Organic Chemistry. 75: 8351. doi:10.1021/jo101589h
- Worthington, David (2003). Dictionary of Environmental Health. London: Spon Press. ISBN 0415267242.