Humidity Controllers | McMaster-Carr

Filter by

Voltage

Relative Humidity

Display Type

Relative Humidity Accuracy

For Area

For Use With

Wire Connection

Component

Width

Material

Anhydrous Calcium Sulfate

Desiccant Material

Anhydrous Calcium Sulfate

For Removing

Mounting Location

Desiccant Type

Length

Container Type

RoHS

Compliant with Exemptions

Certification

UL Recognized Component

VDE Certified

REACH

Compliant

Not Compliant

U.S.–Mexico–Canada Agreement (USMCA) Qualifying

Yes

Export Control Classification Number (ECCN)

EAR99

Electrical Connection

Weight

DFARS Specialty Metals

Exempt

Electrical Connection Type

Height

87 Products

Panel-Mount Humidity Controllers

The sensors monitor relative humidity and trigger the controllers to turn equipment on or off. Sensors and controllers are sold separately.

Controllers

Controllers are SPDT (single pole, double throw). They can be set to turn one circuit from off to on (normally open) or from on to off (normally closed). Set the actuation point with the keypad.

Relative Humidity			For Panel Cutout		No. of
Range	Accuracy	Max. Operating Temp., ° F	Ht.	Wd.	Actuation Points	Circuits Controlled	Wire Connection	Voltage, V AC	Ht.	Wd.	Dp.	Housing Material		Each
10% to 100%	±1%	158	1 9/64"	2 13/16"	2	1	Screw Terminal	120	1 11/32"	3"	2 3/8"	Plastic	39635K44	0000000

Sensors

Relative Humidity
Range	Accuracy	Max. Operating Temp., ° F	Wire Connection	Wire Lead Lg.	Cable Lg., ft.	Ht.	Wd.	Housing Material	Fasteners Included		Each
20% to 90%	±5%	122	Wire Leads	1/16"	4	2 3/8"	31/32"	Plastic	No	39635K33	000000

Humidistats


For Humidifiers and Dehumidifiers	For Humidifiers

Turn the dial to control humidity equipment.

For Humidifiers and Dehumidifiers—Humidistats for humidifiers and dehumidifiers mount to a surface-mount outlet box.

						Overall
	Voltage	Current	RH	Switch Designation	Color	Ht.	Wd.	Dp.	Mounting Location	Mounting Fasteners Included		Each
For Humidifiers



		24V AC to 30V AC	1 amp	10% to 75%	SPDT	White	3"	4 3/4"	1 3/4"	Duct, Wall	Yes	2123K18	000000


		For Humidifiers and Dehumidifiers



				120V AC/208V AC/240V AC	6 amp/3.5 amp/3 amp	0% to 70%	SPDT	Beige	4 3/4"	3"	3"	Outlet Box	Yes	2123K14	000000

Enclosure Humidistats


Fixed Actuation Point	Adjustable Actuation Point

Reduce the humidity in your enclosure to prevent condensation that can cause corrosion and short circuits. These humidistats switch your heater on when the enclosure reaches the relative humidity setting. Once the humidity falls by 5%, the heater switches off. To install, clip humidistats to a DIN rail.

CSA Certified, CSA-US Certified, CE Marked, and VDE Certified, these humidistats meet American, Canadian, and European safety standards. They also meet UL 94 V-0, so if they catch fire, they self-extinguish within 10 seconds and won’t spread the fire by dripping.

Fixed Actuation Point—Fixed humidistats work for most applications. They keep humidity below 65%, which is when condensation is most likely to form. Since they aren’t adjustable, the humidity setting can’t be tampered with or accidentally changed.

Adjustable Actuation Point—For critical components, use adjustable humidistats to set the relative humidity you need in your enclosure. Use a lower humidity setting in damp environments and places with frequent temperature changes. Condensation is more likely in these situations.

	RH							Overall
	Setting	Difference	Tolerance	Voltage	Current	For DIN Rail Ht., mm	Switch Designation	Ht.	Wd.	Dp.	Enclosure Rating	Certification	Flammability Rating	Mounting Location		Each
Fixed



		65%	5%	-1% to 1%	120V AC	16 amp	35	SPDT	2 1/2"	1 5/8"	1 1/2"	IP20	CE Marked, VDE Certified, CSA Certified, CSA-US Certified	UL 94 V-0	DIN Rail, Enclosure	3869N14	000000


		65%	5%	-1% to 1%	240V AC	16 amp	35	SPDT	2 1/2"	1 5/8"	1 1/2"	IP20	CE Marked, VDE Certified, CSA Certified, CSA-US Certified	UL 94 V-0	DIN Rail, Enclosure	3869N13	00000


		Adjustable



				40% to 90%	5%	-1% to 1%	120V AC	16 amp	35	SPDT	2 1/2"	1 5/8"	1 1/2"	IP20	CE Marked, VDE Certified, CSA Certified, CSA-US Certified	UL 94 V-0	DIN Rail, Enclosure	3869N12	00000


				40% to 90%	5%	-1% to 1%	240V AC	16 amp	35	SPDT	2 1/2"	1 5/8"	1 1/2"	IP20	CE Marked, VDE Certified, CSA Certified, CSA-US Certified	UL 94 V-0	DIN Rail, Enclosure	3869N11	00000

Office Humidifiers

1.5 gal/day

Add fine moisture to the air. Fill the reservoir with water as necessary to reach daily output.

			Overall
Output Capacity	For Area	Reservoir Cap., gal.	Ht.	Wd.	Dp.	Housing Material	Electrical Connection Type	Voltage, V AC	Current, amp	No. of Blades	Cord Lg., ft.		Each
1.5 gal/day	3,000 cu. in.	0.75	9 1/8"	11 3/4"	6 3/8"	Plastic	Plug In	120	2	2	6	5489N11	000000

Dehumidifiers for Enclosures

Keep sensitive equipment dry inside enclosures. Also known as Peltier dehumidifiers, these dehumidifiers use electrical currents to remove moisture from the air. They’re smaller and require less maintenance than traditional dehumidifiers, since they don’t use refrigerant or compressors. However, they use more energy. Place dehumidifiers at the bottom of an enclosure, or mount them onto the included DIN rail. Moisture collects in the drain hose. Use a drain kit (sold separately) to direct moisture out of the enclosure.

Removal Capacity—Removal capacity is based on 80° F and 60% relative humidity.

	Overall								Drain Hose
Removal Cap., fl oz/day	Ht.	Wd.	Dp.	Housing Material	No. of Speeds	Electrical Connection Type	Voltage, V DC	Current, amp	Included	Lg., ft.	Temp. Range, ° F	Certification	Mounting Hardware Included	Includes		Each



	8	6"	5 1/2"	5 3/4"	Plastic	1	Hardwire	24	4.5	Yes	4	32 to 212	UL Listed, C-UL Listed, CE Marked	Yes	DIN Rail Mount	5654N11	000000000

Drain Kits

For Hole Dia.	Lg.	Material	Enclosure Rating	Certification		Each
7/8"	2"	Plastic	NEMA 4X	UL Listed, C-UL Listed	5654N12	000000

Large-Space Office Humidifiers

With an output capacity that's six times the output of our standard office humidifiers, this humidifier adds cool moisture to the air in a larger area. Fill the reservoir with water as necessary to reach daily output.

			Overall
Output Capacity	For Area	Reservoir Cap., gal.	Ht.	Wd.	Dp.	Housing Material	Electrical Connection Type	Voltage, V AC	Current, amp	No. of Blades	Cord Lg., ft.	Certification		Each
12 gal/day	21,600 cu. ft.	3.5	20 1/2"	21 1/2"	14 1/2"	Plastic	Plug In	120	0.8	2	5	ETL Listed	2120K79	0000000

Accessories and Replacements for Humidifiers

		Each
Bacteria Treatment (32-fl. oz. Jug) — Cannot be sold Outside United States	2121K15	00000
Replacement Filter	2120K89	00000

Absorption-Indicating Desiccants

Know when it's time to reactivate these desiccants. Use to remove moisture from sealed containers during shipping and storage.

Bags

Bags turn from blue to pink after absorbing 8% of their weight.

These desiccants are best when relative humidity is at least 40%. The area covered is calculated at 77° F and 40% humidity.

The bags have a monitoring window to check for desiccant color change.

	Absorption Cap. Relative to Desiccant Wt.	Lg.	Wd.	Wt., oz.	Bag Material	Features	Pkg. Qty.		Pkg.
Silica Gel Desiccants



	6	30%	1 3/8"	7/8"	0.04	Tyvek	Monitoring Window	10	3492T11	00000


	6	30%	1 3/8"	7/8"	0.04	Tyvek	Monitoring Window	1,000	3492T33	000000
	18	30%	1 3/4"	1"	0.11	Tyvek	Monitoring Window	10	3492T12	0000
	18	30%	1 3/4"	1"	0.11	Tyvek	Monitoring Window	400	3492T34	00000
	36	30%	2 5/8"	1"	0.21	Tyvek	Monitoring Window	10	3492T13	0000
	36	30%	2 5/8"	1"	0.21	Tyvek	Monitoring Window	300	3492T35	00000
	85	30%	3 1/8"	1 1/2"	0.5	Tyvek	Monitoring Window	10	3492T15	00000
	85	30%	3 1/8"	1 1/2"	0.5	Tyvek	Monitoring Window	115	3492T37	00000

Dehumidifying Cabinets

Store and protect 3D printer filaments, optical equipment, and other sensitive material in a humidity-controlled environment. Also known as dry boxes and desiccator cabinets, these cabinets prevent moisture-sensitive 3D printer filaments, such as nylon, ABS, and polycarbonate, from becoming brittle, discolored, or broken. They also keep sensitive electrical and optical equipment, such as microscopes and lenses, free from mold and fungus. Their moisture-absorbing desiccants recharge automatically, so you don't have to remember to charge them yourself or worry about the humidity rising unintentionally.

Standard

Standard cabinets are sized to store small equipment, such as flasks and lenses, as well as small filament spools. The desiccants recharge every 20 minutes to keep relative humidity below 30%. Although you cannot set the humidity to a specific level, a humidity meter on the door lets you check the reading.

	Overall				Shelf							Electrical
	Ht.	Wd.	Dp.	Wt. Cap., lb.	Movement (No. of)	Wt. Cap., lb.	Ctr.-to-Ctr. Adjustments	Max. RH	Desiccant Material	Material	Window Material	Connection	No. of Blades	Cord Lg., ft.		Each
Assembled



		12 1/2"	13 1/2"	16 1/2"	80	Adjustable (2)	40	4"	30%	Silica Gel	Plastic	Plastic	Straight Blade	2	8	3457N11	0000000


		20 1/2"	13 1/2"	16 1/2"	120	Adjustable (3)	40	4"	30%	Silica Gel	Plastic	Plastic	Straight Blade	2	8	3457N12	00000000

With Filament Feed Ports


Filament Feed Ports	Filament Feed Ports

Designed with 3D printing in mind, cabinets with filament feed ports are large enough to hold up to four 12"-dia. filament spools. They also have four filament feed ports, so you can keep filament dry while still feeding a printer, ensuring the filament doesn't go bad in the middle of a longer job. These cabinets can lower relative humidity to less than 20%; set and monitor the level using the analog display.

	Overall			Shelf								Electrical
	Ht.	Wd.	Dp.	Movement (No. of)	Wt. Cap.	Ctr.-to-Ctr. Adjustments	Max. RH	Desiccant Material	For Filament Dia., mm	Material	Window Material	Connection	No. of Blades	Cord Lg., ft.	Features		Each
Assembled



		21 7/8"	15 3/4"	16"	Adjustable (1)	Not Rated	1"	20%	Aluminosilicate	1.75 to 4.76	Painted Steel	Glass	Straight Blade	2	6	Analog Humidity Control and Display	3457N14	0000000

Desiccants

Remove moisture from sealed containers during shipping and storage. The area covered is calculated at 77° F and 40% relative humidity.

Bags

	For Area, cu. in.	Absorption Cap. Relative to Desiccant Wt.	Lg.	Wd.	Wt., oz.	Bag Material	Pkg. Qty.		Pkg.
Anhydrous Calcium Sulfate Desiccants



		1,300	6%	1"	2 1/4"	0.11	Paper	25	2140K31	000000


		1,300	6%	1"	2 1/4"	0.11	Paper	750	2140K51	000000
		2,600	6%	1"	2 1/4"	0.21	Paper	750	2140K52	000000
		2,600	6%	1"	2 3/4"	0.21	Paper	25	2140K32	00000
		12,275	6%	4"	3 3/4"	1	Paper	25	2140K43	00000
		12,275	6%	4"	3 3/4"	1	Paper	200	2140K53	00000
		24,525	6%	4 3/4"	3 3/4"	2	Paper	20	2140K44	00000
		24,525	6%	4 3/4"	3 3/4"	2	Paper	400	2140K54	000000
		49,075	6%	6 1/4"	3 3/4"	4	Paper	10	2140K45	00000
		49,075	6%	6 1/4"	3 3/4"	4	Paper	200	2140K55	000000
		98,150	6%	6 1/4"	5 3/4"	8	Paper	5	2140K46	00000


		98,150	6%	6 1/4"	5 3/4"	8	Paper	100	2140K56	000000


		Clay Desiccants



				2	18%	1"	5/8"	0.01	Tyvek	400	2139K71	00000


				2	18%	1"	5/8"	0.01	Tyvek	2,500	2139K83	000000
				9	18%	1 1/2"	7/8"	0.04	Tyvek	250	2139K74	00000
				9	18%	1 1/2"	7/8"	0.04	Tyvek	1,500	2139K86	00000
				30	18%	2 1/4"	7/8"	0.11	Tyvek	125	2139K75	00000
				30	18%	2 1/4"	7/8"	0.11	Tyvek	1,000	2139K87	000000
				235	18%	3 1/8"	7/8"	0.21	Tyvek	50	2139K76	00000
				235	18%	3 1/8"	7/8"	0.21	Tyvek	500	2139K88	00000
				715	18%	2 7/8"	2 1/8"	0.58	Tyvek	75	2139K77	00000
				715	18%	2 7/8"	2 1/8"	0.58	Tyvek	550	2139K89	000000
				1,425	18%	4 1/2"	3"	1.16	Tyvek	50	2139K78	00000


				1,425	18%	4 1/2"	3"	1.16	Tyvek	300	2139K91	000000
				2,850	18%	4 1/2"	5"	2.33	Tyvek	25	2139K79	00000
				2,850	18%	4 1/2"	5"	2.33	Tyvek	150	2139K92	000000
				5,700	18%	6 1/4"	5"	4.66	Tyvek	100	2139K93	000000
				5,700	18%	7"	6"	4	Polyester Plastic	12	2139K23	00000
				11,425	18%	8 1/4"	4 1/2"	9.31	Tyvek	7	2139K82	00000
				11,425	18%	8 1/4"	4 1/2"	9.31	Tyvek	50	2139K94	000000
				22,850	18%	11"	4 1/2"	18.62	Tyvek	3	2139K96	00000
				22,850	18%	11"	4 1/2"	18.62	Tyvek	25	2139K95	000000


				Silica Gel Desiccants



						6	32%	1 3/8"	3/4"	0.04	Tyvek	10	2189K14	0000


						6	32%	1 3/8"	3/4"	0.04	Tyvek	1,000	2189K34	00000
						24	32%	1 3/4"	1"	0.11	Tyvek	10	2189K15	0000
						24	32%	1 3/4"	1"	0.11	Tyvek	400	2189K35	00000
						235	32%	2 3/4"	1"	0.21	Tyvek	10	2189K16	0000
						235	32%	2 3/4"	1"	0.21	Tyvek	250	2189K46	00000
						1,425	32%	6"	1 1/2"	1	Tyvek	5	2189K17	0000
1,425						32%	6"	1 1/2"	1	Tyvek	300	2189K37	000000
2,850	32%					6"	5"	2	Tyvek	5	2189K18	00000
2,850	32%					6"	5"	2	Tyvek	150	2189K38	000000
5,700	32%					7 1/8"	5"	4	Tyvek	2	2189K19	00000


5,700	32%					7 1/8"	5"	4	Tyvek	100	2189K39	000000
11,425	32%					8 1/2"	5"	8	Tyvek	2	2189K21	00000
11,425	32%					8 1/2"	5"	8	Tyvek	50	2189K41	000000
22,850	32%					9 1/4"	7 1/2"	16	Tyvek	1	2189K47	00000
22,850	32%					9 1/4"	7 1/2"	16	Tyvek	30	2189K48	000000

Bulk


Bag	Pail

Reactivate these desiccants after use by heating them.

					Reactivation
	For Area, cu. in.	Absorption Cap. Relative to Desiccant Wt.	Wt., lb.	Container Type	Method	Temp., ° F	Time, hr.		Each
Silica Gel Desiccants



		691,025	33%	30	Pail	Oven	255	12	2181K101	0000000


		1,266,880	33%	55	Bag	Oven	255	12	2181K102	000000

Desiccants for Food and Beverage

FDA compliant for direct contact with food, these Tyvek bags absorb vapors, odors, and gases to keep products fresh.

Bags

	Absorption Cap. Relative to Desiccant Wt.	Lg.	Wd.	Wt., oz.	Bag Material	Food Industry Std.	Pkg. Qty.		Pkg.
Silica Gel Desiccants



	6	38%	1 1/2"	7/8"	0.03	Tyvek	FDA Compliant 21 CFR 172.230, FDA Compliant 21 CFR 172.480, FDA Compliant 21 CFR 175.390, FDA Compliant 21 CFR 177.1520, FDA Compliant 21 CFR 178.2010, FDA Compliant 21 CFR 182.90	1,000	5321N11	000000


	45	38%	2 7/8"	1"	0.17	Tyvek	FDA Compliant 21 CFR 172.230, FDA Compliant 21 CFR 172.480, FDA Compliant 21 CFR 175.390, FDA Compliant 21 CFR 177.1520, FDA Compliant 21 CFR 178.2010, FDA Compliant 21 CFR 182.90	300	5321N12	00000
	—	38%	3 1/2"	1 3/8"	0.35	Tyvek	FDA Compliant 21 CFR 172.230, FDA Compliant 21 CFR 172.480, FDA Compliant 21 CFR 175.390, FDA Compliant 21 CFR 177.1520, FDA Compliant 21 CFR 178.2010, FDA Compliant 21 CFR 182.90	150	5321N13	00000

Duct-Mount Humidifiers

Attach to your forced-air system return duct or mount through a wall to release humidity directly into a room. This humidifier spins water at high speeds to produce a fine atomized mist that rapidly evaporates.

		Overall		For Water Supply Line Tubing
Output Capacity	For Area	Dia.	Ht.	Size	Material	Drain Tube ID	Housing Material	Electrical Connection Type	Voltage, V AC	Current, amp	Mounting Hardware Included		Each
6 gal/day	7,000 cu. ft.	10 1/2"	12"	1/4"	Copper	1/2"	Plastic	Hardwire	120	0.4	Yes	2165K14	0000000

Wall-Mount Humidifiers

Connect these humidifiers to a water supply, and an electrical heater boils water to create steam. A built-in blower distributes humidity directly into a room.

Requires a humidistat (not included).

		Overall			For Water Supply Line Tubing		Housing
Output Capacity	For Area	Ht.	Wd.	Dp.	Size	Material	Material	Color	Electrical Connection Type	Current, amp	Certification		Each
11.5 gal/day @ 120V AC 23 gal/day @ 208V AC to 240V AC	16,000 cu. ft. @ 120V AC 32,000 cu. ft. @ 208V AC to 240V AC	21 3/8"	11 3/8"	6 7/8"	1/4"	Copper	Plastic	Gray, White	Hardwire	12.7	UL Listed	2170K21	000000000

Accessories and Replacements for Humidifiers

		Each
Required Humidistat	2123K14	0000000
Replacement Residue Collector	2170K51	000000

Rechargeable Small-Space Dehumidifiers

Place these dehumidifiers in small spaces to protect moisture-sensitive materials such as photo lenses or 3D printing filaments. They absorb moisture with a silica gel that changes color, letting you know when they’re saturated. While they don’t need a battery or power cord during use, you do plug them in to dry them out—unlike other desiccants, they don’t require an oven.

							Reactivation			Electrical
	For Area, cu. ft.	Absorption Cap. Relative to Desiccant Wt.	Lg.	Wd.	Dp.	Wt., oz.	Method	Time, hr.	Housing Material	Connection	No. of Blades		Each
Silica Gel Desiccant



		333	25%	6 1/4"	4 3/4"	1 1/4"	24	Plug In	12	Plastic	Straight Blade	2	3410N2	000000


		500	22%	8"	5 1/2"	2 1/2"	35	Plug In	15	Plastic	Straight Blade	2	3410N3	00000

Small-Space Office Dehumidifiers

Warm the air in small rooms to reduce humidity.

						Electrical
For Area, cu. ft.	Overall Wd.	Housing Material	Electrical Connection Type	Voltage, V AC	Current, amp	Connection	No. of Blades	Cord Lg., ft.	Certification	Mounting Hardware Included		Each



	95	18"	Aluminum	Plug In	120	0.1	Straight Blade	2	10	UL Listed	Yes	8226K18	000000


	130	24"	Aluminum	Plug In	120	0.1	Straight Blade	2	10	UL Listed	Yes	8226K22	00000
	190	36"	Aluminum	Plug In	120	0.2	Straight Blade	2	10	UL Listed	Yes	8226K25	00000
	320	48"	Aluminum	Plug In	120	0.3	Straight Blade	2	10	UL Listed	Yes	8226K27	00000