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    HumidAire 3i™ Heated Humidifier

    HumidAire 3i™ Heated Humidifier

    The HumidAire 3i™ Heated Humidifier from ResMed is intended for use with S8 Series CPAP Machines. Those suffering from dryness and congestion may find relief in the warm air. The HumidAire 3i™ is no longer manufactured or sold by ResMed in the United States.

    Manufactured by ResMed.

    The HumidAire 3i™ Heated Humidifier from ResMed is intended for use with S8 Series CPAP Machines. Those suffering from dryness and congestion may find relief in the warm air. The HumidAire 3i™ is no longer manufactured or sold by ResMed in the United States.

    Product Features

    ResMed's HumidAire 3i™ Heated Humidifier directly connects to the S8 series CPAP Machine to transfer warm air from the water chamber to the user. Ease and efficiency were considered throughout the integrated design.


    • Easy to Use
    • Efficient Design

    Easy to Use

    The HumidAire 3i™ has a flip top lid, which allows the user to fill the water chamber without removing the tubing.

    The dial on the H3i™ allows the user to easily control their machine. With use of the dial, the user does not even need lights to correctly identify actions. The touch of the dial impacts the user by providing warm air from the water chamber to the mask. This warm air may help relieve problems with dryness, nose and mouth irritation, and even congestion.

    Efficient Design

    Intended for use with the ResMed S8 Series CPAP Machines, the H3i™ does not require additional outlets or power supplies. The integrated unit snaps together to create one piece, allowing the machine and the humidifier to operate on the same power supply. Being that the humidifier and machine connect to become one device, the footprint is minimal. In fact, the unit is both unobtrusive on the nightstand and easy to pack when traveling.

    The water chamber holds 385 mL of liquid, which is a significant volume. The more water the device can hold directly impacts the number of refills needed each time the machine and humidifier are used. With a higher volume, the customer may focus less on refilling their device each time it is used.


    This Product Includes...

    • Humidifier
    • Chamber
    • Carry Pouch
    • Cleaning Plug

    Product Specifications


    • Maximum Heater Plate Temperature: 185 deg F (85 deg C)
    • Temperature Cut-Out: 199 def F (93 def C)
    • Maximum Output Humidity: 95% relative humidity (control dial set to maximum setting, flow rate 50 L/min, ambient temperature of 68 def F (20 deg C), ambient relative humidity of 40%)


    • Chamber and Docking Station: 4.6" L x 6.7" W x 8.3" H (118 mm L x 164 mm W x 145 mm H)


    • Docking Station and Unfilled Water Chamber: 670 g (1.5 lb)

    Water Capacity

    • Maximum Fill Line: 385 mL

    Power Supply Input Range

    • 100-240V, 50/60Hz; 110V, 400Hz; 2.5A < 140 VA (110 W) (maximum power consumption).
    • Instantaneous peak power consumption <340 VA. Actual average power consumption will vary, depending on factors such as temperature setting, set pressure, the use of accessories, height above sea level and ambient temperature.
    • Maximum heater element power: 85 W

    Housing Construction

    • Docking Station: Flame retardant engineering thermoplastic, plated cast aluminum.
    • Water chamber: Injection molded plastic, stainless steel.

    Environmental Conditions

    • Operating Temperature: +41 deg F to +104 deg F
    • Operating Humidity: 10-95% non-condensing
    • Storage and Transport Temperature: -4 deg F to +140 deg F
    • Storage and Transport Humidity: 10-95% non-condensing

    IEC 60601-1 Classification

    • Class II (double insulation)
    • Type CF

    Electromagnetic Compatibility

    • Product complies with all applicable electromagnetic compatibility requirements (EMC) according to IEC60601-1-2, for residential commercial and light industry environments. *Consult the medical department of the carrier before using on aircraft. always offers these services:

    • 8 am to 10 pm CST Toll Free Phone and Email Support
    • 24 hour access to our Support Forum
    • Learning Center for information on sleep apnea and cpap equipment
    • Consumer Purchasing Trends Reports
    • Warranty Services for all items purchased through
    • Insurance Compliant Invoices
    • Free Prescription Request System

    Manufacturer Note

    • Some product images supplied by ResMed © ResMed 2010 Used with Permission.
    • ResMed products are for sale only to patients within the U.S. and not to other third parties or businesses.
    • A valid prescription is required for the purchase of this product.
    • All services provided by, including advertisement, ordering, sale, delivery, instruction, and setup of the products are performed solely by and independently of the manufacturer.

    Important Tips

    Power Tips

    This humidifier cannot be run off 12 volt power. If a machine is powered by 12 volts, the heated humidifier will not run. If a CPAP is powered by 110 or 220 volts it will power the heated humidifier. A 110 volt inverter hooked to a 12 volt battery can be used to power a machine and this humidifier.

    Compatibility Tips

    This humidifier integrates with the full ResMed S8 and S8 II lines of CPAP and APAP Machines. The H3i is not compatible with:

    • AirCurve 10 Series
    • AirSense 10 Series
    • S9 Series
    • S7 Series
    • VPAP III Series
    • VPAP Auto 25
    • VPAP ST
    • VPAP IV
    • VPAP Malibu

    CPAP Video & FAQ

    Frequently Asked Questions (FAQs)

    Are prescriptions required for mask, machine, humidifier, and Provent purchases?
    Yes. Federal law requires we have a valid prescription on file before we ship your mask, machine, humidifier, or Provent.

    We provide many easy ways to get your prescription:
    • We can request your prescription for you! When you checkout, just let us know you would like us to request your prescription, or you can log into your account to have us request your prescription.
    • Fax your prescription to our toll free fax number: 866.353.2727, or our international fax number: 713.541.7370
    • Email your prescription to
    • Upload your prescription in your account, under the Prescriptions Section
    • Ask your doctor to fill out our prescription form. We have both a standard prescription form and a Provent prescription form.
    For more information on prescriptions, please see our Prescription Section of the Learning Center.
    What is a heated humidifier?
    A heated humidifier uses heat to warm the water to add moisture to the airstream. The heat is adjustable for more or less moisture. A heated humidifier water chamber is much smaller than a passover humidifier water chamber.

    In our experience, it is common for CPAP users to report that their therapy is greatly enhanced by the use of a heated humidifier.

    There are three types of heated humidifiers:

    What is a passover humidifier?
    A passover humidifier uses a chamber of room temperature water with the CPAP to add moisture to the airflow and reduce irritation to the nasal passages.

    Air flows from the CPAP through a short hose to the humidifier chamber where the air "passes over" the water to pick up whatever moisture it can. The air then flows into the six foot hose to the mask.

    Passover humidifiers may provide sufficient moisture with CPAPs set at lower-end pressures. However, if the moisture is not sufficient there is no way to increase the amount of moisture added. The water is room temperature. In cold climates, the water temperature will drop causing the CPAP air to become very cold, and causing the amount of moisture to be reduced.
    What is an integrated humidifier?
    An integrated humidifier is used with a specific CPAP and fits directly onto the machine. For most heated humidifiers, this design eliminates the need for a second hose as well as a second power cord.

    An advantage of an integrated humidifier is that it works very closely with the CPAP machine to deliver humidification. Also, an integrated humidifier is a compact unit that uses fewer parts to provide moisture to the user.

    A disadvantage of the integrated humidifier is the user will receive less moisture when it is used with a passover humidifier. The smaller surface area effects the amount of moisture produced. Also, a integrated humidifier will only function with the CPAP for which it was designed.

    You can see if your machine has an integrated humidifier option by reviewing our Compare Charts.

    An example of an integrated humidifier is the PR System One Heated Humidifier as seen below attached to a machine in the PR System One line. PR System One Heated Humidifier

    Here are some of the integrated humidifiers we carry:

    DreamStation Heated Humidifier
    Transcend Heated Humidifier
    IntelliPAP 2 Heated Humidifier with Pulse Dose Humidification
    PR System One 60 Series Heated Tube Humidifier with Heated Tube
    What is a built in humidifier?
    A "built in" humidifier is designed as a part of the CPAP machine and cannot be removed or separated from the CPAP machine. As with an integrated humidifier, the design eliminates the need for a second hose or power cord. The water chamber can be removed for cleaning or replacement purposes.

    The advantage of a "built-in" humidifier is its compact shape, which operates on fewer parts. This integrated design helps to ensure optimum moisturized comfort and effectiveness when CPAP therapy and humidification are used together. Also, it allows an option for the humidification to be turned off while the CPAP is blowing.

    A disadvantage is that a built in humidifier may produce less moisture if used as passover because the surface area is typically smaller. Also, since the humidifier is "built in" to the machine, detaching it is not an option. This can be an issue for frequent travelers. Lastly, if the machine or humidifier stops working, the entire unit must be sent in for repair or replacement, not just the component that failed.

    An example of a machine with a built in humidifier is the ICON Auto CPAP Machine with Built In Heated Humidifier and SensAwake as seen below. ICON Auto CPAP Machine with Built In Heated Humidifier and SensAwake
    Here are some other machines we carry with built-in humidifiers:

    AirSense™ 10 CPAP Machine with HumidAir™ Heated Humidifier
    AirSense™ 10 AutoSet CPAP Machine with HumidAir™ Heated Humidifier
    iCH Auto CPAP Machine with PVA and Built-In Heated Humidifier
    + See More
    What is a stand alone humidifier?
    A stand alone humidifier is a component that will work with any CPAP and does not attach directly to the machine. It has its own power cord and a short hose to connect it to the CPAP. Generally it will sit next to the CPAP machine and is slightly larger than an integrated humidifier.

    The advantage of a stand alone humidifier is the fact that it may be used with any CPAP machine.

    The main disadvantages are that the size is often larger than either a "built in" or integrated humidifier and that a short hose is needed to connect it to the CPAP machine.

    An example of a stand alone humidifier is the Fisher & Paykel HC150 Heated Humidifier as seen below. HC150 Heated Humidifier
    What is rainout?
    Rainout is the accumulation of water in a CPAP tube due to warm moist air cooling and condensing on its way from your CPAP machine to your CPAP mask.

    The image below from Fisher & Paykel explains how rainout is formed. Warm, moist air leaves the heated humidifier and travels through the CPAP tube. As air flows through the tube, the temperature of the room causes the tube to cool. As the tube cools, the air inside releases its moisture, and creates condensation in the hose.

    Solutions to rainout include:
    • Raise the temperature of your bedroom.
    • Keep your CPAP machine at the same level as your bed.
    • Insulate your tubing with a hose cover like Snugglehose.
    • Reduce the tempurature setting on your heated humidifier.
    • Purchase a CPAP machine with a rainout reduction comfort feature.
    • Some machine systems offer a compatible heated CPAP hose which maintains the temperature from the machine all the way to the mask, reducing the occurrence of rainout. The list of available heated hoses can be found here: Hoses With Heating Coils.
    • If your machines uses a standard hose, consider the ComfortLine Heated Tubing Kit.

    Conventional Humidification
    How do I care for my humidifier?
    To care for your humidifier simply empty and clean the water tank each morning. Only distilled water should be used in the humidifier to avoid mineral deposit build up. S9 Dishwasher Safe Humidifier Chamber
    Here are some items that can help with caring for your humidifier:

    Control III Disinfectant CPAP Cleaning Solution - 16 oz Concentrate
    Control III Disinfectant CPAP Cleaning Solution - Home Care Kit
    Hurricane CPAP Equipment Dryer
    Why do I need to use distilled water with in my humidifier chamber?
    Use distilled water to help keep the humidifier chamber clean and mineral deposit free. Tap water should not be used as it will leave hard white mineral deposits in the chamber as the water evaporates, or it may lead to mold growth. Cases of lung disease have been connected to using contaminated well water in a CPAP humidifier.* Source

    If distilled water is not available where you live, use bottled water. It will be important to clean the chamber each morning, do not leave standing water in the chamber between uses.
    What does a humidifier prescription need to say?
    A humidifier prescription must contain all of the following information:
    • One of the following words or phrases: "CPAP Humidifier", "Humidifier", "HH", "CPAP Supplies", "CPAP Mask", "CPAP", "Continuous Positive Airway Pressure", "APAP", "AutoPAP", "AutoSet", "Auto CPAP", "Auto Adjusting CPAP", "Self Adjusting CPAP", "BiPAP", "BiLevel", "VPAP", "BiPAP Auto", "BiPAP ST", "Synchrony ST", "VPAP ST"
    • Your physician's contact information
    • Your physician's signature
    • The patient's full name

    Here are some of our top selling humidifiers:

    PR System One 60 Series Heated Tube Humidifier with Heated Tube
    Transcend Heated Humidifier
    XT Heated Humidifier
    + See More
    What are the CPAP, BiPAP and Sleep Apnea related HCPCS, CPT or billing codes?

    E1399 is Miscellaneous and is used for other CPAP items.
    Visit the Learning Center