Drum Humidifiers

Drum Humidifiers: A Buyer’s Guide

Drum Humidifiers: A Buyer’s Guide

This article on drum humidifiers is part of a series examining the different types of whole house humidification systems.

Our main guide provides an overview of the key differences between all the major whole house options.

This specific guide will provide a buyer’s guide focused on drum humidifiers – how they work, pros and cons, maintenance tips, and recommendations.

Please check our other individual humidifier type articles to help determine the best whole home humidification solution for your needs.

How Drum Humidifiers Work

Drum humidifiers contain a drum or cylinder that holds replaceable evaporative filter pads or belts.

A motor rotates the drum to expose the pads or belts to the air flow. A fan then blows air through the moistened pads, releasing water vapor into the home’s ductwork to humidify the air.

Component Function
Rotating drum Holds evaporative media pads or belts
Evaporative media Absorb and release water vapor when air passes through
Fan Blows air through media to add moisture
Water supply Auto-filled from home’s water line
Humidistat Senses and controls humidity levels

Water is automatically refilled from the home’s supply line via a solenoid valve.

The humidistat senses humidity and activates the drum and fan to maintain the desired level.

Where You’re Most Likely to Find Drum Humidifiers

Drum humidifiers are more commonly used in commercial and industrial settings than in residential homes.

Some examples where drum units are typically installed:

  • Warehouses, manufacturing facilities, and fabrication shops where a rugged humidifier is needed. The drum design is durable in these environments.
  • Greenhouses, nurseries, and agricultural grow facilities that require supplemental humidity over large spaces.
  • Museums, archives, and art galleries, as the evaporative technology doesn’t over-humidify sensitive collections.
  • Commercial office spaces, schools, churches and theaters for cost-effective humidification.

When to Choose a Drum Humidifier

Drum humidifiers can make sense in these residential or commercial circumstances:

  • Humidifying large, open floor plan spaces. The drum units can effectively disperse moisture over an expansive area.
  • In spaces where regular maintenance access is possible. The frequent pad changes are easier with readily available access.
  • For supplemental, seasonal humidity rather than continuous year-round humidification.
  • When a humidifier needs to be mounted separate from existing ductwork. Drum units use exterior hoses.
  • Cost is a significant factor. Drum models are cheaper than most other types.
  • Easy installation is desired. Drum humidifiers require minimal duct modifications.

Benefits and Drawbacks

Drum humidifiers have some pros but also come with downsides:

Pros Cons
Don’t need duct integration Frequent pad replacement
Easier for DIY install Can breed mold/bacteria
Lower upfront cost <$500 Allow mineral buildup
Affordable replaceable parts Prone to leaks
Adjustable humidistat Noisier operation
Limited moisture output
Less precise control
More parts to replace
Shorter lifespan
Not for large homes

Maintenance Tips

Proper maintenance is crucial to extend the lifespan of a drum humidifier and avoid issues. Recommended maintenance includes:

  • Replace pads/belts – This is needed every 1-2 seasons, more often if micobial growth observed.
  • Clean fill valve – An annual flush and cleaning prevents valve clogs.
  • Clean fan/housing – Wipe down and remove dust/debris from fan and drum housing.
  • Flush supply lines – Periodically flush supply lines to reduce mineral buildup.
  • Check for leaks – Inspect around joints, seals, and drains. Repair leaks immediately.

Troubleshooting Problems

Some common drum humidifier problems and their causes:

Problem Cause
Pads drying out quickly Clogged fill valve not refilling
Mineral deposits/dust Hard water, lack of flushing
Water overflow Stuck fill valve or solenoid
Fluctuating humidity Dirty humidistat sensor
Fan not spinning Jammed drum, faulty motor

Replacement Parts

With periodic maintenance, drum humidifiers can operate for 5-10 years.

Eventually parts wear out and need replacement. Common replacement parts include:

  • Evaporative pads/belts
  • Water solenoid fill valves
  • Humidistat control boards
  • Fan motors
  • Drum motor and bearings
  • Cabinet housing<

    How to Clean a Drum Humidifier

    Regular cleaning and maintenance is key to extend the life of a drum humidifier. Follow this process to thoroughly clean your drum humidifier:

    1. Turn off power to the unit at the breaker.
    2. Remove the front cover of the drum housing.
    3. Carefully slide out the drum, removing it from the motor shaft.
    4. Remove old evaporative pads/belts and discard.
    5. Rinse and clean the drum cylinder thoroughly with a hose.
    6. Use a stiff brush to scrub out any mineral deposits.
    7. Rinse and wipe down the humidifier housing interior.
    8. Install new replacement pads or belts.
    9. Slide drum back into place and replace housing.
    10. Turn power back on and test operation.

    Key Takeaway

    If you need an affordable whole home humidification option and want to tackle installation as a DIY project, a drum humidifier may be a suitable choice.

    The ability to mount the drum units externally without duct integration provides more flexibility for installation. Just be prepared for frequent maintenance like changing evaporative pads and belts.

    However, for larger homes needing maximum moisture output or for those wanting a true set-and-forget solution, other types like steam, warm mist, or flow-through humidifiers would likely be better options.

    Though at a higher upfront investment, they provide higher capacity humidification and less long-term maintenance when properly installed.

    Carefully weigh the pros, cons, and your specific needs when choosing between drum humidifiers and other types.
    For moderate humidification needs on a budget, drum models can potentially get the job done.
    But they require more diligent care and have performance limitations compared to other available technologies.


Drum humidifiers can be an affordable DIY-friendly option.

However, weigh the pros and cons carefully.

Their high maintenance needs, potential for leaks, and limited moisture output make drum models less ideal for large, multi-room homes.

With proper care and part replacement, they can sufficiently provide supplemental humidity.

But other types like bypass and steam may be better long-term solutions.

Frequently Asked Questions

How often do drum humidifier pads need replacement?

Pads typically need replacement every 1-2 seasons, or more frequently if microbial growth is observed.

What causes leaks in drum humidifiers?

Leaks most often occur due to worn seals or improper installation. Checking for cracks and ensuring tight seals prevents leaks.

Do all drum humidifiers have a humidistat?

Most models have a built-in humidistat to control moisture output. Some basic units lack this feature.

How often should I clean the water supply valve?

Cleaning the fill valve annually is recommended to prevent sediment buildup and ensure proper water flow.

What causes mineral dust from a drum humidifier?

Mineral dust results from hard water not being properly filtered. Annual flushing and using distilled water can help.

How can I reduce noise from the drum humidifier?

Check for debris stuck in fan intake or drum. Lubricate motor bearings. Replace worn out fan motor if needed.

How do I check for leaks?

Inspect seals, gaskets, and drain connections for moisture and cracks annually. Leaks will require new seals or parts.

What is the lifespan of a drum humidifier?

With proper maintenance, a drum humidifier typically lasts 5-10 years before needing replacement.

How long do replacement belts last?

Evaporative belts need replacement every 1-2 humidifying seasons, or more frequently if heavy mineral buildup occurs.

What causes humidity fluctuations?

A dirty or malfunctioning humidistat sensor can lead to improper humidity control and fluctuations.

Published by

Dennis Reed

Dennis Reed Owner and Author @ BreatheBetterAir.org