Shopping for a HVAC steam humidifier?
You’ve come to the right place.
A HVAC steam humidifier is a great solution for humidifying your entire home if you live in a dry or arid climate.
But they aren’t the least expensive option, and you need to make sure you purchase exactly the right sized unit or you can end up with condensation issues that can damage furniture and floors.
In this guide, we recommend several proven HVAC steam humidifiers for a variety of situations and provide a buying guide to help you match one to your needs.
NOTE: If you are looking for a different type of humidifier - for one room, for example - then check out our other buying guides on this site:
Our 3 Favorite HVAC Steam Humidifiers For a Home
What’s In This Buying Guide
This guide begins with a detailed review of some of the best HVAC steam humidifiers available on the market.
After the reviews, we look at the factors you should consider when selecting a whole-home HVAC steam humidifier. We also explain what an HVAC steam humidifier is and how it works.
Finally, we end the guide by answering several frequently asked questions related to whole-house steam humidifiers.
Table of Contents
Best HVAC Steam Humidifiers
Our top overall pick is a reliable whole house steam humidifier manufactured by Condair.
Condair is a leading brand in home systems and appliances.
Their products are dependable and long-lasting, and this humidifier is no exception.
This whole-house humidifier is packed with automation and modern features that make it an ideal choice for any large house.
This Condair HVAC humidifier offers a coverage area of 5000 sq. ft., which is enough to cover most medium to large-sized houses.
The unit attaches directly to the furnace or an HVAC system.
A precise humidity control solution maintains a constant humidity of 40-60% RH throughout your home.
Controllable via a remote and monitored via a mobile app, the humidifier also features automated water refilling.
All these features make this system convenient to operate. Furthermore, the humidifier works quietly, causing no disturbances.
Perfect for small houses ranging up to 1400 sq. ft. in size, this Emerson house humidifier is built on climate smart technology.
It is powered by 120V and features a humidistat and automatic controls that ensure a perfectly humid environment at all times.
The built-in humidistat detects any changes in optimal humidity indoors, then activates the furnace which boils the water to produce steam.
Using the fan control relay, you can control the speed at which the mist is introduced into your home.
The Emerson unit features a flushing timer that saves water during refill and mist generation.
The water filter prevents impurities, dust, and debris from polluting the steam, ensuring a safe breathing environment.
With a rated output of 13 gallons per day, this humidifier is our top choice for smaller homes. The price really good, too.
The Aprilaire 800Z 800 Whole Home Steam Humidifier Is a well-built unit with features that make it a good choice for any large home with unique needs. It is designed to maintain average relative humidity in the 35%-45% range.
The 800Z uses electrode technology to boil the water, which makes it more energy-efficient than most.
Another benefit of electrode heating is that the presence of impurities and minerals in the water increases its efficiency, so filtering the water for this humidifier is not required.
Featuring dual sensors, the Aprilaire 800Z HVAC humidifier responds to outdoor temperature to regulate interior humidity.
There are six levels of misting output ranging from 11.5 to 34.6 gallons of moisture per day that you can choose from. This makes it useful in a wide variety of climates and situations.
HVAC Steam Humidifier Buying Guide
Here are the important considerations you should take into account when selecting the best HVAC steam humidifier for your home:
Age and Build of Your House
The age of your house and its construction will impact the effectiveness of any HVAC steam humidifier.
If your house is more than 50 years old, it probably lacks proper house wrap and modern insulation technology. If that house has not been renovated in a while, there is a good chance that its doors and windows have drafts that can let air pass through them.
Houses less than 50 years old without proper and regular renovation are also considered to be loosely built. In such settings, the mist from the humidifier will be lost through uninsulated walls and drafty windows and doors.
Average build houses ~25 years of age often have a house wrap and upgraded windows and doors along with other renovations. They are better able to retain moisture indoors but are still subject to some losses.
Tighter-built houses less than 20 years old are usually equipped with much better insulation technologies and sealed windows. They are very good at retaining moisture from a humidifier indoors.
In short, a humidifier with the same coverage area and capacity will perform much worse in a loosely sealed house than in a tightly sealed house.
For example, a steam humidifier with a size rate of 4,000 sq. ft. might only cover 1,250 sq. ft. in loosely sealed home, 2,000 sq. ft. in average sealed home, and 4,000 sq. ft. in tightly sealed home.
Therefore, make sure that the room size rating of the humidifier is sufficient to match the needs of your building, age and construction.
The capacity of an HVAC humidifier determines its running cost.
A high-capacity unit will causes a noticeable spike in your electricity bill.
Look for more modern electrode-heated units to save on energy costs.
Depending upon the type of HVAC steam humidifier, it may only accept distilled water, purified water, filtered water, tap water, or all of these.
So you need to be realistic about the quality of water source available to supply the humidifier.
Further, if you are on a tight budget you should opt for a model that can use tap water; otherwise, you may have to spend extra money to purchase a reverse osmosis system to purify the tap water before it can be used. Otherwise, you’ll have to hand-fill the system which gets REALLY old, really quick.
What is a Humidifier HVAC Steam Humidifier and How Does it Work?
An HVAC steam humidifier is a type of house humidifier that uses heat to boil water. Water vapor is then distributed throughout the house to add moisture to the air to reduce dryness and improve breathability.
A HVAC steam humidifier connects directly to the HVAC system of your home. Heat generated by your HVAC or furnace system is used to boil the water in the humidifier. The mist formed is then distributed via the ducts of the system throughout the house.
HVAC steam humidifiers are known for their ability to maintain uniform distribution of humidity in a home, making the living atmosphere more comfortable and protecting hardwood floors and furnishings throughout your home. This is sharp in contrast with almost every other kind of portable or dedicated humidifier, which typically only add humidity to a single room.
Why Buy an HVAC Steam Humidifier?
A steam humidifiers are very efficient at humidifying dry areas because they leverage heat from your heating/furnace which is almost always being used at the same time.
Steam humidifier are also very simple units that will last for a very long time with proper maintenance.
Moreover, HVAC-attached humidifiers do not require additional duct work and most are supplied with water automatically, making them more convenient and hands-off than other types of humidifiers sold today.
What to Look for in a HVAC Steam Humidifier
Steam humidifiers are crucial in maintaining a livable atmosphere, especially in dry, low humidity areas.
But not all models will serve your needs.
Here are the most important features to consider when buying aHVAC steam humidifier for your home:
First and foremost, you should consider the capacity of the steam humidifier. Because these humidifiers are very efficient, you need to make sure to get the right capacity for the size of your home.
As discussed earlier, the sealing and age of the house or building play an important role in determining the performance of your humidifier.
Modern HVAC steam humidifiers are rated for new, tightly-built homes.
Larger, older, loosely-built houses will need about twice the humidifying capacity of a newer, smaller home.
A minimum capacity of 6000 sq. ft. is required to provide full coverage to a tightly-built modern home – or a loosely-built older home of up to 3,000 sqft.
A capacity of 3000 to 4000 sq. ft. will usually suffice for most modern homes.
Capacity of less than 3000 sq. ft. is only usable in small homes.
Final tip: make sure that the capacity does not exceed the probable needs of the building. If the air is over-humidified, condensation may occur which causes all sorts of problems with wood flooring & furniture, smooth surfaces, and windows.
Look for the following features to ensure that your HVAC steam humidifier can operate in a hands-free manner:
- a permanent water supply (to your water tap or filtered water source)
- a humidistat, to measure room humidity levels and control the unit
- a remote control, to let you control humidity manually
- an automatic mode, to let you set it and forget it
In addition, the following optional features will further simplify maintenance and cleaning:
- a built-in water filter, to prevent mineral buildup and reduce cleaning
The design and construction of a steam humidifier are as important as its performance.
A unit made with sturdy material is more reliable and would serve you longer than those made with cheaper low-quality materials.
The right mounting frame can greatly aid the installation process and ensure the unit isn’t damaged when running.
Furthermore, you want to avoid units made from or contained within materials that can corrode, rot, or become brittle over time.
Pros and Cons of Using a Steam Humidifier
Clean Water Vapors
Boiling water to form steam rids the resultant mist of most harmful microbes that might be present in the water. As a result, the clean mist is distributed throughout the house.
This is not the case with all types of humidifiers.
Humidifiers that use evaporative technology, for example, do not eliminate the danger of microbes and mold. However, steam humidifiers ensure a safe breathing and living atmosphere.
No Need to Refill
Steam humidifiers typically have a direct connection to a running water source. You won’t have to get up and refill the humidifier every time it runs out of water.
With other types of humidifiers, you often are on the hook for refilling a water bin once or several times per day.
Suitable for Whole Homes
Most humidifiers can only treat one room. To moisturize a whole house using them, you’d have to purchase several units – and manage and keep refilling them all. (don’t try)
In contrast, the large capacity and hands-free operation of HVAC steam humidifiers makes them usable for treating large spaces and whole houses.
Steam humidifiers are more expensive to buy, install, run, and maintain than other types of humidifiers.
Most require professional installation, too.
In addition, the high capacity consumes more electricity which adds to your electricity bill.
If neglected, maintenance could add up to a sizable amount as well.
Requires An Existing HVAC System
The performance and operation of an HVAC steam humidifier is completely dependent on the presence of an HVAC system.
Without an HVAC system that supplies enough heat to boil water, you cannot use the humidifier.
This requirement limits the use of HVAC steam humidifiers to buildings that have pre-installed systems.
Make sure you check the supported HVAC systems before purchasing a steam humidifier for it.
Cleaning and Maintenance of Steam Humidifiers
If steam humidifiers are not cleaned and maintained properly, they pose the risk of mold growth and loss of efficiency. Therefore, for optimal running and a safe environment, proper maintenance is crucial.
That said, these humidifiers do not demand deep-cleaning or expensive maintenance. All you have to do is make sure that the water intakes remain unclogged and the water canisters/filters are kept clean.
Gently scrub any mineral deposits away that might have appeared on the surface of the humidifier.
Under constant use, you should replace old canisters every year.
Make sure that the water supply to the humidifier is kept clean and free from mud and debris. We recommend using an in-line water filter system to do this job for you. Mount the filter in your HVAC utility closet, so you can easily replace filters.
Steam Humidifiers: Frequently Asked Questions
Is mold a problem with steam humidifiers?
No, steam humidifiers do not cause mold. They maintain precise levels of optimal humidity that will not promote growth of mold in the house. Furthermore, the steam is formed by boiling water, which kills any mold present in the water.
Are steam humidifiers expensive to run?
Steam humidifiers are not very expensive to run. They do require additional electricity to power the furnace or other heating elements; however, they also save on water costs.
In the end, the two costs balance each other out considerably.
How often does a steam humidifier need a refill?
HVAC steam humidifiers are typically connected directly to a water supply. When the water level is low, the supply automatically provides water to the humidifier. As a result, you don’t have to refill the humidifier yourself.
Final Verdict: What is the Best Steam Humidifier?
We believe the Aprilaire 800Z Whole House Steam Humidifier is the best overall choice for most homes. It’s designed for medium to large tightly-sealed houses and offers features that make it especially easy to customize for use in any sized home or climate.
I’m a degreed ME (mechanical engineer) who is passionate about machines of all kinds. I created MachineWonders.com as a way to connect with others who love machines like me – or need help choosing one for their needs, application, or situation.