April 18, 2024

A whole-house humidifier connects to your home’s HVAC ductwork and cold air return. It can operate independently of or in conjunction with the HVAC system.

When activated, the humidifier collects water in a tray. Air flowing through the HVAC ductwork passes through this tray, picking up moisture. The air then cycles through the furnace and back into the ductwork, distributing the humidified air throughout the house.

Installing a whole-house humidifier can save you money and reduce energy usage. Higher humidity levels in your home allow you to lower your thermostat during winter, as humid air feels warmer. Depending on the type installed, whole-house humidifiers may also offer various health benefits.

Common Types of Whole-House Humidifiers

Bypass Humidifier

A bypass humidifier moistens warm air using a furnace. It draws warm air from the heating ducts and guides it through a water tray, where it gathers moisture before releasing it back into the house.

You can install a bypass humidifier on either the supply or return plenum of your central air system. However, bypass humidifiers usually require drainage for their water supply. If you lack a floor drain, you can opt for a drainless bypass humidifier, which recycles its water supply, reducing water usage.

Fan-Powered Humidifiers

Fan-powered humidifiers operate by using a fan to drive air through the water tray, promoting faster water evaporation. They can generate up to 1 gallon more humidity per day compared to bypass humidifiers. Additionally, they are more energy-efficient, as the internal fan consumes electricity equivalent to that of a 25-watt light bulb. Since fan-powered humidifiers are self-contained systems, they do not require a bypass duct, making them suitable for installation in smaller spaces. These humidifiers are particularly well-suited for homes built on slabs or with HVAC systems located in closets.

Steam Humidifiers

Steam humidifiers work by electrically boiling water to produce humidity in the form of steam. They circulate this steam throughout the ventilation system. Steam humidifiers are considered the fastest and most efficient method for increasing and maintaining optimal humidity levels in your home. Additionally, steam whole-house humidifiers offer the purest and most natural form of humidity available indoors. They can function independently of your HVAC system, ensuring consistent moisture levels throughout your home.

Why Does Indoor Air Get Dry During the Winter?

In winter, the cold air entering homes contains very little vapor because colder temperatures hinder the air’s ability to absorb moisture. Water molecules stick together due to vapor pressure, which is higher in warmer air than in cooler air, leading to higher humidity levels in warm weather.

Central heating systems can make winter air much too dry. Cold, dry outdoor air is drawn into the furnace. It is heated, and then it becomes even drier. This may seem contradictory to the idea of warmer air holding more water molecules, but heating outdoor air artificially reduces its relative humidity even further.

Relative humidity describes the amount of water vapor in the air relative to the maximum amount it can hold at a particular temperature. For example, at 0°C, air can hold only 4 grams of water per cubic meter, while at 20°C, it can hold 20 grams per meter. Thus, even if the relative humidity outside is 69% at 0°C, indoors at 20°C, it is only 18%.

The Health Impact of Dry Indoor Air During the Winter

Dry indoor air can adversely affect a person’s health in various ways. This is why the U.S. Environmental Protection Agency (EPA) recommends maintaining indoor air humidity between 30% and 50%.


Cold, dry air can worsen asthma symptoms. In low-humidity environments, the moisture needed to hydrate bronchial tubes evaporates quickly, leaving airways susceptible to irritation. Apart from asthma, conditions like bronchitis, sinusitis, and other respiratory illnesses can get worse in excessively dry indoor spaces.

Sore Throat

Many people wake up at night experiencing difficulty swallowing due to dry air causing inflammation and pain in the throat. Research indicates that lower humidity levels and cooler air temperatures lead to increased throat pain and irritation.

Eye Irritation

Dry air can disrupt the protective film on the cornea, leading to the formation of dry patches and making eyes vulnerable to other conditions.

Dermatitis and Dry Skin

Dry indoor air can worsen eczema symptoms and cause rough, dry skin, even in individuals without eczema. It may reduce skin elasticity and compromise the skin’s barrier, making skin more susceptible to damage from irritants or allergens. Dry air can also worsen existing dermatological issues like atopic dermatitis.


Nosebleeds are more common in areas with dry air, particularly during winter in heated offices or homes. However, they can occur in any season when indoor air humidity is too low.

Increased Stress

Prolonged exposure to very dry indoor environments may increase stress , as suggested by research examining heart rate and stress levels in buildings with varying air humidity levels. Studies indicate that individuals in drier environments exhibit a stress response in their heart rates and report experiencing less sleep.

Can Whole-House Humidifiers Improve Your Health?

Humidity is often ignored as a factor in indoor air quality and comfort. A lack of moisture can lead to nose and skin irritation and exacerbate illnesses. A whole-home humidifier connected to your heating and cooling system can help moisturize your nasal passages and improve breathing. Adding moisture to the air is important for health.

Whole-home humidifiers can minimize the risk of illnesses, as many bacteria and viruses do not do well in moist air. Since humidifiers add moisture to the respiratory system and nasal passages, they may help with snoring and might help a person get a better night’s sleep.

Most people find themselves adding moisturizer products to their skin during the winter. Their skin is itchy, dry, and cracking, with dull spots. Adding a moisturizer can help you keep your lips and skin smooth, avoid flakiness, and prevent the dryness usually associated with winter months.

Other Advantages of Installing a Whole-House Humidifier

In addition to health benefits, a whole-house humidifiers provide various advantages. For example, they offer consistent humidity levels, unlike portable humidifiers, which may only humidify one room effectively but cannot maintain consistent humidity throughout the entire house.

A whole-house humidifier also helps protect your home. Maintaining optimal humidity levels can safeguard wood furniture and flooring from damage. Adequate humidity prevents excessive dryness, which can cause warping or cracking of wood furniture.

Work With Certified HVAC Professionals in Shawnee, KS

At Air Care Heating & Cooling, we have been offering high-quality HVAC services to the residents of Shawnee, KS and the Kansas City area since 1981. We are proud of the team we’ve built. We are EPA and National Comfort Institute (NCI) certified. We proudly use Energy Star products and are members of the Air Conditioning Contractors of America (ACCA). We employ NATE-certified technicians who are experienced in repairing all makes and models of HVAC systems.

Our services include HVAC installation, maintenance, and repair. We install air purifiers, whole-house humidifiers, dehumidifiers, water heaters, tankless water heaters, and mini-splits. We work in both residential and commercial settings and offer geothermal heating and cooling systems as well as other HVAC products.

Contact Air Care Heating & Cooling today, and see for yourself what it is like to work with a team that cares about keeping you comfortable.

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