Whole house humidifiers can be beneficial for adding moisture to dry indoor air during colder winter months. However, there are some potential downsides to be aware of when considering installing a whole house humidifier.
Page Contents
- 1 Potential Downsides of Whole House Humidifiers
- 2 Risk of Over-Humidification
- 3 Maintenance Requirements
- 4 Mineral Dust Problems
- 5 Potential for Mold and Bacteria Growth
- 6 Increased Energy Use
- 7 High Water Usage
- 8 Added HVAC System Strain
- 9 Installation and Equipment Costs
- 10 Risk of Leaks and Water Damage
- 11 Noise Output
- 12 Concerns About Indoor Air Quality
- 13 Summary of Whole House Humidifier Downsides
- 14 Weighing the Pros and Cons
- 15 Conclusion
Potential Downsides of Whole House Humidifiers
Here are some of the main downsides or risks to be aware of with whole house humidifiers:
- Over-humidification – Adding too much moisture to the indoor air can lead to condensation issues.
- Maintenance – Whole house humidifiers require regular cleaning and filter changes.
- Mineral dust – The humidification process can disperse white dust from minerals in the water.
- Mold and bacteria – Excess moisture can encourage mold, bacteria, and other biological contaminants.
- High energy use – Humidifiers require energy to operate, increasing utility bills.
- Water use – Frequent refilling and water use, especially with evaporative models.
Let’s explore each of these potential downsides in more detail:
Risk of Over-Humidification
One of the main risks with any humidifier is adding too much moisture to the indoor air. The ideal indoor humidity level for comfort and health is around 30-50%. If humidity rises above 50-60%, condensation can occur on cold surfaces leading to potential mold growth and moisture damage.
With a whole house humidifier connected to the HVAC system, it can be difficult to control the exact humidity levels in different parts of the home. Some rooms may become too humid while others are left too dry. Monitoring indoor humidity with hygrometers in multiple rooms can help avoid over-humidification.
Signs of Over-Humidification
- Condensation on windows and other surfaces
- Damp feeling in the air
- Peeling wallpaper
- Musty odors
- Slow drying of wet towels or laundry
Maintenance Requirements
All types of whole house humidifiers require some degree of regular maintenance. Lack of maintenance is one of the top causes of humidifiers underperforming or failing prematurely.
Filter Changes
The humidifier filter captures minerals from the water before it enters the system. Buildup of these minerals can clog the filter over time reducing humidification efficiency. Manufacturers typically recommend replacing filters every 1-2 months of use, or more frequently if you have hard water.
Cleaning the System
In addition to filter changes, the humidification system itself needs periodic deep cleaning. Calcium and mineral deposits along with biofilm buildup inside the equipment over time. This should be scrubbed clean to avoid impaired performance and the spread of minerals or microbes into the air.
Cleaning frequency depends on water hardness and how often the system runs. Cleaning 1-2 times per season is typical for most homeowners.
Cost of Maintenance
Between frequent filter replacements and periodic deep cleanings, maintenance can get costly over time. Replacement filters can range from $10-60 each depending on the model. Some dealers include an annual cleaning service for around $100-200. DIY cleanings require purchasing cleaning solutions.
Neglecting required maintenance results in a humidifier not operating as designed. It wastes energy while providing insufficient humidification.
Mineral Dust Problems
Tap water contains dissolved minerals like calcium and magnesium. As water evaporates into the air during humidification, these minerals are left behind as microscopic white dust that can circulate through your home.
At high concentrations, this mineral dust can settle on surfaces leaving a white powdery residue. Breathing in the dust particles may also cause respiratory irritation in some individuals.
Using demineralization cartridges, distilled water, or reverse osmosis water in the humidifier can help reduce mineral dust. But this adds to maintenance costs.
Amount of Mineral Dust Based on Water Hardness
| Water Hardness | Mineral Dust Amount |
|---|---|
| Soft: 0-60 ppm | Low |
| Moderately Hard: 61-120 ppm | Moderate |
| Hard: 121-180 ppm | High |
| Very Hard: >180 ppm | Very High |
Knowing your water hardness level can give an indication of how much mineral dust to expect from the humidifier. Very hard water requires the most minerals to be filtered out.
Potential for Mold and Bacteria Growth
Excessive indoor humidity provides ideal conditions for biological contaminants like mold, bacteria, viruses, and dust mites. These organisms thrive in damp, humid environments with enough surface moisture to grow.
Over-humidification above 60% relative humidity significantly increases the risks of microbial growth on building materials, HVAC systems, and furnishings. Some potential health effects include:
- Allergic reactions
- Asthma symptoms
- Respiratory infections
- Headaches
- Fatigue
Controlling humidity levels and cleaning humid areas are important to limit contamination when using any humidifier.
Ideal Humidity Range to Minimize Microbial Growth
| Humidity Level | Microbial Growth Risk |
|---|---|
| Below 30% RH | Low |
| 30-50% RH | Minimal |
| 50-60% RH | Moderate |
| Over 60% RH | High |
Target 30-50% relative humidity to balance comfort with minimizing microbial contamination risks.
Increased Energy Use
Humidifiers use electricity or natural gas to boil water and produce steam. This adds to home energy costs, especially in winter when the system may run frequently.
In colder climates, a whole house humidifier may increase annual energy bills by 2-6%. Having a humidistat to modulate runtimes can help improve efficiency. Installing a high-efficiency model also minimizes energy use.
Estimating Humidifier Energy Use
- Steam humidifiers use 0.8kW on average while running
- Flow-through humidifiers use 0.1-0.5kW depending on mist output
- Fan-powered humidifiers use even less energy around 50-100W
Multiply the power rating by estimated daily runtime to determine increased daily kilowatt-hours. Over a season this can add up to hundreds of dollars depending on local electricity rates.
High Water Usage
Evaporative humidifiers work by dispersing water into the air. This can use hundreds of gallons over a typical winter season. Other types also require frequent filling and draining.
High water use may increase municipal water bills. Environmentally-conscious homeowners may want to minimizes consumption. Installing a rain barrel to collect water for the humidifier can offset purchases from the local water supply.
Typical Water Usage Rates of Humidifiers
| Type | Water Usage Rate |
|---|---|
| Steam Vaporizer | 0-2 gallons per day |
| Evaporative | 3-8 gallons per day |
| Flow-Through | 1-2 gallons per day |
| Ultrasonic | 1 gallon per 2-3 days |
Evaporative humidifiers have the highest water usage, while ultrasonic and steam models are more conservative.
Added HVAC System Strain
Introducing a whole house humidifier into the existing HVAC system places additional resistance on the equipment. Fans have to work harder to push air through the humidifier and ductwork.
Over time, this extra workload can cause blowers and fans to wear out more quickly. The heat exchanger or AC evaporator coil may also accumulate mineral scale faster due to humidification. More frequent professional cleaning and replacement of HVAC components may be needed.
Making sure the system is properly sized to handle the addition of the humidifier can help minimize strain. Have an HVAC technician assess ductwork and airflow requirements.
Installation and Equipment Costs
The upfront cost to purchase and professionally install a whole house humidifier averages $500-1500 depending on the type, brand, and complexity of integrating it with your HVAC system.
Larger homes may require a more powerful (and more expensive) humidifier to properly condition the air. Cool mist humidifiers are generally cheaper than steam models.
There is also the potential for unforeseen costs if ductwork needs modifications to accommodate the humidifier. Any repairs or upgrades required during installation add cost.
Cost Comparison of Common Whole House Humidifier Types
| Type | Average Cost* |
|---|---|
| Flow-Through | $350-800 |
| Steam Vaporizer | $800-1500 |
| Evaporative | $500-1000 |
| Ultrasonic | $400-900 |
*Estimated installed cost, including equipment and professional labor.
Risk of Leaks and Water Damage
Having gallons of water circulating through equipment in your home always presents some risk of leaks developing. Faulty float valves, overflowing reservoirs, cracked evap chambers, and loose plumbing connections are all possible sources of water leaks and damage.
Shutoff valves that automatically stop water flow in the event of a leak can help minimize damage. Still, any leaks that do occur can be messy, inconvenient, and costly to repair.
Preventing Leaks
- Install a water leak sensor
- Choose a reliable, brand name humidifier
- Have a technician install using best practices
- Perform regular inspections for leaks
- Repair any drips immediately
- Replace seals/gaskets on schedule
Being proactive with maintenance and leak detection helps avoid major mishaps.
Noise Output
Some homeowners may find whole house humidifiers disruptively noisy. Types with fans and motors that run frequently tend to generate the most sound.
Noises that can be heard throughout the home include:
- Humming
- Buzzing
- Rushing water
- Steam hissing
Careful installation away from living spaces and selecting quieter models can reduce noise. But it may still be audible during the quiet of night.
Quietest Humidifier Types
- Ultrasonic
- Evaporative wick
- Flow-through
- Steam vaporizer
- Evaporative drum/disc
In general, ultrasonic and wick humidifiers make the least noise. Steam types tend to be the loudest.
Concerns About Indoor Air Quality
Some people may hesitate to install a whole house humidifier due to concerns over potential negative impacts on indoor air quality.
Properly maintained humidifiers using clean water should not significantly degrade air quality. But issues can occur if over-humidification and microbial growth happen or minerals/sediments enter the air.
Using high quality water, controlling humidity, and practicing good maintenance helps ensure air quality stays safe. Consider having a professional air duct cleaning after the first season of use.
Summary of Whole House Humidifier Downsides
To recap, the main potential downsides and disadvantages of whole house humidifiers include:
- Over-humidification risks
- Frequent maintenance requirements
- Mineral dust residues
- Mold and bacteria growth
- Higher energy bills
- High water usage
- Added strain on HVAC systems
- Upfront installation costs
- Potential for leaks and water damage
- Noise output
- Concerns about air quality
Weighing the Pros and Cons
Humidifiers can provide comfort and health benefits during the dry winter season. But the potential drawbacks should also be carefully weighed before installing a whole home system.
Careful humidity monitoring, maintenance, and using high-quality models can help maximize benefits and minimize risks. Work with knowledgeable HVAC contractors to ensure proper sizing, placement and installation.
For moderate humidity needs, smaller room units may be a simpler option to avoid some downsides of central humidification. But whole house systems offer comfort and convenience when properly maintained.
Conclusion
While whole house humidifiers offer beneficial humidification, they also come with maintenance needs, operating costs, and risks like over-humidification and mineral dust. Weighing the pros and cons for your climate, home, and budget allows making an informed decision. With careful humidity management and maintenance, the benefits of whole home humidification can be enjoyed while minimizing downsides.