Can I Use Distilled Water Instead of Tap Water in My Humidifier?

Using distilled water in your humidifier instead of tap water can help prevent mineral deposits that can clog the humidifier. The purification process of distillation removes minerals like calcium and magnesium from the water, which are the main components of mineral deposits.

However, the decision depends on several factors. This comprehensive guide covers everything you need to know about using distilled water in humidifiers.

What is a Humidifier?

A humidifier is a device that increases humidity levels in a single room or an entire home. It works by dispersing a fine mist of water vapor into the air. Humidifiers are commonly used during dry, cold weather to prevent problems like static electricity, dry skin, sore throats and scratchy sinuses.

There are four main types of humidifiers:

• Warm mist humidifiers boil water to produce steam
• Cool mist humidifiers use a wick filter, impeller, or ultrasonic technology to produce mist
• Evaporative humidifiers use a fan to blow air through a wet wick filter
• Steam vaporizers use electricity to boil water and release steam

What is Distilled Water?

Distilled water is water that has been boiled and condensed to remove impurities, minerals, and contaminants. The distillation process works by:

1. Heating water to the boiling point which produces steam
2. Collecting and cooling the steam which condenses it back into liquid water
3. Collecting the distilled water which now contains 99.9% pure H20

This heating and condensing process removes all minerals, salts, metals, and other dissolved substances, leaving behind pure water. According to the CDC, distilled water contains simply hydrogen and oxygen molecules (H20).

Characteristics of Distilled Water

• Neutral pH around 7
• No minerals or contaminants
• Low total dissolved solids (TDS)
• No fluorine, chlorine, or other additives
• May have trace levels of sodium from storage containers

Pros of Using Distilled Water in Humidifiers

There are several potential benefits to using distilled water in humidifiers instead of tap water:

Prevents Mineral Buildup

The main advantage of distilled water is that it prevents mineral deposits and scale from accumulating inside the humidifier. Tap water contains mineral ions like calcium, magnesium, silica and bicarbonate. As the tap water evaporates, these minerals are left behind, forming scale and deposits on the surface of the humidifier.

Distilled water prevents this buildup because the minerals have been removed. With no minerals to deposit, the humidifier remains clean and free of sediment.

Extends Lifespan of Humidifier

By preventing mineral scale, distilled water can extend the lifespan of your humidifier. Scale buildup can clog the humidifier’s internal components and reduce performance. Over time, substantial deposits can lead to overheating and cause early failure.

Using pure distilled water minimizes deposits, keeping the humidifier working efficiently for longer.

Produces Clean, Pure Mist

Since distilled water has no dissolved impurities, the mist it produces is clean. Tap water can contain traces of minerals, chlorine, fluoride and other substances that get dispersed into the air when the water evaporates. This leaves behind white dust on surfaces.

The pure mist from distilled water humidifies the air without adding contaminants. It won’t leave any mineral residue or white dust behind.

Prevents Bacteria Growth

The low mineral content of distilled water inhibits the growth of microorganisms like bacteria, algae and fungi. Tap water can promote more microbial growth. Using distilled water keeps the tank cleaner and reduces the risk of mold, mildew or bacterial growth which could get dispersed into the air.

Recommended by Manufacturers

Most humidifier manufacturers recommend using distilled water to prevent mineral scale. The manuals for brands like Honeywell, Vicks, PureGuardian, Levoit and more all suggest distilled water.

For example, the Levoit blog says: “We recommend using filtered or distilled water in your Levoit humidifiers. The pure water prevents mineral buildup from tap water that could affect your humidifier’s performance over time.”

Cons of Using Distilled Water in Humidifiers

There are also some downsides to keep in mind when using distilled water:

More Expensive than Tap Water

Distilled water is more expensive than tap water. You’ll need to continually buy distilled water from stores to fill up your humidifier. The cost can add up over time compared to just using water from your sink.

Inconvenient to Purchase

Distilled water may not always be easy to find. While it’s available at most grocery stores and pharmacies, you’ll need to make frequent trips to buy new jugs when you run out at home. This can be inconvenient compared to just using tap water.

Lacks Minerals Found in Tap Water

While pure, distilled water lacks many of the natural minerals found in tap water like calcium, magnesium and zinc. Some people believe the minerals in tap water have health benefits when dispersed into the air.

However, the tiny amount of minerals emitted by humidifiers is unlikely to make a significant health difference.

Overkill for Some Humidifiers

For evaporative humidifiers, distilled water provides no real benefit. Evaporative models don’t produce fine mists, so mineral dust is not an issue. The wick filters are inexpensive and designed to be replaced frequently.

Using distilled water may be overkill unless you have an ultrasonic or impeller humidifier that produces fine mists.

When Should You Use Distilled Water?

Here are some guidelines for when to use distilled water in your humidifier:

Humidifier Type

Use distilled water in:

• Ultrasonic humidifiers
• Impeller or cool mist humidifiers
• Warm mist humidifiers

It’s not necessary in:

• Evaporative humidifiers
• Steam vaporizers

Water Quality

Use distilled water if your tap water has:

• High mineral content
• Visible sediment or cloudiness
• Bad taste or odor
• High chlorine levels

Tap water with less than 200 ppm total dissolved solids is likely fine to use.

Mineral Deposits

Switch to distilled water if you notice:

• Scale buildup inside the tank
• White dust around the humidifier
• Minerals in the mist coming out

These are signs you need to remove minerals from the water.

Manufacturer Recommendations

Look at the user manual and see what type of water is recommended. Most brands suggest using distilled water.

Other Tips for Humidifier Care

To get the most out of your humidifier, follow these maintenance tips:

Clean Regularly

Clean and disinfect your humidifier every 1-2 weeks following the manufacturer’s instructions. This prevents mold and bacteria growth.

Change Filters

Replace any filters at the recommended interval to remove sediment and minerals.

Use Water Treatment

Try demineralization cartridges or water softeners to remove minerals from tap water instead of distilled water.

Dry Out Between Uses

Allow the tank to dry out completely between uses to prevent microbial growth.

Monitor Humidity Levels

Use a hygrometer to maintain the optimal 40-50% humidity range.

Descale Buildup

Use white vinegar to dissolve any mineral scale that accumulates inside the humidifier.

Frequently Asked Questions

Can you mix distilled and tap water?

Yes, you can mix distilled and tap water in any ratio you like. Many people mix a 50/50 blend to reduce costs while still minimizing mineral deposits.

Does distilled water remove minerals from the air?

No, distilled water does not remove beneficial minerals from the air. It simply doesn’t add any excess minerals to the air that a humidifier produces.

Is distilled water safe for humidifiers?

Yes, distilled water is perfectly safe to use in humidifiers and is actually recommended by most manufacturers.

Can you use purified or filtered water?

Purified water works similarly to distilled water, but check that it has a low TDS. Not all filtered water removes minerals, so check the specifics.

Is demineralized water the same as distilled?

Demineralized water has had minerals removed, but not always by distillation. Distilled water is a type of demineralized water.

The Bottom Line

In most cases, using distilled water in ultrasonic and cool mist humidifiers is recommended to prevent mineral buildup. It produces clean, mineral-free mist and extends the lifespan of the humidifier.

However, distilled water is more expensive, inconvenient, and lacks healthy minerals. For evaporative models, it’s often not necessary. Consider your water quality, humidifier type, and manufacturer guidelines when deciding.

And remember to clean your humidifier regularly for the best performance! By following these tips, you can determine if distilled water is the right choice for your situation.