The truth about vaporisers and humidifiers
You’ve identified a need to increase your home’s humidity: what next? Walk into any department store or pharmacy and you’ll see a wide array of home health devices designed to do just that. But what’s the difference between them, and which one is the best for you? Read on to de ’mist’ ify your options…
Fact: Stream Vaporisers and Humidifiers BOTH humidify
Humidifying devices fall into two main groups: those which use cool mist to ‘humidify’ and those which use warm steam (in Australia, they’re called warm steam vaporisers).
Browse through any parenting forum or health website and you’ll find a lot of conflicting information. One of the most common misconceptions is that “humidifiers are for adding humidity” to a room and vaporisers are “just for colds and flu”.
The truth is they are both pretty much interchangeable: both types of device are designed to add moisture to the air. The difference is how they do this.
Cool Mist vs. Warm Steam – making the healthy choice
A cool ‘mist’ can be produced via several different methods (eg. ultrasonic, evaporative, impeller). What all cool mist humidifiers have in common is the lack of heat – and this is where they can be controversial. Without the benefit of heat, the “mist” that is distributed around the room may contain bacteria, mould or mineral deposits. These droplets are then inhaled, often by individuals who are already ill or in respiratory distress.
Ideally, distilled water should be used in cool mist units, but the drawbacks are that this can become expensive and inconvenient.
Steam vaporisers on the other hand produce steam by boiling water, which kills any bacteria or micro-organisms. Because the water is sanitized during the boiling process, a warm steam unit can use ordinary tap water.
Health authorities and research scientists in the field of humidity also sanction the use of warm steam vaporisers over cool mist units. This recommendation concluded a study published in the journal Environmental Health Perspectives:
“Humidification should preferably use evaporative or steam humidifiers, as cool mist humidifiers can disseminate aerosols contaminated with allergens.”1
Full steam ahead for easier breathing
Another big argument in favour of steam? Steam vapours are better designed for therapeutic benefit.
Steam is the gaseous form of water – as a gas it has the ability to blend with the air around it, thus staying longer in the air. Cool “mist” on the other hand is atomised water – water broken up into very tiny particles (between 1-5 microns in length). As droplets of water, they are suspended in the air for only a short amount of time, before gravity takes effect.
Think of when you spray an aerosol can into the air as compared to a manual pump spray. The gaseous aerosol output is suspended in the air for much longer, whereas the pump spray droplets quickly fall to the floor. For people relying on humidifier output to breathe in and out for therapeutic benefit this is a very important distinction… where would you rather your humidity, in your lungs or on the carpet?
Steam vaporisers have one final added benefit – inhalants. Steam vaporisers are designed to be used with inhalants, which are special medications - usually blends of natural essential oils - that have specific therapeutic benefits. (Added note: inhalants, unlike 100% pure oils, are designed to be disperse in water, so you can add them directly to the water inside of your vaporiser).
Inhalants can enhance the benefits of warm steam and help reduce congestion from colds, flu, croup, bronchitis and other upper respiratory illnesses. Other inhalants are designed to relax, soothe and unwind. Inhalants are exclusive to warm steam units as they rely on heat to ‘vaporise’ the essential oils, unlocking their therapeutic benefits.
1. Indirect health effects of relative humidity in indoor environments. Arundel et al, Environ Health Perspect. Mar 1986;65: 351-361.