Finding the Best Oil Diffuser
Want to scent your home or office? You type "aroma diffuser" or similar into your browser and wham! Instant overwhelm! What’s the difference? Why do some cost more? Are they safe for my family?
Many models look exactly the same, but on the inside, they are very different. Consider the photo below. The diffuser on the left is a nebulizing diffuser that emits pure essential oil. The other you fill with water. They couldn't be more different, but how would you know that by looking at them?
Left: An essential oil nebulizing diffuser. Right: An ultrasonic vapoizer that emits mostly water.
Most shopping sites don't offer much help. I did four searches on a well known site. I searched “water-free scent diffuser” and “waterless aroma diffuser” and “best scent diffuser” and "essential oil diffuser". All four searches returned the very same diffuser selection - only varying the order! And worse yet, every diffuser that appeared used water - even though I had typed "water free" and "waterless" in the search terms. I’m a diffuser expert! How would a non-professional know what they were seeing?!
Help is here! We’ve been building and providing diffusers to hotels, businesses, aquariums and even hospitals since 2005. So here's your quick expert guide for home and small office aroma diffusing:
Believe it or not, there are 6 common types of scent diffusers for home and office use. They are ultrasonic vaporizers (most common), reed diffusers, evaporators, fan diffusers, vacuum diffusers and nebulizing diffusers. Let's examine the benefits and drawbacks to each.
Left: Reed diffuser. Right: Evaporator style with heat plate and porous stones.
They type of diffuser most people are familiar with are reed diffusers or evaporators. Reeds work
by drawing up aroma oil where it evaporates into the air. Evaporators are the type where you put
a few drops of scented oil or essential oil onto a warmer plate They are
more effective if the plate has porous rocks or shells to help hold the
scent. Reeds and evaporators are great, silent diffusers for small spaces like bathrooms. Typically the scents that come with them
are synthetic – made from petroleum or chlorine based chemicals. However, if
healthy air is important to you, there are essential oil reed diffusers and evaporators. The
downside to reeds is that they can spill and
require flipping the reeds daily. Choose one with a wide stable
base. With evaporators, the scent needs to be refreshed regularly. The cost is as little as $20 to hundreds for a beautiful base.
Ultrasonic or Water Vapor Humidifiers
The ‘diffuser’ purchased most often is an ultrasonic style, which is actually a humidifier or water vaporizer. They use a
ceramic diaphragm that vibrates at an ultrasonic frequency to create
water particles that silently pour out as a ‘cool mist’. They are inexpensive - typically $20 to $50 - with a wide variety of attractive
designs. The downside? Water. What you see coming out of the machine is not scent, it’s water vapor. The vapor mist carries some scent
from the 10 or so drops of aroma you dripped into it. As such, there is little aromatherapy
But there is a more important safety issue! I can't even tell you how many people have said to me, "I bought one of these and now my family is having respiratory issues. What's up?" I'll tell you what's up! Mold! Consumer Reports did a test and found that every ultrasonic unit they tested - even those labeled as "anti-microbial" and "germ-free" - began growing and emitting mold into the air unless they were cleaned daily! So if you don’t have time for daily cleaning (like me!) or already have enough humidity in your air, avoid ultrasonic diffusers.
Remember! A few drops of essential oils in a vat of water will not be sufficient to kill mold! You would have to add 20 to 30% pure essential oil. The problem is water and oil don't mix, it may not mist properly, and it would be expensive. If you've ever seen how much water an ultrasonic uses, you'll know what I mean. The good news is there are other options.
Fan type diffusers - one with a pad that gets a few drops of scent (left) and one that uses a chemical scent cartridge (right)
Fan diffusers use batteries or AC to run a fan that blows air over a pad or gel aroma cartridge. They are very effective at putting out scent and the forced air expedites aroma delivery. Here are the drawbacks: First, fans use a lot of energy. Second, fans make constant noise. If you choose gel aroma cartridges, they are non-recyclable and derived of synthetic chemicals. For a 100% natural solution, you can get fan diffusers with a pad that you drip essential oils onto. However, they only scent small spaces. The fourth consideration is the most important. I find the scent level is almost impossible to regulate. When you first drip aroma onto the pad or put in a new aroma cartridge, the scent is strong. Each passing hour, its potency diminishes. Five, ten or twenty days later, who knows? Costs are usually $50 to as much as $300 for this type of diffuser. And refills can be expensive, i.e. 30-day gel cartridges can be as much as $80 each.
Vacuum style diffusers use an aquarium pump
Vacuum diffusers are the units you see with small glass
tubes inside a larger glass bulb. They may have a cover that hides the glass bulb
making it look more modern. Vacuum types are powered by an aquarium pump. It
vibrates a rubber bladder to create airflow that blows from one glass tube
across the top of the other. This creates a vacuum that pulls liquid scent or
essential oil up and emits it as small droplets of mist into the air. They
typically cost between $49 and $150. So what could go wrong? They're loud - you know the “aquarium” buzz. Be careful! The glass is fragile. The biggest issue: the tiny tubes clog, the rubber pump bladder stretches and scent stops coming out.
Nebulizing diffusers do not use water. They use a high powered pump to micronize the scent.
In my opinion, the best diffusers for the price are nebulizing diffusers. They work with a powerful pump that causes the liquid aroma to micronize into particles of 1 or 2 microns in size (about 50 to 100 times smaller than aerosol). The tiny particles go a long way and they don't float down and coat floors and furniture. Nebulizers can be small and affordable or super powerful. Some scent up to 2500 square feet! They don't use water - so no mold! 100% of the emitted aroma is pure scent. And every burst produces the same scent strength level from the first day to the bottom of the bottle.
They are ideal for pure essential oils, which are anti-bacterial, anti-fungal, anti-viral and anti-microbial. So you are actually cleaning bacteria, fungus, mold, microbes and many viruses from the air! Hospitals are saying that unlike synthetic anti-germ scent and disinfectants, essential oils are highly complex and effective at killing stubborn germs like MRSA!
Most nebulizing diffusers have programmable daily on and off
settings, as well as burst and rest periods. They can be easily adjusted for the
size of the space and cost only pennies per day to run. Set it and forget it until you refill. If it’s a good machine,
it will last for years.
Are there any downsides? Well, it depends on your point of view. They are usually a little more expensive. Prices range from as little as $69 to as much as $325 for all the bells and whistles. Once you have the scent in them, you must keep them upright or the liquid will pour out the top. Oh and I should mention, they make a little noise only when the scent is emitted - about the level of a whisper (15dB) on a good machine – a little louder on cheaper models. But that’s something to consider if you will use it when sleeping if you are a very light sleeper. It doesn’t bother most people, but consider that when locating it.
One important tip is to only use the essential oil and blends recommended by the manufacturer. Many blends will clog your diffuser and require service or void its warranty.
And one last thing, if you or anyone that will be in your
home or small office space has severe asthma or respiratory distress, be thoughtful about emitting aroma. Consult
your physician. With their input, perform a test with very small subtle amounts. If there is any discomfort, discontinue the process immediately. I
have clients with chemical sensitivities that claim the essential oil aromas
help them. Use proper common sense caution.
So there you have it! An insider's guide to understanding diffusers. I look forward to your questions and comments and hope this
information helps you find the best scent diffusion machine for you. Thanks for reading! Oh and be sure to check out my blog about eliminating smoke from your environment.