About this site

The first thing to know

This site is published by Scentech V.O.F., a Dutch partnership at Buitenhaven 65, 5211 TR 's-Hertogenbosch, registered with the Netherlands Chamber of Commerce under number 95312048, VAT number NL867082719B01. Scentech makes and sells the Smart Aroma Diffuser, the Smart Aroma Diffuser 2 and the Smart Aroma Diffuser Pro, which are the first and second entries in our ranking and one further model referred to throughout. There is no agency between us and the products, because there is nothing between us and the products.

That is an unusual position from which to publish a comparison, so it is labelled at the top of every page and repeated in the footer: this is an advertisement feature. An order placed at getscentech.com after following a link here is attributed to this site, and the ranking is therefore not independent. We never describe it as such, and you should not read it as such.

Why we write about a kind of machine we do not make

Because the question in the search box is answerable and the honest answer is sometimes a product we do not sell. An essential oils diffuser, strictly speaking, is an ultrasonic machine: a tank of water dosed with drops of pure plant oil. Scentech does not make one. What we make is a pod machine that runs sealed 65 ml bottles of blended fragrance oil, takes no essential oils at all, and voids its own warranty if you try.

Both of those sentences appear in the lede, the verdict and the buying guide on the front page, because a guide that hid the second one would be worth nothing. Five of the seven machines we rank are ordinary essential oil diffusers that will happily take the bottle in your kitchen drawer. If that is what you want, the page will tell you which one to buy and why, and it will not try to talk you out of it.

Three rules we set ourselves

Every number comes from a manufacturer's specification table, a retailer's product page or a public review platform, and carries the date it was read. Every product in the ranking, ours included, gets at least two genuine drawbacks. And where a figure is missing - coverage, decibels, consumption per hour - the entry says so rather than filling the space with an adjective. There is a great deal of "not stated" on this site. That is what the listings say.

How the ranking is built

Seven weighted criteria, scored out of ten: stated coverage, unattended run time, cost per millilitre, noise, control, upkeep and the size of the public review base. The weights, the sources, the things we deliberately did not do and the update log are on How we compare. We ran no laboratory test and took no measurements; none of the competing machines was in the house. Where a competitor's page carries a customer review we quote it dated and attributed, including the critical ones.

Scentech prices appear in pounds because the shop converts a euro price at checkout. They move with the exchange rate, so each carries the month it was read rather than being presented as a fixed UK price list.

Corrections

If a price, a rating or a specification here has moved, or if you think we have misread a listing, write to support@scentech.store or use the contact page. Corrections are made and then recorded in the update log on the method page.