Re: Daikin MC707/Siesta 7FS Air Purifier

A Reader writes:

Hi Ed,

I was wondering if you have come across the Daikin MC707 air purifier.

I cannot find any independent tests or reviews for this product.

It appears to use some unique technologies to purify the air, which also makes independent tests all the more important.

What are your thoughts on the product and manufacturer?

Any information will be helpful and much appreciated.

Thanks in advance,

Ed's Reply

Hey Reader;

Daikin's MC707 is an innovative high technology air purifier from a global Japanese corporation. But it has achieved minor market penetration only in the UK, which I assume is your location.

You are correct, I could find no user reviews or non-sponsored tests of the Daikin air cleaner.

Also marketed as the Siesta 7FS, MC707 uses an electrostatic ion stream to excite the surface of a photocatalytic oxidizer.

The usual ultraviolet lamp, commonly used in photocats, is absent.

This is a modern, economical, quiet, stylish, energy efficient, portable, and automated air cleaner.

However, it appears not to match HEPA specifications for .3 micron particle removal. Photocats will destroy .1 micron sizes, and filters trap 1 micron easily, which gives a lower efficiency for the elusive mid-size.

Daikin's Flash Streamer plasma ionizer positively charges dust and pollen particles, which are captured by the negatively charged Electrostatic Dust Filter.

This electrostatic setup is not new, but integrating it with a photocat is very clever.

Oxidation takes place within the MC707, not out in the room as with several competing Asian oxidizers, a safety plus.

Daikin's pleated electrostatic filter is not HEPA, in fact it is dispensed from a roll, torn off like a household paper towel.

The company's own sponsored testing shows only 82% efficiency on .3 micron particles, not 99.97% as required by HEPA specs.

However, this figure is for the air cleaner as a whole, and is not too bad compared to many true-HEPA installations.

High efficiency claims are supported only for larger particulate: "Allergen Removal 99.6%"

Electrostatic air cleaners typically experience efficiency decline with age, but the photocat helps keep coating and filter loading down - clever design.

A negative ionizer complements the setup, which emits acceptably low ozone.

The company claims no "waste" is generated, with 95% single-pass efficiency on formaldehyde. I am not sure this claim is adequately supported.

Formaldehyde oxidizes to acetaldehyde, complete oxidation seems unlikely.

But note that competing oxidizers - UV photocats, Plasmaclusters, and ozone - also have this problem.

Daikin Industries is a very large Japanese corporation with a long-established global air conditioner business. The Daikin MC707 air cleaner is warranted for a reasonable 3 years.

I'd hesitate to buy this in the USA, and support in UK seems limited to just a couple online dealers.

You'd be taking a chance on a clever high-tech product, nicely packaged.

But hey, I'm sure readers - I do have some in the UK - would appreciate your report of results.

Best wishes,

Ed