Thanks for the response GreenDesigns, I guess I'll keep looking.

They have one of these (a Best - Cirrus) installed at the Purcell-Murray demo kitchen in Brisbane, CA (as of Aug, 2012). It's over a new Thermador Freedom induction cooktop. I was shocked at how well it worked for being so high above the surface. Not too noisy either. Though I think the rep said there was a replacement part it needed that would quiet it down some more.

I think if you get it with an external blower you can size up the duct to 8".

We've looked at them too and wondered how efficient they are. DH thought it was great. I can't figure out why the unit is framed in black metal rather than white - I haven't seen too many kitchens with black ceilings.

Even with a duct large enough for a 1500 cfm external fan, which would preferably be 10-inch diameter, this unit is too small for the height it will be at, even for 7 ft ceilings. Much of the rising effluent would miss immediate capture, and likely would diffuse throughout the house before being cleared by the replacement air. In the meantime, some grease and moisture would collect on the ceilings, walls, and fabrics.

A foot or more of pan overlap would be needed for that height, leading to a hood that might be described as commercial sized. It would, though, not block sight-lines. Of possible interest is that the higher the hood, the more susceptible the rising effluent is to cross drafts and turbulence from people moving about, so the opportunities for escaping immediate capture are more frequent.

kas

I should add that a 3 x 1 or 2 x 2 array of these Cirrus units (depending on ceiling height) might be adequate, so long as the filters are cleaned often. Such a set would be very unobtrusive, and somewhat emulate the commercial perforated ceiling systems, though without their UV systems to break down the grease.

kas

> I can't figure out why the unit is framed in black metal rather than white - I haven't seen too many kitchens with black ceilings.

It's not black trim, that's the recessed portion of the vent which just looks dark because it is in shadow. It's all stainless steel.

Looks good, but that is a very narrow plume being collected, with a much lower expansion angle than was observed and reported in calibrated tests performed by Finnish researchers. I think this test should be repeated searing meat at a higher temperature than what was used for vegetables in the video.

(One might conclude, however, that if one won't be doing any cooking more intense than the veggie cooking in the video, this device is large enough so long as the cooking is directly below it.)

In general, the standard for capture video is schleiren photography, which can show by the imaged index of refraction changes in the air where heat (and presumably effluent) is going at the hood.

kas

Edit: This post only makes sense in the context of a commercial post that preceded it that must have been defenestrated by the admins. The removed post related to a video at the suppliers web site.

This post was edited by kaseki on Tue, Apr 29, 14 at 12:13