If he bumps his head at 30", won't he be bumping his nose on it at 24"?!
I mounted my island hood at 36" above my gas range, while it may not be optimal, it works just fine, and I don't bump my head, and have a clear view below it.

Interesting...we are a tall family and we have no problems with bumping our heads on our hood. It's mounted 30" above the cooking surface and is 24" deep - and none of us bump our heads. (I'm the shortest at 5'10" and my DS is the tallest at 6'6".)

Hmmm....I wonder if it's b/c it's glass. Our hood is SS. It could be that b/c it's glass it isn't "felt" as much. In our case, I think we have an "awareness" of the hood at all times and that's why we don't bump into it. The glass may be short-circuiting that "awareness" for your DH. (Glass is clear/SS is solid)

How strong is the fan? If it's over 1,000 cfms, you might be able to get away with mounting it higher. Is it at least 42" wide and 24" deep (the minimum recommended for a 36" cooktop/range when it's on an island or peninsula)? If you have stronger cfms (>1,000) and a properly sized hood, then I suggest you try mounting it higher. If you don't have size/fan strength, then you could replace it with a stronger hood/bigger hood.

If the hood is only 36" wide and/or the cfms are weaker, then the problem with mounting your existing hood higher is that you don't have a back wall or cabinets on the sides to help with containment. Add to that the fact that peninsulas & islands are exposed to more and stronger air currents, and I don't recommend raising it.

Perhaps your DH will get used to it over time?

I think the recommendation to lower it stems from the idea that if it's lower, your DH will be more aware of it and less likely to bump into it. Whether that would work or not, I don't know. If the hood is glass, why can't you see the back burners - you should be able to look through the glass... Not optimal, but it might be better than head bumping.

You're also running into another of the problems with island/peninsula cooktops/ranges - the hood is major presence in the kitchen and can obstruct views, etc.

I guess the picture did not upload, hopefully it does this time. I think one of the problems is that the glass is arched like wings instead of straight across. You are right ctyctm -- he will bump his nose and then myself at 5'4" will start having a problem (and who's more important?! LOL!). Buehl, we called the manufacturer who is the one who suggested that it be hung between 24 and 30" on an 8' ceiling above an electric range. It already looks obtrusive considering there was never anything there originally because we used a Jennair downdraft range. It is only 600 cfm so it may not be very efficient if we hang it higher. Plus it is as high as it will go without having to make a larger hole in the ceiling and shifting the entire square structure up into the ceiling - it is the only way to raise it which means reconstructing the entire support system in the attic. Which means a ton of work. Since it is Christmas, we'll hang a tree ornament from the corner to remind us until we get used to it. I think the huge bump on DH's forehead will keep reminding him to pay attention. Thanks for your comments!