Small bends will have very little effect. Even a 90 or two would not be a huge deal for 10" duct at 1200CFM, but avoid if you can. If you have a roof-mounted blower, things will get more quiet if you can move it further away from the hood. The adjustable elbows have sections to turn, and adjust anywhere from 0 to 90 degrees. Here is a link that might be useful: Duct elbow (adjustable)

Seriously I think the connection to BTU and ventilation exists, but you have to consider why. I had a friend last week ask me how she could sear a steak on her small burners... I told her to use her cast iron skillet and leave it on the burner until a drop of water bounces around on it. I told her not to crowd the pan, and why the steak would suck the heat out, and why cast iron would hold so much heat. She told me she took my advice and then some. While the steak was cooking on one side, she pre-heated a second cast iron skillet she had and when it was time to flip the steak, she flipped it into the other- by now 'hot' skillet. She said it came out perfect. You can imagine my despair in the old days when even at breakfast the alarm would go on if I cooked bacon and eggs (when I lived in rented apartments), even steam from pasta would set the frigging alarm off. Then I needed more water and a bigger pot to boil the water and at least twice the time, because the pasta would just take the water temp right down.. Now with a bigger BTU burner I don't need as much water because it comes back up to temp so much faster. Speed and control is what larger burners are about. You can certainly turn the burners down when you don't need the extra power. Having decent pans will go a long way, the extra power only adds speed and might change what you like to cook. A lot of people on this forum will tell you how important ventilation is when you buy that deluxe fancy range. The fact is, yes, if you are cooking for a big party and food is flying, grease is frying, steam is rising and ovens are roaring, you will need what ever you can get. I can't tell you how many wonderful get togethers I've been to in apartments and homes with old kitchens and friends gathered, and there is just as much heat,steam and grease with those small ranges crowded over with visitors and loved ones.

Hey feisty! Long time no see. What great progress you've made. And, yours is not the longest reno for a small kitchen. I'm right there w/ you, still! Don't start a new thread. Keep this one going so everyone can see the progress over time. I love love the tile! I actually chose blue like that for my backsplash. However, I haven't put mine up! So, as you can see, your reno is no longer than mine! I was moving along & doing well & then I brought it to a complete halt about 8 months ago. I'm now thinking about tearing my whole house down & building 2 on my lot! Keep one for me & sell the other. I'm still not sure if I'm going to do it, but I hate to put anymore $ into the kitchen, & whole house for that matter, if I'm going to knock it down. Still iffy on doing it, but am thinking seriously about it. We'll see. You have come a long way & it looks great. I think you should do the tile. I don't think it's going to be trendy & date the kitchen down the road. I thought the brass was going to be trendy, but it's still going strong. Go w/ what you like! I can't wait to see more!

@J Y Yes. We installed the two blowers in the Tempest II and have had it for over a year now. It was the best decision ever and the range hood is one of our favorite purchases during the kitchen renovation. It is not loud when you use it on speed 3 which is the speed we use all the time when cooking. We can still have a conversation in the kitchen at that speed without having to yell at each other. It has 6 speed settings and we only have to use speed 4 when we fry steak occasionally. The two blowers make such a huge difference in sucking up all the cooking smell. Can’t smell someone is cooking as normally the smell would travel up to the rooms upstairs. Very happy with Zephyr’s customer service as well as I called in a couple times prior to making my decision on a range hood and they had been very helpful in answering my questions. Let me know in case you have other questions.