Thanks for all your replies. The house has not broken ground, so I have some time to decide. When I installed my parents's range hood, I was limited by their house's 7"-diameter duct. I don't want to run into this problem with my house. I am planing to install a unit with approximately 1000-1200 CFM. Hopefully, this will eliminate almost all of the odor. The Kobe that I came across on here looks promising. I put a Zephyr in my parents's kitchen, so I have experience with that brand. Like weedmeister says, I am leaning toward doing it up front. I just wonder about cost. I think the builder is going to charge a few thousands for this.

Wow -- I didn't mean to turn this into a Middle East Crisis. Trevor: Terribly sorry if I offended you and Karen. I tried to be honest when I came into your store that I was committed to a contractor who was doing my installation and would only install the range if I bought it through them. To make up for the trouble of coming in and cooking on your range, I wrote up about my wonderful experience with you on my blog. The last thing I wanted to do was "milk" you. If it came across that way, I am sorry. My contractor was disappointing. But no one else was going to take such a small, but complicated job (it was a completely finished kitchen that needed granite cut on site to fit the range). I was hoping you might be willing to help me trouble shoot this problem the same way I reply to people who write to me with cooking questions even if they never took classes from me and never will. But I realize now that I've unintentionally offended you, so I understand your reluctance. I am not trying to get anything for free here. The only reason I mentioned the bills was that no one seemed to know what the problem was but agreed that the oven wasn't running as expected. I am perfectly willing to pay anyone who can fix it. I'll try to answer the other questions people have asked: Vesco did the conversion and I wasn't charged for it. Unfortunately, they didn't let the oven run at all after the conversion. They told me I had to burn it in and left before I had a chance to do so. Vesco came out the second time. They were here for 5-10 minutes. They said they adjusted the air shutter, but didn't hang around long enough for me to demonstrate the really loud noise to them (that only happens on the second or third cycle of the oven and usually at high temperatures). Unfortunately, their tool for testing the propane pressure was broken and they told me that the problem I am describing is probably the propane pressure dropping sometimes. The propane company came and hung around for a while. I was able to reproduce the oven noise problem for them and they thought it was a no-no. They were taking the propane pressure measurement the entire time and it didn't change at all before or after the noise. It stayed at 12 wc. They got on the phone with Bluestar and Matt told them to bring it down to 10-11, but didn't think that was necessarily the cause. They brought it down and we couldn't reproduce the problem, so they left. I had it happen once again, but not as badly as before and it only happened once. A friend of mine just bought a bluestar from Eurostoves and said that Trevor was very helpful with trouble shooting the problem. He is also on propane and is having the same problem (or so it seems -- he describes it as jet engine noise). He says that it might be the orifice for the oven that needs to be replaced. He is waiting for a technician. I have another general question about the oven. My oven's normal state sounds as if someone is blowing at the flame and it's constantly reigniting. The easiest way to reproduce that sound is to turn on one of your stove top burners and blow on it couple of times. It makes a whooshing sounds as if it's going to go out, but then reignites. Is that normal? Also when it comes on, it makes a relatively loud puff sound. I do hear banging sometimes when it heats up and cools off from the metal slightly warping. Do I need to worry about that? Besides all these strange things, it cooks and bakes great! I just want to make sure it doesn't self-destruct in the process.

Your contractor has no clue what he is talking about. Building and Mechanical 'Codes' do not address residential range hood installation requirements...and instead defer back to the manufacturer's installation instructions for vent termination heights and clearances in cases like these. Your contractor obviously did not read those instructions. So find a new contractor who can read them, and install your range hood duct termination as it was intended to be installed.

@sarina: I have had the Kobe RA02 for about 8 months now. Being an engineer, I did the install myself, although the chimney cover is still not in place, as I need to redo the crown molding behind it (procrastination is the name of this game). Overall I like it, but that doesn't say much, as my previous ventilation was just a fan-in-a-ceiling-hole. The quiet setting is quiet, but the other two are noisy; without previous experience, the "sones" numbers don't translate well into actual noise levels. Otherwise, on High, the hood is pulling out all the smoke and airborne grease steaks in a cast-iron skillet produce. You will have to open a window or install a MUA to help it pull all that air volume. The baffles need scrubbing every month or so, but that's a very small price to pay for not having cabinetry and walls smeared in grease. The model you're looking at is a little more elaborate, as it has some sort of electronic control. The RA02 is bare-bones, just two rotary switches.