The lights in my hood are on a strip of metal that occupies the front 3" of the capture area of the hood. They illuminate the entire rangetop, even the back really well. However, if I'm generating a lot of steam or smoke with a front burner, some of those fumes bounce off that light strip and escape. If I could have the lights in the back to avoid that bounce, I would have.

Keeping interior pressure constant has several benefits. As noted above, fireplaces and furnaces can backdraft. The fan itself will loose some flow rate with negative relative house pressure. If a fireplace is not an issue, then a separate feed to the furnace is possible in some circumstances to avoid backdrafting. I am aware that oil furnaces, for example, have such kits available. If the weather will support having windows open, then that may be sufficient. At the 300 cfm level, most houses leak enough air to allow ignoring the problem. Otherwise, a source of exterior make-up air (MUA) is needed. Opening a window is considered a passive source of MUA and may suffice. It certainly is the economical solution where feasible. If it is too cold to open a window, then it is too cold to use unheated MUA. This means that a rather large roof or side fixture is needed to let in air without rain and without significant static pressure loss, a fixture mounted or in-line fan is required, a heat exchanger is required, a source of heat for the heat exchanger is needed (one could use an extension to a hydronic system or use electric elements, or one of several other possibilities), and a diffuser and ducting are required to transport and dump the air into a room. The intake fan may need to be on a pressure sensing control loop. The basic picture is similar to a kitchen hood operating in reverse but with the complication of air heating. (Use of an air conditioning system to distribute the air can be considered if the heated air stays warm during transport. This may be the case where heat pump sytems are used for heating and cooling.) In order to not disturb the airflow into the exhaust hood so it collects all the cooking effluent it can, the MUA should enter the house volume well away from the hood. Ideally, the flow from MUA to hood should be over a large area at low velocity. My setup uses a large Wolf island hood (actually made by Independent) with 1500 cfm (at zero static pressure) Wolf (made by Broan) exhaust fan. The flow around the hood seems gentle at full fan power. However, my MUA system is not yet installed. If I move from the hood to a doorway in the path to where there are open windows, I can feel a considerable breeze flowing toward the hood. Calculate your kitchen volume (in cubic feet) and divide by the cfm you intend to use, and you will see that the kitchen volume is moved out of the house in a very short time, hence the need for MUA. However, a better (but crude) assumption is to use 2/3 of your rated cfm, because the exhaust fan will not be operating at zero static pressure. I guess the lesson is that if one wants semi-pro cooking capability, one needs semi-pro ventilation and MUA capability. kas

merk, have you looked at Kobe? They are supposed to be a decent hood but at a price that is less than Zephyr. They are made in China, which is one reason for their lower cost but it seems that they are still a decent product. And I think they come with 8" venting but I'm not sure since it's been a long time since I researched them. I used to also wonder what the big deal about venting was. We didn't use our pop-up downdraft for our island cook top often because at low speeds, it really didn't remove smoke or cooking smells and at high speed, it sucked the gas flame out. Back then, cook tops didn't come with automatic re-ignition so I never knew this had happened until I smelled gas. Not good! Even on high, it still didn't remove all cooking odors and smoke. The newer pop-ups are supposed to be better - they also rise higher so that helps them fight physics (smoke rises) but even so, they aren't as good as hoods. I started to learn about the importance of proper ventilation from GW and from my friend, a CMKBD. So we bought a good hood this time and I'm so glad we did. It works so well that I've never needed to turn it above low speed. I can't smell what's cooking on my induction cook top unless I stick my nose over the pan. My hood is 600 CFM but I think I could have gotten away with 400 CFM and saved the cost of MUA. If I had stuck with gas, I'm pretty sure I would have needed 600 because gas adds combustion fumes to the mix. Oh, well. We'd already ordered our hood before we did the tear out but once I saw how much disgusting yellowed grease was on my kitchen valances, I was so happy that I had spent the money on ventilation.

Tyler, so how is it going with the cooktop/hood? We are planning a remodel and considering a similar situation. We are in Florida, so I’d like to avoid MUA if possible as it is painfully humid and hot AF here 360 days of the year and one of my main goals of this remodel is to keep the hot air out. We have an older 1959 home, 94” ceilings. Our kitchen designer wants to put a 36” wolf gas range-style cooktop in front of a 104” window with a 6” backsplash/ledge using a wolf or zephyr 48” ceiling mounted hood at 600 or 700 CFM. So if the cooktop lands at 36”, that puts the vent 4’8”away from the countertop on the ceiling. I’m looking for functionality of suckage (sorry, I never made it past geometry into trig, so “suckage” is as good as it gets for me—lol) and if I have to use a different island hood that hangs 36” above the cooktop, so be it. I’m curious how it’s going for you, especially cleaning the window after cooking. Is it a daily chore or weekly? (I don’t see the window as a cleaning issue, when I cook, most of the splatter winds up on me or flies sideways, but rarely backward—but I’ve been wrong before, and I’ll be wrong again). I just don’t want to make the hood mistake. Any and all input is appreciated ;)