I see you created two threads for this. I'll repost what I wrote in the other thread for continuity. ------ I have the Weber Performer. It's an awesome grill. I used a Weber kettle for years with great success, but in a moment of weakness I retired it for a Weber Genesis gas grill. Gas grilling is convenient, but it's not the same. Last year I purchased the Weber Performer to get the convenience of gas starting, but the cooking flavor/performance of charcoal. First, the propane assist is just a charcoal starter. I stack the charcoal in a compact pile over the starter and ignite it. Of course the bottom vents are wide open and the lid is off at this point. After about 3 or 4 minutes, I can hear the charcoal snapping, popping, and smoking to indicate it's "lit." I turn off the propane and let the charcoal burn down until nearly all sides are covered with fine layer of ash. Then, I knock the pile down and spread it evenly across the bottom grate for cooking. Now, I put the top grate and the lid on and open the top vent wide open. I watch the temperature climb to >400 degrees, then open the lid and brush the top grate to clean it. Close the lid and use the upper and lower vents to control the airflow and thus the temperature. After some experience, I know just about how much to close them down to hit a temperature range I'm after. This assumes you're using good quality charcoal and not using too much of it. I prefer the hardwood "lump" charcoal. The old standard Kingsford briquets don't seem as high quality as they once were. If, for instance, I'm cooking hamburgers, I'll have just enough charcoal to cover the bottom grate with the chunks spaced 1/2" to 1" apart. Hamburgers cook pretty quickly. Don't use the little half-round trays Weber includes to hold the charcoal for normal grilling. Those are for special circumstances when you want indirect heat. When I'm done cooking, I close all the upper and lower vent to extinguish the charcoal. I use the leftover charcoal from the previous grilling as the base of for the next cooking and add a little more from the bag to make the pile I want. One more tip, use the lower vent control lever in a back-and-forth motion BEFORE you begin to sweep the ashes into the built-in collection can. Clearing out any build up debris in the bottom of the kettle helps the airflow. Return the lower vent to full open position before lighting the new charcoal. If you aren't getting to the temperature you want, you may have crappy charcoal, inadequate airflow, or impatience. ------ After reading the additional information you posted in this thread, I'd want to reemphasize the need to mound the charcoal tightly on top of the propane igniter for the initial lighting and burn down. Turn the propane ALL THE WAY ON and leave it that way for the 3-5 mins it takes to light the charcoal well. It should sound like a weak torch with a touch of whistle to the outlet flame. Let the charcoal burn down in its mound before spreading it. Lid off and bottom vent fully open for the initial burn down. The propane igniter works great.

The 2009 code in many cold weather states require MUA systems for over 400 CFM M1503.4: "Exhaust hood systems capable of exhausting in excess of 400 cfm shall be provided with makeup air at a rate approximately equal to the exhaust air rate. Such makeup air systems shall be equipped with a means of closure and shall be automatically controlled to start and operate simultaneously with the exhaust system." "Makeup air required: Exhaust hood systems capable of exhausting in excess of 400 cfm (0.19 m3/s) shall be provided with makeup air at a rate approximately equal to the exhaust air rate. Such makeup air systems shall be equipped with a means of closure and shall be automatically controlled to start and operate simultaneously with the exhaust system." A2 is strictly enforcing this. I decided to go induction and stay under the 400 CFM. I was leaning toward induction and this just tipped the scale. I am probably going with a Broan evolution hood @ 350 CFM and 4 halogen bulbs using theater lighting. The zephyr genova is very discreet, but concerned that the single fan on the left might not do the trick (only 250 cfm). The ventahoods have a true HEPA filters. I figure A2 is pushing me into the future. If you go too high on CFM, there are dangers, so I plan to avoid the problems! Good luck!! PS - I plucked the Wolf induction on sale. Love the appearance of the surface and had no trouble with the controls - I used my knuckle to tap the power up and down when my fingers were slimed! I liked the large burner and the set up of the burners and only one cook as my husband only knows how to order pizza and not cook. I only tested it at the appliance dealer, so can't wait to the kitchen is done and I actually can really test it.

Try searching for "decorative grille inserts" and you'll find a ton of websites. Here is one: Here is a link that might be useful: decorative grilles

Installing an outside exhaust fan would pull out conditioned air. It is not a good solution. The second floor should have a return vent. Is there a way to extend the existing return to the second floor? The return does not need its own fan.