I cannot have any kind of vent hood coming out of the side of my house, and I cannot attach anything to the house that requires drilling a hole through the wall, without submitting architectual plans-- because of neighborhood restrictions so If you live in a neighborhood with restrictions best to check with them also.

Well, I spent a bit of time searching the web and found out I have a Broan 643 wall cap, or something just like it. I also found out there isn't a whole lot more out there in an 8" size. There's got to be something better than what I have now. Anybody? Thanks!

Thanks! I noticed that the grille was greasy and when I removed it, the top filter obviously had been filtering. The fact that the holes on either side of the top filter had airflow and were completely open (there were no filters on them) made me think that something was wrong.

Not sure what part of country u r in or what type of construction or housing. In SoCal where I have lived, airing out a house is nearly daily even on chilly days up in the mtns. In the northeast, essential to have some outside air circulation in summer because of humidity and heat , essential in winter because of stuffiness and dry air. So in both cases we have managed with recirculating internal vents. THERE IS NO QU that externally vented are faster and more effective. ALL are noisy. In condos and apts we have lived in, there are restrictions on external venting... Can't vent within "x" feet of someone window, for ex., so do be aware of local code, Lastly, the effort and cost are a consideration depending upon where the vent will penetrate to the outdoors. There are split units btw, where the actual motor and blower are mounted exterior or remotely from the actual hood and fan... This is to reduce interior noise. Most don't come this way and the split is more costly to buy and to install... AND if it is a high volume (CFM?) I can tell you that the split is not that much more quiet. Good luck. You never know who and when you might be swept off into the rain bowed horizon