UPDATE #2 7/28/19 Fixed chatter! I got so fed up with the rattling that I tried to see if I could remove the fan to diagnose the problem. Luckily I was able to remove the fan from the bottom instead of the attic, which to my surprise and delight wasn't difficult: 3 screws. I turned on the fan after removing it to isolate the noise and it wasn't a fan. Then I looked at the plastic damper covering the duct and thought maybe that was what was causing the rattling. I removed it and reinstalled the fan. Voila! WITHOUT DIRT! It was a damper who "rattled and chatted"! Delta needs to do it again! 7/28/29 UPDATE The rattling is getting worse! One of the worst products I've ever bought. I would remove it if I could. I no longer have easy access to the location of this fan which soon got stuck until I redecorated my bathroom 3 years later! This is such a POS product! DO NOT BUY THIS! I bought it in July 2018 but finally got around to installing it as it's a hassle going through the attic. I hired my contractor to install it and he said it was difficult as the brackets are not standard and fixed. It took 4 times as long and cost me dearly. Much to my surprise, having just assumed the bulb was a screw-type bulb, it wasn't, but worst of all, I heard a rattling noise a few minutes after the fan was turned on. Now I'm stuck with this POS fanatic until buying a top brand and paying for another big install is driving me crazy.