I have a 35,000 BTU forced air furnace in my RV. I wanted to replace the heat registers as they were showing their age. I purchased three of these Valterra A10-3346VP Light Brown Rotating Heat and A/C Registers (4). They worked great on the two longer runs. Unfortunately, one of the registers is within 12 inches of the furnace. When the furnace runs, it smells of melting plastic (the plastic isn't actually melting). I thought after a few uses, the smell would go away. Nope. After several weeks of use, it is obvious it is getting too hot and creating the plastic smell. I decided to replace that particular register with a metal one. The other two that are further from the furnace and just fine.Overall, I think it is a fine product. Just make sure it isn't being installed in ducting real close to the furnace.