Is It Safe To Cover A Floor Vent With Furniture . You can usually find full sheets of magnets at craft or home improvemet stores. If you place furniture atop a vent, it may dry out the wood and damage your expensive sofa or armoire.
Wooden vents, which are especially susceptible to intense heat. You may also cause your furnace or air conditioner to work harder, resulting in a higher utility bill or premature wear to your system. I have tried many things to cover vents with and i find large magnets work best.
Look into the vent, right where the ductwork meets the floor.
For sizing, please use the duct size and reference the overall frame size for installation. So, it would be safe to add an extension if your floor vent is behind furniture or something. The subfloor is almost always wooden. Perhaps your vents are located on side walls or even on the floor.