There are different solutions depending on the size of the hole in the wall - small holes can be patched with painter's putty, while medium sized holes require a drywall metal patch and larger holes require patches made of drywall.
We installed HVAC in our house and hired Raymond to drywall over the vents. Unfortunately one of the main vents had to installed in a very awkward location in our home. We decided to cover it up with built-in ...