Paint it the same color as the walls and you won't notice it.

Thanks - should we have them line the metal with something though? Just painting it as is will still show the dents and holes in the metal...?

Adhere a piece of metal over the back of the duct with the hole, paint the inside of the duct the wall color.

Actually I have some black grates in my house and I painted the inside of the ducts black and the pattern of the grate is still obvious, although maybe not as highlighted as you would like.

Clean the metal duct best you can or ask the contractor too and then place an additional metal sheet (another layer on the sides), you can put similar color sheeting behind the grate to cover the empty space inside if it still continues to be an eyesore to you.

You can raise the grate too so it covers the bottom empty parts of the wall if that makes

Clean the metal duct best you can or ask the contractor too and then place an additional metal sheet (another layer on the sides), you can put similar color sheeting behind the grate to cover the empty space inside if it still continues to be an eyesore to you.

Thank you for the suggestions! All things that I'm sure will work aesthetically and I didn't know was possible as a layperson.

The solutions don't account for new cover having a filter. Removing filter from return air sounds like a poor idea regardless how it might look.

This was originally a see thru double-sided supply vent that is now only one-sided and needs to be used as a return.

I understand you are focused on the aesthtics but lets talk about the functionality for a minute. This was orginally an old supply vent, but the contractor turned into a larger return vent with a filter. Was a new HVAC system installed as part of this remodeling project?

The contractor at your request and with additional funds has made this return vent smaller and will now have no filter. Where is the new location of the filter? Is this the only return vent? If it is then I would be concerned it is undersized and will likely be very noisy when the AC is operating.

Can you provide the information on the new HVAC system (brannd, model, etc.). This will tell us the size (BTUs) and how much return air and filter size is required.

Hello! @mike_home Thank you for your response - no, we did not get a new HVAC system.

The vent is located at the HVAC unit, which was the original location. This is not the only return, we added a second return for better airflow and to compensate for this change.

The HVAC system is not new but I think it’s a Carrier. It's my understanding that they’ve already calculated all of this info..we’re using the original 16x25x2 filter. Thank you!!

@klem1 I agree! Filter is located on the HVAC unit (my understanding is that this cuts down noise as well.)

If you did not get a new HVAC unit then why was it necessary to change to original supply vent to a return? If the filter location has been relocated, then make sure you have easy access and can change it yourself.

Now that this vent is a return, are you going to add another supply to the front room? If not are you sure this will not affect the temperature of the front room?

This was originally a see thru double-sided supply vent that is now only one-sided and needs to be used as a return.

Now that the filter has been moved to another location, I don't see why this could not be a doubled-sded return vent. Ask the contractor if this is a possible. That would restore it to what it looked like originally and eliminate the aesthics problem.

thanks @mike_home!

This supply was originally for the original furnace to the home. It was changed into the only return for the house when the current HVAC was installed (prior to our purchase of the home 13 years ago). The filter location is as it was prior to the contractor changing the return in question – all good.

-Another supply is not needed, this “supply” has never been used as a supply with the HVAC system – only the original furnace.

It can't currently be used as a double-sided as the other side has been covered up by new cabinets in the kitchen as part of the larger remodel, hence the change in the first place. So basically, with all of that being to code, we are really just looking for a "proper" way to make this look nice.

What is the width and height of the new return opening?

Due to unknowns I don't feel good about making recommendations. Had the contractor walked off the job I'd be more prone to helping you work things out. As it is I simply can't understand why you decided to micromanage this vent based on input off this forum. I'd expect contractor's firsthand knowledge to be in your best interest.

hi @mike_home the opening is 20' x 17", but open down through to the basement level.

Hi @klem1, that's fine. I'm not looking to micromanage anything. Our contractor specifically requested our input regarding the aesthetics of the finish as she said it was not something in her purview. I was merely looking for ideas or others who have experienced something similar.

interesting idea - thank you @kimberly_j_strange

Can you paint the interior of the return? The metal that you can see through the grate? A matte black would hide most of what you don’t like seeing and shouldn’t impede the functionality of it.

One possible option is to install a return grille behind your vintage grille. Return grilles usually have horizontal openings with the louvres pointing downward. This hides what is behind the grille. Using a color similar to that of vintage grille will make it less noticeable. The closest grille I found is a 20 X 16 inch in black. You could either mount it to the opening or to the vintage grille itself. You could also spray paint the grille to get an closer match to the vintage grille.

Here is one example I found on Amazon. You may find something you like better are web sites that specialize in custome grilles. Black 20" X 16" Steel Return Air Grille

thanks @User, yes we could paint it. I was just worried that the sloppy inside would still look bad, just painted bad. I think lining it first with either clean metal or drywall or something else before painting is probably what we will need to do.

Thank you for the suggestion @mike_home I really appreciate it!

Paint it flat black on the inside. In a month or two you'll never notice or think about a few dents.