I was searching the internet for a specific answer and came across this site. Bear with me as I will probably confuse many. We have baseboard gas (hotwater?) heaters currently. They seem old and are metal or cast iron perhaps? I can't find a picture anywhere, but my question is, we want to change the covers for an updated look. How can I accomplish this?
You could post a picture and perhaps someone will recognise what you have. Beyond that, generally, I think you will find it difficult to attach a different style cover to old baseboard. Having said that I have been known to be all wet. The question to me is how much of a project do you want to make of this? In my home I just bit the bullet and as I renovated different rooms I'd just cut out the old and start fresh. That worked for my wife, so I guess that means it worked for me too!
It could be Slantfin or Sterling and each has several lines. I often get this question and it seems it gets to the pricing stage and what is involved to do it and no further. You could also use radiant panels or radiant panel radiators to replace them. It would be a good time to increase the amount of radiation so you can lower the system supply temperature to realize a fuel savings.