William B
Favorite Answer
The metal filter is also a dust & pollen filter and may have an electrical charge going to it,
thes were popular in the 60,s
you can change it to any one that fits,
Joyce B
Have you had it inspected lately? You could ask the technician who does the inspection what filter he recommends. Or you could call your gas company. Your furnace may work ok, but I bet it is incredibly inefficient.
I replaced my 1957 furnace when I moved into my house. The furnace was built like a tank, but was in no way efficient.
http://gasfurnaceguide.com/2010/when-to-replace-your-furnace/