National Art Radiators

Harvey Ramer

Anyone have the specs and ratings on these?

Steamhead

If they are the "small-tube" type (section spacing 1-1/2 or 1-3/4") the ratings were standardized, so the chart for any similar units (as Burnham Slenderized in "E.D.R.") would work.

There was another "Art" radiator line made by Union Radiator Co, which was absorbed by National at some point. These were large-tube radiators similar to the National Aero.

Harvey Ramer

Thanks @Steamhead !
That gives me the info I need. These are the small tube type.

The system also has weird plumbing. There are two s/r mains, both 3" the whole way to the end. The one set does the one side of the house and the other set does the other side. All the takeoffs come vertically off the top of the pipe. The branches are all 1" except 2. The radiators are bottom piped, s/r. I saw no evidence of previous air vents or steam traps. The layout hardly makes sense for gravity water unless uneven heating was their goal.

I am converting the system to a TRV system with a new boiler. But I am curious about the original intent.

Steamhead

It was gravity. This type of system typically carried the mains full size all the way to the end. I guess they did this to keep pressure drop low.