Replacements for 103-year-old steel coil radiators

BillConlan

The gravity boilers in my duplex are 103-years-old this year. The boilers and the gas conversions installed in the '60s are working well. The problem I'm having is with the radiators.
The original radiators are not cast iron. They are coiled tubular steel about 30" high. The coils range in diameter from 10.75" to 14."
Over the years, some of them have rusted through and have distorted too much to be welded. The smaller ones in the rear of each unit are still working but the larger ones have had to be removed. We're using fans to bring heat to the front of each floor.
Upgrading the heating and electrical systems in this building will cost more than it's presently worth; complicated with my being 88-years-old.
Are there any panel units that can replace these old radiators? I've seen some tubular cast iron radiators but, including shipping, they cost more than three times that of panel radiators. I need 4 of them.

Jamie Hall

A radiator is a pretty simple device… I would say that almost any panel radiator will do, provided it's big enough. And "Big" is defined by surface area heated, so you could measure some of those old coils and figure their surface area by calculating the surface area of the pipe itself (the pipe circumference times its length).

A more interesting question is going to be connecting them to the existing piping!

Pictures?

mattmia2

is this a pumped system or a gravity system? I assume if the boiler is 100 years old that it is a gravity system. In the case that it is a gravity system, I would recommend using cast iron radiators as replacements because panel radiators will be too restrictive for gravity flow. US Boiler makes a line of cast iron radiators of 3 common styles.

For that matter, is this hot water or steam?

kcopp

pix please!

BillConlan

RadiatorTopView.jpg

BillConlan

RadiatorTopView.jpg

RadiatorBottonView.jpg

EBEBRATT-Ed

Kind of looks like copper to me but pictures can be deceiving.

I think it will be difficult to come up with a rating on those units. Never seen anything like it.

@Steamhead ?

mattmia2

looks like a rolled up mattress radiator, looks like steel or sheet iron to me because it is rusty. if you can't find a spec for it, using geometry or calculus to find the surface of it assuming it is just a 2 sides rolled up rectangle will probably get you close enough.

Steamhead

I've seen something on these but can't find it quickly. Since this is a low-mass type of heat emitter, it would be well to stay with something similar. Possibly a convector such as Beacon-Morris makes.

We might get an idea of its output by looking at the size of the pipes feeding it. Given its age, I'm thinking the water originally circulated by gravity, so we'd go to the design info of a gravity system.