Old cast iron radiators, what to look for or lookout for?

[goosegunner]

Found a some radiators locally. Now that I have storage I was thinking of putting a few in my garage to take some more btus off my return water. I have forced air heat in my house and I am thinking if I can lower my return temp some more by sending return water through radiators I can heat my garage and help keep my storage stratified.


What do you look for with old radiators?

How do you size them for btu output?

gg

 

[benjamin]

Just the obvious, two pipes and a coin vent at the top, no scaling paint unless you plan to repaint them, no cracks/rusty water stains running down, and be sure to find some strong backs.

I think Heating help .com has tables that list all different sorts of profiles and sizes and gives the radiation per section at their rated temp (180?). You might be able to guess what they would put out at lower temp by derating them the same amount you would for baseboard?

If you already found them than this probably doesn't matter, but if it was my garage, I'd go for some simpleand thin art deco style. The Badger Army Amunition Plant/Specpro has some on a sealed bid auction closing soon if anybody is looking.

 

[Clarkbug]

Benjamin gave you some good tips. You should also look out for if they were used for steam or hot water. Lots of them can be used for both, so thats not a problem. The issue is that the steam ones were only ever subjected to low pressure, so you may want to pressure test them some before you pipe them in, since your hot water system will (most likely) be at a higher pressure than the steam would have been.

 

[salecker]

Hi Goose
I'v picked up about twenty rads a couple of summers ago.
I was told to preasure test them to 80 psi,then flush them out with a mixure of warm water and 10% hydrocloric acid,rinse and retest to 80 psi.
I picked up a small electric water heater have a plastic well pump,a couple of plastic drums and this will be one of large messy jobs that i have left.
I'm hoping to get enough to use throughout our house,so getting the info on output of diferent rads is timely for me,
I'm going to fill the rads with water to get 80psi add air,and hope they are all fine.
Thomas