Old cast iron radiators

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wrightk20

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Nov 1, 2012
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A friend of mine is having a new heating system installed in his house and he is taking out all of the radiant heating system and installing a forced air set up. I was wondering if the cast iron radiators are worth keeping to use to heat a garage or something. Everything was functional when it was taken out. Seems like they would be a better solution than a air to water hx with a fan. Also can they use water down to say 100*F and still throw good heat? Thanks for any info. Kevin
 
Kevin,

Don't hesitate to put these radiators back to use they are wonderful,I all ready had forced air in my house when I installed my rads and couldn't be happier,mine are set up to have 110*F leaving my storage system and returning at 90* for an average of 100*.

As more and more people are scrapping these old rads they are getting more scarce all the time,there is coming a time when your going to wish you had a stock pile of them.When I bought mine I bought extra ones just to make sure I had a enough to do my job,last week I sold 7 extra ones I had and a heating contractor drove 60 miles to pick them up.

Jeff
 
I just recently converted from forced air water hx to cast iron rads. Wife says that was one of my best ideas yet. Cosy, quiet and more efficient.
 
A friend of mine is having a new heating system installed in his house and he is taking out all of the radiant heating system and installing a forced air set up. I was wondering if the cast iron radiators are worth keeping to use to heat a garage or something. Everything was functional when it was taken out. Seems like they would be a better solution than a air to water hx with a fan. Also can they use water down to say 100*F and still throw good heat? Thanks for any info. Kevin
Don't listen to these people. Those radiators are worthless, even dangerous.

Listen, I'll come and take them off your hands.....;)
 
Thanks guys. I'm thinking of possibly installing a few in my basement. I have a car and a half garage in the basement and i would like to run radiant instead of using the forced air ducts. I would probably seal them off. How would these radiators be plumbed? Are they suppose to be in series or in parallel off of a manifold? The ports on the radiators are pretty big. Do i need to run large pipe to them or can i reduce it down and to what size could i go? Kevin
 
Thanks guys. I'm thinking of possibly installing a few in my basement. I have a car and a half garage in the basement and i would like to run radiant instead of using the forced air ducts. I would probably seal them off. How would these radiators be plumbed? Are they suppose to be in series or in parallel off of a manifold? The ports on the radiators are pretty big. Do i need to run large pipe to them or can i reduce it down and to what size could i go? Kevin
From what I've seen in remodels they're run in series like regular baseboards, or if you're handy with the pex each radiator is home run back to a manifold and zoned. These oldies were made for steam, and there's a lot more heat in FWH so you don't need to run such a big line. 3/4" is big enough for a typical loop, and 1/2" is (probably) more than enough for a single rad. I've seen them run on a monoflow (parallel) loop with one main in/back that is pumped and then tapped to the individual radiators, each with valves so you can zone at each rad.

One caveat is to realize these radiators were sized for a lower temperature than typical forced HW. They really shine when you couple them with a outdoor reset control that will modulate the boiler temperature depending on the outside temperature. They take a longer to heat up and cool down due to their mass (and the water volume they hold), so a radiator sized for 120-140 degree steam will blast you out of the room when converted to 180 degree water, and hold it a lot longer. The ornate castings of some rads were actually to increase the surface area, and therefore the heat output.
Cast%2BIron%2BRadiators.jpg


They also don't take up as much wall space, and make the ultimate spot to dry your wet clothes.
 
Like having a little wood stove in every room. And, they're beautiful works of art, IMO. I simply clean them off and paint with Rustoleum spray paint. The finish lasts a long, long time.
 
Another thing. Are they hard to bleed the air out of? I'm thinking that they have air bleeders high on them somewhere. Also would it be a proper thing to install them under a window? Seems like all the ones that i have seen are located under a window. Kevin
 
I've been looking for some CI rads for a long time. Someone would have to be insane to go from FHW to scorched air IMO. The only benifit is the ability to air condition, and maybe a quicker response time (a draw back to me) makes temp swings in the room. Grab those while you can.

BTW, I installed a CI rad at my uncle's place a month ago (along with baseboard and radiant slab in another portion of the building) all fired with a Harmon pellet boiler. I used 3/4" copper and a bleeder elbow on the top conection for air elimination, since the old 1/4" plug was not comming out easily. Be sure to pipe the supply to the top connection on the rad. If I were to do my whole house with CI I would use 1/2" and do a manifold setup. They need little water to put out the heat, somewhere in the 1/2-1 gpm for typical sized units. Very forgiving in flow, less is usually better.

TS
 
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Another thing. Are they hard to bleed the air out of? I'm thinking that they have air bleeders high on them somewhere. Also would it be a proper thing to install them under a window? Seems like all the ones that i have seen are located under a window. Kevin

Bleeding the air isn't hard if the valve works, basically a couple minutes per year for that. Also the valve can be replaced relatively easily. They're placed near windows or the coldest part of a room to aide convection, it helps prevent cold spots in each room.
 
FWIW keep them even if you don't use them. At my day job we acquired a property that uses them. Unfortunately someone stole two of them. It was almost impossible to find them and when you do can be worth some $$.
 
I have collected 13 radiators for my place. The will most likely end up in garage and shed. Wife wasn't to keen on putting them in the house.

gg
 
I think their beautiful, even the plain ones fron the 50s. You either like them or detest the looks I guess. I still want to put some in the upstairs bedrooms, but the Mrs. isn't keen on them either, kids burning their hands on them, I say they will only do it once.

TS
 
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My wife hated the idea of these rads in the house until we actually started using them,Mine are all the shorter to medium size ones(14"-22" tall) that are perfect for sitting on and with 100* average water temp there is no risk of anyone getting burned.Now I think the bigger fight would be if I decided to remove them.

As far as piping I have a supply and return running the length of the house both 1" pex (think long manifold) ,from the supply I have 2 rads in series to the return with 1/2"pex,this is done 4 times for a total of 8 rads.
 
Great for drying boots, mittens, ski gear, etc. My wife likes to hang the sheets on the line in the winter, then bring them in and drape them over the radiators, and the whole room smells like fresh linen. It's nice. The bleeders are cheap if they need to be replaced. They screw into a 1/4 tapping at one of the top ends. I bleed mine once a year, whether they need it or not. The ones downstairs rarely do; the ones upstairs generally collect some air over the course of the heating season. As for piping, I go in and out of the bottoms. Works great. The shorter ones are harder to find and can be more expensive than the taller ones, mainly because they fit under most windows, while the larger ones take up wall space.
 
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