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Cast Iron Radiator Project

Post in 'The Boiler Room - Wood Boilers and Furnaces' started by Eric Johnson, Oct 29, 2007.

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  1. Eric Johnson

    Eric Johnson Mod Emeritus

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    I can tell you that my wife was absolutely thrilled to be seen with a guy taking photographs of radiators on his vacation.

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  2. 88rxn/a

    88rxn/a Member

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    i think mine are crane

    kenny chaos:
    do you know what type of rad. yours is?
  3. kenny chaos

    kenny chaos Minister of Fire

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    Don't jump to conclusions fellas. That was just a pic off of google image.
    I do have a couple out in the barn I dragged over from the old house.
    They look like your green ones except mine are an off rust white color.

    Is it okay to mix and match the ci with my existing baseboard.
    I don't see ever being able to do it all at once.
    I did a search on craigs and see two different adds right now! Very tempting for an impulsive guy.

    I appreciate your guys ideas of beauty.
    Donl likes this.
  4. Eric Johnson

    Eric Johnson Mod Emeritus

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    You're not supposed to mix baseboards and cast iron radiators on the same zone because they have different rates of heat output and for some reason that's supposed to be bad. I guess if you had a zone with baseboards in one room and radiators in another room and the thermostat was in the room with baseboards, the other room might tend to overheat. Anyway, it's a no-no according to the pros. I say: if it works, it works. And I think it would work. One well-placed cast iron radiator will replace many feet of baseboard.
  5. kenny chaos

    kenny chaos Minister of Fire

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    Anybody know off hand how many btu's my old baseboard is rated?
    My main objective for switching to rads is to get more heat.
    Thanks-
    Ken
  6. danmitchell9

    danmitchell9 New Member

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    We had fintube and cast mixed together on the same zone. Seemed to work OK. But I've heard the same; that it's a no-no to mix em. Just make sure you don't use steam radiators. I had a steamer mixed in, and it gets airlocked above the bleeder valve, which is only 2/3 up the side. It heats, but only below the valve.
  7. EForest

    EForest Member

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    My brother just installed a (gas fired :sick: ) Viessman condensing boiler in his old house with cast iron steam radiators and converted them to hot water with this steam to hot water conversion valve. His house has never been more comfortable since. You need to ditch the black pipe and run 3/8" pex supply and return to each rad from a manifold. It was a surprisingly simple task. that pex is easy to snake up walls.

    Ed
  8. kenny chaos

    kenny chaos Minister of Fire

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    Obsessing:

    I need 15,000 btu/hr for the big room.
    25' of baseboard at 600btu/ft= 15,000btu/hr so it should suffice- it doesn't
    I figured the two radiators I already have at a combined 21,000 btu/hr. Is that 25% more or 30% more?
    Either way, those two rads alone should help tremendously and more efficient?

    Thanks-
  9. 88rxn/a

    88rxn/a Member

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    the guy i bought my STEAM rad. said to plug one end into the top of the side then out of other side at the bottom? has anyone tried it this way?
    one of my rads will go into the kitchen at the end of my baseboard loop for down stairs. what i will do is make a bypass going to the rad with valves on both sides (2 "T's" on the main line making a center section) and valves on the center section below it on the main line. this way i can "feather" the flow to the rad or totally shut it off or run it full bore if needed.

    kenny, im using HAYDON baseboard, its rated at 610BTU's @180F.
  10. Eric Johnson

    Eric Johnson Mod Emeritus

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    I don't know about more efficient, but I suspect you'll get a lot more heat.

    Piping radiators is a point of contention. I always pipe into the bottom and out of the bottom. You have to think about whether you want them piped parallel or serial. Serial is easier and cheaper, but it won't work if you have too many rads on the zone, because the last one(s) in the series will always be cooler. The best way is with monoflo tees. Don't ask me to explain how they work, because I have only a vague idea. But it distributes the heat evenly to all the rads in the zone.
  11. NHFarmer

    NHFarmer Feeling the Heat

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    I converted my house from steam to hot water.I used 1/2 pex,Feed in the top return out the bottom.They are working great.I agree with Eric,I don't really think it makes much difference but that is how I piped mine.I also used a manifold setup so each rad. has its own loop.
  12. kenny chaos

    kenny chaos Minister of Fire

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    Why have each rad on its own loop?

    Isn't it true that you can control the heat of an individual rad by adjusting its valve?

    Thanks-
  13. Eric Johnson

    Eric Johnson Mod Emeritus

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    Basically, what he's talking about is having a main line with branches for each rad coming off it it. If you think about it, if you pipe them in series, any flow restriction on any individual rad will slow down the entire loop. With a monoflo tee setup, you can throttle each one down to your heart's content, and not affect the others. In theory, anyway. It's a more complex and expensive way of doing it, but it's also the right way. That's the way 13 of the rads in my house are piped. On the one that I installed myself there are only two rads--one for the kitchen and one for the laundry room. I ran them in series, because the rads are sized for the rooms, and so I don't restrict either one.
  14. kenny chaos

    kenny chaos Minister of Fire

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    Yeah, okay. I got it. That's the way my baseboard is, one loop all the way around the basement with branches. And you're calling each branch a loop. Doesn't each rad have a valve to control the water flow thru it, located right there at the rad? And it can be used as a thermostat, sorta?
    thanks-
  15. Eric Johnson

    Eric Johnson Mod Emeritus

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    So you're all set. Don't worry about it and just replace the baseboard with the radiators or pipe the rads in series with the BB. If you do that, make sure the BB comes first, followed by the ci rad. The BBs need much hotter water than the rads. That's another advantage to cast iron--you get more usable heat out of your boiler. Not as good as infloor radiant, but def. better than baseboard.
  16. kenny chaos

    kenny chaos Minister of Fire

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    Don't aggravate me Eric. :coolgrin:
    I do have the option of switching to radiant floor. How much more efficient is it?
  17. tom in maine

    tom in maine Minister of Fire

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    My last house was a two pipe steam system with beautiful old radiators.
    I moved in on Jan. 10. It was -20 that night and the house only got up to 55F. We sorted out the problem and the next night,
    it was 85 upstairs and 65 downstairs.
    We then installed thermostatic control valves on all the radiators and made the whole system work as well as it was going to.
    Thank God oil was cheaper then.
    I proclaimed the end of the heating season and took the recip saw to the hole system, except for the radiators.
    BTW, the old oil boiler had a 12" flue!!! and some genius had installed a gate valve on the pressure relief valve!!!!
    AND it was shut!!!! Rocket ship boiler in Bangor, Maine!

    I plumbed it with 2-3/4" feed and return lines with 1/2" branches to each radiator. I installed ball valves in the basement wherever it fed the radiator.

    I had to install coin vents on all the radiators (there was a plug where it went) and made the system into a hot water system and used the original lower fittings.

    In hindsight, I could've done it with a manifold system, but this kept the plumbing in the basement to a minimum and got the heat upstairs faster.

    Ran the whole thing on an outdoor reset controller.

    My friend, Dick Hill did some wood boilers using old radiators as the boiler heat exchanger. Worked very well and even if bought new, was a pretty
    cheap way to build a boiler from scratch!
  18. rickh1001

    rickh1001 New Member

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    Eric,

    I didn't catch your original post on this, but you are way ahead of your time. These old "radiators" are just that, as in Radiant Heating. I have been looking at alternatives to the plenum hot air HX's I put in mostly as an expediency to get the job done. However, into the end of the first heating season, I have been looking for ways to transport the heat with lower temperatures, and radiant is the way to go. Trouble is, gorgeous old radiators like you show, have gotten very expensive. These used to be junk items you could pick up for almost free - now they are works of art. Radiant heat panels are still not cheap, although they are only a few times more expensive than baseboard. After getting the boiler installed last year, just in time for the heating season, next year's goals are to insulate/insulate/insulate, then to replace the HX's with a heat delivery source that can be effective at much lower temperatures. Beautiful old radiators would be just the trick.
  19. kenny chaos

    kenny chaos Minister of Fire

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    Eric- from your pics, it looks like the one is mounted about six inches from the wall. Could you share any thoughts or ideas, or "rules of thumb", that say to place under window, six inch clearance for proper air flow, whatever? Anybody?
    PS- cool greenhouse

    Thank-you to all the contributors of this thread. Five pages of just good stuff.
  20. DaveBP

    DaveBP Minister of Fire

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    Ignorant machinist's question:

    If you have a CI radiator that has no provision for air bleeding or you want to install one in a way that makes an existing bleeder tough to reach, can't you just drill and tap where you want with the appropriate drill and pipe tap where you want it and install a your favorite bleeder. I realize it would be sacrilegious to modify those ornate and beautifully restored pieces but for your everyday radiators, why not. Most cast iron is easy to machine (not white cast iron like brake drums ).
  21. 88rxn/a

    88rxn/a Member

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    cant you just bleed them with the coin screw?
  22. Tarmsolo60

    Tarmsolo60 Feeling the Heat

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    Thats what I did to some old steam radiators I converted in a house I used to have.
    Some even had a nice flat spot where you could drill near the top, or you could drill the threaded plug also.
    It looks like radiator in Eric's post #7 didn't have either of those options, If it ever got air bound though I think I'd be driiling and tapping near the top anyway.
  23. Eric Johnson

    Eric Johnson Mod Emeritus

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    It's all about usable heat. I think you can put 80 or 90 degree water through infloor or staple-up radiant and still heat with it, while you need hotter water for ci rads and even hotter water for baseboard. So the point is that you can get a lot more usable storage if you can draw it down to 80 or 90 degrees, instead of having to recharge it when it hits 120. It gives you a bigger battery.

    As to radiator placement, it's best to put them under a window. My rule of thumb on distance from the wall is far enough away so that you can get a paint roller behind it.
  24. Eric Johnson

    Eric Johnson Mod Emeritus

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    You can drill and tap cast iron. Some old radiators have a thicker spot, often with a little dimple for starting your drill, cast into the top of the radiator ends. Most people try to take the top plug out and replace it with one that can accommodate a 1/4-inch bleeder. On the old steam rad in my kitchen without a top pipe, you'd have to tap and drill each column (there are maybe 15 total) to bleed all the air out of the radiator, since each column traps it own air. Believe me, I thought about it. Not practical. That one is on its third heating season since I originally installed it, and it still produces an insane amount of heat, so I doubt there's much air caught in the tops of the columns, if any.

    My old house, which I sold to a colleague, has an old hot water system originally designed for coal. Somebody retrofitted the coal boiler to oil at some point. I tore it out and put in a combination wood/oil boiler. The beauty of that setup is that it's all gravity feed. No pumps on the system at all. All you do is fire up the boiler and the water circulates naturally through all the rads in the system (2 zones). The trick is large-diameter pipe. In this case, it's 2.5-inch pipe branching down to 1" to feed the rads. The house, built in 1910, has no insulation in the walls, original double-hung windows with aluminum storms and the original clapboard siding. It's in the Adirondacks, where -30 temps in the winter are not uncommon and the power goes out on a regular basis. As long as you keep wood in the boiler, it stays nice and warm, power or no power.

    Here's a pic from 2002 of one of the rads in that house. We still have the same stupid cat, and he still parks his ass on or around various radiators for the duration of the winter. You'd think he'd be happy, but he complains all the time.

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  25. Paso

    Paso Member

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    Darn I drove by the local scrap dealer and someone threw off 3 cast iron rads in the area of free dumping.

    I looked twice at the old rads and didn't load them up, after reading this thread I see how stupid I was for not taking the time.
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