Hoping someone can point me in the right direction. Basically we have an older home, which has undergone a lot of renovations. We are in the North East, Gas How Water Boiler with about 10 old large cast iron radiators that are all different sizes. Since we don't want to open up more projects such as cutting into the wood floors or plaster ceilings, we are trying to replace the Cast Iron Radiators with Pedestal or Floor Mounted Radiators that are a bit more appealing. The piping to the existing radiators ranges from 6" to 7" from the wall, so going with flat panel wall mounted units is really not an option for us. We are looking to go with a slimmer European style pedestal or floor mounted unit. Myson has some units available, but they are only at specific lengths. (myson decor pedestal). Runtal seems to have a commercial RF3 series that can be floor mounted as well. Wanted to see if anyone knows of any other options out there that are similar in the look and design, and are a pedestal floor mount radiator. Both Myson and Runtal seem to be a bit on the pricey side, and neither would really match up to where the current piping is. Trying to get units that are as close as possible in length so that we don't have pipe exceeding the sides of the radiators ruining the look of them. Appreciate any feedback or suggestions anyone has. Thank you.

Have you considered enclosing them in cabinets or built-ins? Combining radiator disguise with shelving and drawers reclaims wasted space. Ikea sells covers, as do a number of cos that ship them in kits. Google radiator cabinet, radiator cover, built-in radiator cabinet. Dunno that any replacement will work as well as those big ole hunks of iron.

Yeah, we did consider that, but the issue is that some of them are just in the way. Even thought we would still be going with pedestal units, based on the slimmer design they would be 6 inches closer to the wall than these. Some of them are taller than others also, so covering them up would only bring more attention to them. I wouldn't mind them if some were recessed in the wall, but they are all just out and in the way of anything you want to place in front of them.

Radiant floor heating. Covering old cast iron radiators with covers reduces output and raises operating temperatures leading to higher fuel consumption.

We design and install many systems to replace old cast iron radiators with European style wall panel radiators but replace just as many with sub-floor and radiant ceiling panels.

I didn't think there was any fancy temp tuning with the cast iron radiators. You put the heat to 400 pounds of cast iron, which holds it a whole lot better than steel panel radiators, well enough that you can skip the buffer tank. Covering radiators reduces radiant output but convection picks up the slack. you'd have to turn the thermostat higher if it were inside the box. But drop a square of foil faced foam insulation between the radiator and the wall and the btus stay inside the envelope. In a built-in situation, add ductwork and a tiny constant circulation fan.

But I agree with BB's customers: switching to skinnier radiators isn't much of a solution compared to underfloor heat.

A grill type cover box (holes in the entire sides, top and bottom) can't have much effect on convection, but I expect that adding a small (say 5w, 12v) fan would cause to it exceed completely exposed radiator btu output and efficiency.

With an old boiler, there may be no noticeable effect on efficiency either way.

Posted By toddm on 06 Jun 2013 11:18 AM
I didn't think there was any fancy temp tuning with the cast iron radiators. You put the heat to 400 pounds of cast iron, which holds it a whole lot better than steel panel radiators, well enough that you can skip the buffer tank. Covering radiators reduces radiant output but convection picks up the slack. you'd have to turn the thermostat higher if it were inside the box. But drop a square of foil faced foam insulation between the radiator and the wall and the btus stay inside the envelope. In a built-in situation, add ductwork and a tiny constant circulation fan.

But I agree with BB's customers: switching to skinnier radiators isn't much of a solution compared to underfloor heat.

The mass of the metal is the least of it- the thermal mass is in the WATER.  The specific heat of water is ~9.3x that of iron, so that 400 lbs of cast iron only has the heat capacity of (400/9.3= )  43lbs, or about (43/8.34=) ~5 gallons of water.  Most 400lb c.i. radiators will have quite a bit more thermal mass in the water than in the iron, and not dramatically more thermal mass than steel panel radiators of equal volume.

Steel panel radiators usually have better convective transfer (by design) than the column or tube type cast iron radiators, but not necessarily better than the narrow profile flat-faced Sunrad or similar. Covering a column or tube type radiator DOES reduce it's output, and rare is the cover that really looks much better than a cleaned-up & re-painted old-school radiator.

We will be removing custom cast iron radiator covers on a job here in Minneapolis. I calculated the output at half of the uncovered radiator. The rooms get cold in winter. Most covers reduce convection considerably but these wooden solid oak mission style covered fully 75% and without openings bottom or top.

Covering cast iron radiators will always diminish output and reduce system efficiency. Laying a slab of marble or wood on top is not a problem.

By a rule of thumb of 1.5 pints of water per square foot of equivalent direct radiation, a largish old school radiator (5 tubes) would have about a gallon of water in it. A modern finned radiator of equivalent heat output would have not quite half as much. So not only does cast iron trump steel panel in mass, it has more water in it as well. Ergo,to reduce on-off-on-off, go old school. And cover it if you so desire.

Cover if you still don't know any better.

Thanks everyone for all the feedback. I'm second guessing my decision to replace the cast iron radiators with new slim ones from Runtal or Myson and seriously considering either refinishing them or getting covers that would improve the look, but not greatly reduce the efficiency of the radiators.

BadgerBoiler ... in case i do end up swapping them out ... how would one go about getting from

http://www.flickr.com/photos/11678721@N02/sets/72157633978111867/

to something similar to what you posted on your site:
http://www.badgerboilerservice.com/images/radiators_LRrad_Genoa.jpg

Would it be extremely difficult and costly to have a professional move the supply/return lines closer to the wall and pipe into a wall panel unit? I would like to keep the wood floor damage to a minimum.

Thanks again everyone, really appreciate the feedback.

I think the old ones look better. But I'd also consider in-wall fan coils in some cases. Then all you see is a grill on the wall.

Those are some of the nicest looking Old Style Column radiators I have scene in some time. The output of cast iron radiators is easily determined by the using charts available for each style of radiator, matching the style with height, number of tubes and sections. Once the square footage is determined a multiplier is used to determine the potential output of each unit. The multipliers readily available are for steam and hot water to 180°F.

I have not seen a Old Style radiator operate at a 180° EWT in the last 40 years. More likely less than 150°F. This is why old radiators make perfect heating systems when matched up to a condensing boiler.

Now for getting rid of a nearly perfect radiant emitter without suffering unintended consequences. Since the bulk of our business here in Minneapolis is consulting on various heating a cooling systems, we are often asked to remove these fine old eye-sores. Face it, some are prettier than others. The first step is finding out what they do, by noting the high operating temperature during the coldest days of the year and verifying the heat load in each room. From this information a new wall-hung panel radiator can be sized.

As for installation. Much depends on access from below. If the foundation wall is not too wide, you may be able to serve the radiator from below. We regularly serve these our panel radiators from outside walls as PEX can freeze without damage if properly installed. An unlikely event if the proper controls are employed.

Fan-coils are not radiant heating, but forced-air. The antithesis of comfort and economy. We only use a toe-kick or wall-mounted hydronic fan-coil when are customer agrees that neither one of us cares about comfort, in the application we reluctantly specify them for.

Try sitting near a small radiant heat source where part of your body is shaded from it. In this case, I find it obnoxiously uncomfortable as compared to forced air.

Very little irks me as much as when some interior designer or subdivision HVAC designer recommends getting rid of lovely old rads for scorched air so i go out of my way to rescue every one I can find before they go to the scrappy. The worst case of this is when I was called in to do the heating in a 120 year old 5000ft2 house formerly owned by a song writer named Gordon Lightfoot. I had never seen anything like the rads in this house and I am sure they were custom designed and they should be in a museum. The interior designer over ruled me and without my knowledge they met the sledge hammer. I'm sure they would have been worth $3-4k each in the right market. Brought tears to my eyes.

To the OP, KEEP THEM.

I knew there was something I liked about you Mike.

Wasn't the Edmund Fitzgerald carrying scrap radiators?

A handy cast-iron radiator sizing guide lives here, complete with a linear approximation curve for output across temperature. 

BadgerBoilerMN has it right-  it's a very rare situation to find an old-school radiation system that won't run at low temp, since they were typically over-sized for the original heat load, when the house had no insulation, single-pane windows, and leaked air like a sieve.

Old radiators can clean up pretty nicely- even really rusty-crusty ones can, with a touch of sand-blasting. I've seen some really nice bake-on re-finished radiators done on the super-cheap at an auto-body shop, using the leftovers of a whole-car job, when the exact color didn't matter much.  Using automotive paints with clear-coat top finishes you can pretty much get your pick of designer colors, if you're trying to make it fit with a particular look. High-gloss finishes also clean up easier when they get dirty too, but eggshell finishes can too.

Yes. Here in Minneapolis/St.Paul we remove a lot of old radiators and sometimes we even get put them back, sand blasted, primed, painted any color and returned for another hundred years of service. Try that with fin-tube...

Thanks Badger, I've been known to sandblast the rads and apply an opaque colouring stain over them. Beeeutiful. There is a lot you can do with them and one of the great things about them is they WILL last 200 years if you want them to so the long term cost is quite low. Copper fin won't do that, i'm sure.