radiators - cast iron vs. aluminum
#1
08-06-08, 07:51 AM
radiators - cast iron vs. aluminum
I have recessed cast iron radiators, and they heat beautifully. However, I am redoing my bathroom and am considering replacing the radiator with one of the new aluminum panel types. Any thoughts on whether or not this is a good idea? I know the BTUs of the new model but don't know what the output is of the existing radiator, do I don't know how to compare.
#2
08-06-08, 08:18 AM
If you have fairly continuous circulation the comfort shouldn't be an issue. Otherwise, the alu will heat like a speedboat and the cast iron will heat like a freight train. That aluminum will be up to temp like a fast boat hitting its planing speed and as soon as you chop the power or hot water flow, it will slow to a crawl much quicker than the freight train.
With continuous circ this isn't really a factor since the changes are gradual - much better just for the comfort alone.
Why not steel instead of aluminum? I'd think the fewer different metals in the mix the better. All stainless would be magnificent if you wanted to pay the crazy price.
With continuous circ this isn't really a factor since the changes are gradual - much better just for the comfort alone.
Why not steel instead of aluminum? I'd think the fewer different metals in the mix the better. All stainless would be magnificent if you wanted to pay the crazy price.
#3
08-06-08, 09:00 AM
There is a thread here from a year or so ago about how to calculate the output of 'unknown' radiators. A guy by the name of HVAC_EMT or something like that led the way.
There's also a book called "EDR: Every Darn Radiator" that may be at a local library, or google it and you can buy a copy. Has output descriptions of many many radiators.
Beyond that, what Who said about the thermal characteristics. Especially in a bathroom where having that nice residual cast-iron mass providing warmth adds to comfort. In an all-cast-iron rad system, I'd suggest keeping the rad. While it's out for renovation, DIY or have it sandblasted and painted.
There's also a book called "EDR: Every Darn Radiator" that may be at a local library, or google it and you can buy a copy. Has output descriptions of many many radiators.
Beyond that, what Who said about the thermal characteristics. Especially in a bathroom where having that nice residual cast-iron mass providing warmth adds to comfort. In an all-cast-iron rad system, I'd suggest keeping the rad. While it's out for renovation, DIY or have it sandblasted and painted.
#4
08-06-08, 09:43 AM
here is a site which tells you how to size the radiator. If the new aluminum is a lot less output you will feel the difference. zzyou will need to scroll down about halfway. The output of the cast iron rads varies slightly but not a whole lot. This generic radiator will get you close.
http://www.comfort-calc.net/Steam%20...ng%20radiators
http://www.comfort-calc.net/Steam%20...ng%20radiators
#5
08-06-08, 10:19 PM
Thank you all for the replies, information, and links. I don't know if we are allowed to mention brands here, so I won't, but I just liked the idea of a sleek new radiator in a new bathroom - actually a 6 panel high baseboard. However, the bathroom is at the beggining of the loop, and is followed by 5 more radiators in the bedrooms. I've always been happy with the system, so I leaning in the direction of leaving the radiator. My little decorative pipe covers are missing at the bottom, but we'll figure something out. A friend wire brushed her radiator, primed it twice, and use the special heat resistant paint on hers. The first time it got hot, all the paint started flaking off. She was told she should have done a final cleaning with alcohol before the paint. I have my fingers crossed.
#6
08-07-08, 04:52 AM
This is an idea that I'm throwing around when I tackle my main bathroom. Scrap the the baseboard all together and free up some wall space. Buy a nice cast iron tube and run a length of copperfinned tube baseboard without the covers along the inside skirt area of the tub. Run that on its own loop with a gate valve so you can throttle the flow to control the temp. You will have a nice warm tube and a large mass to heat the room. Plus score some points when the significant other sits down on a nice warm surface 
John
John
#7
08-07-08, 12:49 PM
As far as painting the cast irun radiation. Clean the radiator, rough it up with some sandpaper, if some primer is gone reprime areas with a latex primer and topcoat with a oil base paint. No need for a high temp paint.
#8
10-02-10, 03:21 PM
Member
Join Date: Jan 2008
Location: Nassau County Long Island
Posts: 1
Upvotes: 0
Received 0 Upvotes
on
0 Posts
I need to replace two hot water cast iron radiators which were destroyed because of freezing pipes last winter. I cannot find where to get something like these except for websites in the UK but shipping would be prohibitive on top of the already expensive price. the radiators are: Weil McClaine circa 1930's four tube x 27 sections x 25 inches high (w/legs) 4.5" thick, 25" high, 46" wide (27 secs) and the other is American Radiator 6 tubes x 24 secs. x 25" high (w/legs). [8" thick, 25" high, 46" wide (24 secs)]actually could fix them if I could get the replacement sections which in both cases are the end section with the legs. handyman already fixed one other radiator because blowout was in the middle of the radiator. removed the section and reconnected. Who can help me find parts or a replacement radiator either used or new? also would panel radiators work as a replacement for these? are there steel or aluminum cast radiators available or adviseable? Anyone got a solution that does not require a Federal Loan? Help needed in Oyster Bay, NY
#9
10-02-10, 03:49 PM
Check craigslist for cheap used ones. No telling if they are good or not. Burnham makes new cast iron radiators. They probably don't look as good as your old ones. Go to their web site and check them out. This place restores them up in MA: Radical Radiator Restorations I'm sure there is a place closer to you that does similar work.
#10
10-02-10, 04:12 PM
I did some searching and found this link: Cast Iron Radiators: Suppliers of Replacement or New Radiators Not anything closer to you but some different resources.
I searched architectural salvage and came up with this list: Good Questions: NYC Architectural Salvage Resources? | Apartment Therapy New York
Even if any of those places don't have what you are looking for, they may be able to point you in the right direction. Your local plumbing supplier should be able to help you get new cast iron rads.
I searched architectural salvage and came up with this list: Good Questions: NYC Architectural Salvage Resources? | Apartment Therapy New York
Even if any of those places don't have what you are looking for, they may be able to point you in the right direction. Your local plumbing supplier should be able to help you get new cast iron rads.
