resizing cast iron radiator
measuretwice
| Posted in Energy, Heating & Insulation on
I’m considering resizing some old cast-iron radiators — removing some sections. Looking for info — is it practical? If so, are there any tricks to it? Method and materials to reseal, etc.
Replies
Woody,
Just playing the devil's advocate here, but why are you considering resizing old cast iron radiators? What type of boiler do you have?
Old steam/radator heating systems are something that very few people, including most heating and plumbing contractors, understand well or completely. One that is set up properly and working well is best left alone.
Is it practcal? No.
Are there tricks? Just engineering, no tricks.
Tim
go to http://www.heatinghelp.com and ask them (steam experts).
The re-sizing of radiators can be done, but requires some special nipples be used so that you can re-seal the joints (even though they look like they can be just unbolted and rebolted there's more to it, on the inside).
Depending on the maker of your radiator the nipple is a little different.
I am sure that they can help you!
Hate to hijack a thread, but........
I tore the cast iron system out of our house a few years back. Gave the radiators away. The other day I saw one at a flea market with a sign on it saying "$300 OBO".
Are those things really worth that much?Experience varies directly with equipment ruined.
Only if you want one.
If you want one you need one. Need =$$$.
Sometimes you need one to match for an addition, sometimes you are remodeling and need a different size.
Search for 6 months and $300 will seem cheap, but the radiator would have to be special, and you would have to be anal.
Flip side, try to sell one...
Thanks for your advice & the excellent link! I was trying to figure some of this out the other day -- half the Monoflows in the system I inherited are backwards.
used to see it done all the time....as steam heat moves toward forced heat.....
has probably become a speciality here.....I'd have to find an old plumber!
I'd fine a guy that's done it before and pay to get it done quick......have no idea how involved a job it is myself.
JeffBuck Construction Pittsburgh,PA
Fine Carpentery.....While U Waite
Thanks for your advice Tim. We have a fairly new Weil-McLain "boiler" (it's actually a hot water system). Reason I want to resize: after we thoroughly insulated our balloon-framed 2-story 1880's era house plus installed new high-e doublepane windows, many radiators are WAAAAAAYYY too big.
I had a very competent H/AC guy do a heat loss analysis to quantify what I knew intuitively: uneven heat distribution, too much heat at once, and poor energy efficiency of the boiler. Cycling on & off all the time, burning out igniters. Plus we'd like to gain the space: a 24-section radiator takes up a lot of a room!
Obviously there are some folks out there that know more about reconfiguring these things than I do.
My main concern was with a steam system, the size of the boiler and the condensing (SDR) area of the system is (or should be) balanced. Changing the size of the boiler or the size of the radiation elements independent of the other is a recepie for troublesome operation. Hot water systems are much more forgiving, but the boiler should be sized to match the load.
Makes sense to resize. Did you downsize the new boiler? The efficiency of the boiler will depend more on how it is sized for the load than how the radiators are sized.
BTW you can set up the system to heat with the radiators you have by creating a primary loop at the boiler, a secondary loop for the heat loads and installing a 3-way valve to regulate the secondary loop temperature. Instead of supplying 180 degree water to the loads you could supply 160 or 140. The boiler sees a constant flow and fires when necessary. The 3-way valve will recirculate more or less return water back to the supply depending on the load. But this wouldn't help regaining some floor space.