replacing iron pipe with copper

David Bodner

Sometime maybe 10 or 20 years ago my 1930 house got a brand new WM boiler with a Taco pump stitched into the old system. Forgive my ignorance, but I believe it's a 2-pipe, parallel system. Two sets of large 3-inch or so iron pipes running around the basement, feeding a bunch of smaller iron pipes going into the living areas. But feeding the 3-inch iron is about 3 feet of 1-inch copper coming from the "new" boiler. Things seem to work reasonably well. Lower floors are warmer than upper floors, but that may be a function of the poor insulation in the walls.

Here's my question. I'd like to tear out the large iron pipes in the basement and replace with the 1-inch copper to get back some headroom. I figure since I got the copper feeding the system from the boiler, I can't be making things any worse. Is this a really bad idea?

Also, the old pipes seem to have been installed real carefully, seemingly to allow all water to drain back into the boiler. I guess that's because there originally was no pump. Since I have a pump now, do I have to be so careful about "drainage?" Thanks in advance for your advice.

Dave

Ken D.

Iron

Dave, the system originally was most likely steam or possibly gravity hot water although I doubt it. Replacing with copper is not a bad idea as there is a large volume of water in those iron pipes that you really don't have to heat. Just be sure you size the new piping to handle the flow to the radiators and it is piped properly with the needed flow devices included. Drainage is not critical at this stage, although be sure to think about facilitating the bleeding of air as you pipe it.

Ken_8

You have an old gravity system

Which, to this day is considered the best wet heat there ever was.

Once the coal boiler was pulled and whatever transpired since is obvious. A pumped system replaced the gravity one and the near boiler piping properly reduced to smaller diameter piping - by virtue of the added circulator.

Unfortunately, the design principals for gravity are different than pumped systems and the system balance (as already noted in your comment that the first floor is warmer than the second) was unlikely in the original design.

It is likely that each radiator has an orifice and/or control valve to adjust flow to each. Eliminating all the oversized pipe will exacerbate the imbalance you already see and a lot more than just a simple repipe in copper will be needed to balance the radiator outputs.

In other words, you just can't remove all the 3" steel pipe and run a bunch of 1 or 3/4" copper tube off some manifold or zoned form. You will have to find out if you have orifices, special fittings and/or flow regulators and include that "strategy" into your final plan.

This is not rocket science - but it does require some careful planning or the system will be out of whack balance-wise - and not by just a degree or two!

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David Bodner

Iron to copper

I think you're right about it having been gravity hot water. Don't think it's steam, because the return lines look as old as the supply lines. The system's built with "Erskine Copper Radiators" set nearly flush into the wall. They look like an early version of finned copper tube folded on itself. If I'm doing calculations, do I pretend they're regular finned copper tubing of a similar length (when "unfolded")? Can't find anything that looks like a flow regulator. I guess I'll have to be a bit more cautious before I have fun with destruction. Thanks for your help.

Ken_8

Post a picture of a radiator or

better yet, buy Dan's book, "EDR" (Every Darn Radiator) and see what you have.

If you post a picture, along with some measurements, we can nail it down for you.



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David Bodner

Just ordered EDR

and one more, but here are pictures, anyway. The finned sections are 5" by 30". The open area is normally covered with a heavy steel cover that's open at the bottom and has large slats at the top. I'm guessing in 1930 this was considered to be slightly more elegant (and more expensive) than standard radiators, but a bit less efficient. The house is concrete block construction (fireproof!) with a brick veneer. The radiators are housed in voids in the block wall, probably with just the brick on the outside.

Steamhead

I don't think the Erskines

are in E.D.R., but there are many other convector models in there. Just measure height, width and depth of the cabinets and find something with the same dimensions. This will tell you how much radiation (EDR) you have.

It's possible the circulator is not sized correctly. Believe it or not, this can make quite a difference. When you find out how much EDR you have, go to:

http://www.heatinghelp.com/newsletter.cfm?Id=125

and see how much flow you need in gallons per minute. Then tell us what circ you have and if you can't find a performance chart for it, we can let you know if it's the right one for your system.

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Ken_8

Hey Steamhead,

Is it a converted steam system or converted gravity system?

I've never seen a convector used in any gravity system. That sure doen't mean it can't be done - but the small tube arrangement in a horizontal layout would be very limiting in a gravity system. Since I play with mostly old stuff, I'm surprised that that form of gravity ever worked.

Could it not be a steam system - perhaps two piper - converted to water?



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Dean_7

Iron pipe for copper

Do This before you do anything, #1 buy The lost Art of Steam Heating, #2 buy EDR and READ them both, #3 listen to the professionals on this site .

Mike T., Swampeast MO

Are all the recessed spaces that tall? Almost looks like the convector in that bath is a replacement of an earlier standing iron rad.

Joe_30

Yep, we have very similar 4 1/2 inch deep convectors , 30 inches long. Each has 2 1/2 inch tubes, and aluminum fins. They are buried in the wall. There is a register grate at floor and one at waist level. The convector is about 5 inches off the floor, out of sight. So, yes, there is a big space in there which must promote convection. Of course, there is almost no insulation, just some 1940 tin foil and 1/16 of asbestos. I'd hate to see an infrared of the house.

Am putting in iron rads, and putting 2 inches of good foam insulation in there first.

Mike T., Swampeast MO

A reflector on top of the insulation would be a good idea as well. Some places have foil-faced rigid insulation. If you can't find you can use something like thin aluminum or even mylar (available in rolls at craft stores).

ERNIEB19

COPPER PIPES SIZE !

HI, i HAVE ABOUT THE SAME QUESTION, BUT INSTED OF WANTING TO REPLACE 2" BY 1" I WOULD LIKE TO REPLACE THE  RETURN IRON PIPE  WITH 1-1/4 COPPER, AND PLACE IT CLOSED TO THE CEILING, IT IS NOW LOW ABOUT 63 " OF THE GROWND i DO HAVE SPACE FOR A NOTHER 12" HIGHER, i NOW IT MUST HAVE A PITCH,

Will not replace any other pipes, just the one ,the return my cast iron radiators it's one pipe heating system .

any ideas ?

Thank you.

Ernieb19

nicholas bonham-carter

Steam or hot water?

It would be better to repost this in the steam section (if steam), then you will get more replies, as your question is not buried in a 9-year old thread.

Any repiping of a steam system will have to be done very carefully, and there will some experimentation in the process. An expert steam professional should do it for you, during a warmer time of the year.--NBC

Take some pictures of the layout.