Unidentifiable Steam Fin Tube

Dmendy1

Hello all,

I am in the midst of reviewing an admin / university building and we are looking into the viability of a Steam to Low Temp HW conversion.

One of the major items we are trying to identify is performance data on all the Fin Tubes that are present in the stair cases and within office spaces. I know this is a shot in the dark but at this point we are trying anything we can to try and identify them because based on the photos I have provided I cant seem to dig anything up on these guys. If anyone is able to provide any sort of data or a point in the right direction it would be a great help.

Link to Photos: https://tfg.egnyte.com/dl/ZraybU2KX3

EdTheHeaterMan

look here https://www.sterlingheat.com/LiteratureLibrary

you may need to page thru the catalogue to find something close. this one looks like it may be close.. But that was only 2 minutes of browsing. You may find something closer to your actual recessed wall convector.

Jamie Hall

I can't tell you what they are, and the way they are slanted in the enclosure is a little odd, but if you can't find anything else you can come within 10% or so of the "exact" figure rather simply. Get the area in square feet of one fin -- count both sides, but subtract for the area lost to the pipe. Count the number of fins per foot -- and that will be your EDR per foot, close enough.

There are tables to derate the output for lower temperatures. I would use the tables suitable for baseboard units, if you can. It would be nice to suppose that the output drops linearly with temperature, and it does -- more or less -- at high temperatures. But at lower temperatures it drops faster than a linear rate. Here's Slant/Fin's chart https://www.slantfin.com/images/stories/Technical-Literature/ratings_fineline30_r.pdf

EdTheHeaterMan

here is the document I got the cut sheet from. This has more specifications. https://www.literature.mestek.com/dms/Sterling Commercial Hydronics/Cabinet Unit Heaters/Model-RW.pdf
But this indicates the cabinet has a fan within the enclosure. Not the same as your heaters... But I believe there is one that does not have a fan, You just need to take the time to look thru all the documents.

Hope this helps.

EdTheHeaterMan

This catalogue may get you close. try to select one that has a similar depth, width and cabinet hight. https://www.literature.mestek.com/dms/Sterling Commercial Hydronics/Convector/CC-14R1.pdf

The convection current air flow is the major factor. The fact the the element is horizontal and not on an angle will have little impact on the performance.

Look at BTU output based on the water temperature. Changing from steam to a lower temperature water will have an impact on performance. But you already know that!

bburd

In general, converting old steam systems to hot water is problematic. Aside from the reduced heat output, hot water systems operate at much higher static pressures than steam systems do, so leakage is likely.

Jamie Hall

bburd said:

In general, converting old steam systems to hot water is problematic. Aside from the reduced heat output, hot water systems operate at much higher static pressures than steam systems do, so leakage is likely.

I wasn't going to mention that. In fact, though, it's highly unlikely that the proposed change will work without significant changes in the radiation, not to mention all the piping. Further, unless the client is also proposing to go to ground source heat pumps as their energy source, they will not save any energy or money (the capital cost of the heat pumps would be eye watering, but the running costs should be lower).

Jamie Hall

I'v sent you a PM, @Dmendy1 , with a source for much more information on your overall project. If your client is really serious about this, two recommendations: start from the top down (what is it you really want to do?) rather than the bottom up (will this convector work?) and get in touch with people who have actually done it. There's far more involved in this than just wondering about convectors and pipes.