Identify this radiator heating element and baseboard convector enclosure

ariccio

I'm trying to get a little bit more precise EDR estimations for this building.

Nearly every radiator in this building has this same heating element in different lengths. It's some kind of iron or steel, and enclosed in a kind of baseboard cover that looks like it's intended to be a convector:

Ignore the fiberglass (temporary) and the extremely ugly caulking (I just didn't even care about appearance there 🤣).

They're really old, probably original to the building. But I don't see anything like them in the dunham catalog - the closest is the OTS element, but that only has one "row", and many of these have three.

If I use a generic recommendation for calculating EDR (3.4/ft), round it up (4/ft), assume the largest size that fits (5ft), multiply the result by the rough number of radiators (4x5x400=8,000), convert to BTU (8,000x240=1,920,000), increase by 25% for pickup factor (2400000), I end up with a number that's nearly double half (1.895) the net steam output of what the co-op installed.

I always try to solve for answers that assume correctness by other people, well intentioned people, people who I'd like to believe did the math correctly... But I also know they installed a boiler that has an even larger firing rate (and presumably, net rating due to efficiency improvements over 60 years) than the original boiler from 1960 when there were single pane windows. So, something doesn't add up, I just want to be able to better quantify that amount of "not adding up" more before asking around.☺️👍

I know that there's much I don't know, and now that I've collected so much thermocouple data the next step towards getting me closer to matching their calculations is knowing the upper bounds of the radiation we have.

I suspect I'm actually overestimating, since some portion of the 400 radiators are cabinet style connectors with only like 2ft of radiating element... Which, all the more surprising to see something so oversized!

Edit: Meant to say EDR is half the size of the boiler

delcrossv

What's with the hose clamp? 😬

bburd

Since this is a steam system and the radiation is original, if I were you I would rely on the firing rate of the original boiler which would have been sized by the engineer who designed the entire system. If you are not changing the radiation, you size a steam boiler for the existing EDR, not the current building heat loss.

Those convectors are probably in the book "EDR: Every Darn Radiator", available from this site.

You could also measure the fins, figure the area (using both sides, so 3" x 4" fins are 24 in.² of radiation or 0.167 sf each), count the number of fins per foot and multiply by the total length of finned element (the enclosures may be longer; only count the finned length) to estimate the net EDR. Multiply by the 1.33 piping and pick up factor, divide by boiler combustion efficiency (0.80ish?) and you have your maximum firing rate.

ariccio

https://forum.heatinghelp.com/discussion/comment/1837139#Comment_1837139

Those are hose clamp thermocouples (see some of my other posts). They're an excellent way to get a consistent and long term temperature reading from a pipe! Slip them on and tighten them down for good contact.

Only downside that I discovered (the hard way) is that they have to be electrically insulated from eachother. So there's at least one layer of thermally-conductive electrically-insulating tape wrapped around the pipe and between the pipe and the thermocouple.

skimmer

Whats on the end of the thermocouple leads?

PeteA

@ariccio

You may be able to find the ratings on these convector elements on the OCS site. They have a data sheet for steam and hydronic outputs for steel or copper elements.

https://ocsind.com/products/convector-elements/

EBEBRATT-Ed

That looks like commercial fin tube. You can also find it with steel elements.

Sterling radiator, Vulcan or Beacon Morris. All owned by Mestek I think

ariccio

https://forum.heatinghelp.com/discussion/comment/1837211#Comment_1837211

The other end? A datalogger lol

ariccio

Looks like you nailed it!!

ariccio

(am I supposed to combine posts on this forum or do y'all prefer triple posting?)

Ok, now things are closer to adding up. If I were to assume every radiator in the building was 48", and zero pickup factor, the EDR almost exactly matches that of the new, larger, boiler. I think I can pick this as an absolute upper bound on the estimate now.

PeteA

@ariccio

If you have multiple posts covering the same topic @Erin Holohan Haskell is the admin/owner of the site and she can combine them to make it easier for you and for others to follow and help

mattmia2

the edr number on the boiler has a 30% pickup factor subtracted from it. if anything you should remove some from your connected load calculations because your piping is likely far less than a 30% load.