radiator type vs. square footage

Brad White_203

The style itself does not matter, but each has it's own specific EDR rating per section.

There is some commonality between manufacturers, certain sections of a given height and tube number often are the same across several makes.

Regardless, it is important to get a handle on what each radiator is worth in EDR.

When you select the boiler, it is THIS number which you seek to match in the "Net I=B=R Square Feet EDR" rating.

That number is already "net", meaning that the 33% factor has already been deducted.

If you DO add 33%, then you would seek to match the "Gross Output" number. However, that is usually expressed in BTUs per Hour or MBH (thousands of BTUs per Hour), so you can easily cross your units.

By the way, each EDR is worth 240 BTUs per hour when 215 degrees in a 70 degree room. That is the standard. Use it if you must convert.

But start with the radiators and know them well.

Dan's book "EDR" is a ready reference among others.

Jim_169

radiator sizing charts

I am getting quotes for a new steam boiler. How important is the type of radiator versus just how many secions and how many tubes and height. I know that there are different styles where the tubes are thicker/thinner.

Is this something the calculations should take into effect. Is there a table out there to be used that everyone agrees on? Also, as I understand the final number should be adjusted up by 33% to account for piping loss and such. Thanks for the info

Jim_169

I found a chart that talks about tube type, thin tube etc, which has quite different values based on width. That is what I meant by "style". Is that important or is there just one value I can use for any 5 tube radiator section of a given heighth?

Brad White_203

Things to consider

Some things to consider are the style, whether column, oval tube, large tube or small tube, the center to center section spacing (1.5", 1.75", 2.25", 2.5" being common).

A five tube Burnham Slenderized is less output than a five tube Corto.

Jack_44

resources here

Jim, you can find a great deal of info in the Library and in the excerpts of Dan Holohan's books in the Online Store.

I (as a homeowner) STRONGLY recommend The Lost Art of Steam Heat and Every Darn Radiator as references to have at hand. My experience is that the pros refer to these texts. You can also weed out some hacks by merely invoking the reference.

If you don't want to spend the money for LAOSH and EDR (although once you do, you'll be glad you did), at least buy the We Got Steam Heat volume. Unless you're lucky enough to connect with a real pro (many are here), you'll need the help within DH's books and the postings here.

Good luck.