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Steamhead

for water temp of 160 degrees and air temp of 70 degrees F.

Also note that they give different outputs based on how many fins per foot of fin-tube (24, 32 or 48). Make sure you have the right number.

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S Ebels

Convector cabinet?

Anyone know where I can find info on btu output @ varying water temps for cabinet style convectors? The ones I looked at are 1 1/4" steel pipe with heavy fins that measure roughly 5" square. Each cabinet has a double row of these in it, one on the bottom about 12" off the floor and the other row at the top of the cabinet which is roughly 30" from floor.

Thanks

Dave Yates (PAH)

www.burnham.com

in the heating helper book

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S Ebels

OK, I dug out the Heating helper and

I'm trying to understand the corelation between btu's and sq.ft. The pictures on page 43 show similar style convector cabinets except the ones I'm looking at have 2 heavy duty fin tube sections in each cabinet, one at the bottom and one at the top. It is very heavy steel fin with 1 1/4" steel pipe in the center. If I have to guess, I'd say that the output would be closer to the copper typr than the cast iron type.

So now I go back to pg 22 where it converts steam sq ft to hot water btu's (I think?). Do I use the column for 1 1/4" pipe, which is the size in the cabinet, or do I use the pipe size actually feeding the cabinet, which varies from 1/2" to 1" depending on the length?

So, if I have a cabinet that's 4 1/4" by 24" by 48 1/2", the chart tells me that I have 34.2 sq ft of radiation. Going back to page 22 with the steam to water conversion table, it shows that at 160* and 1 1/4" pipe, each sq ft is worth 1231 btu's(?) for a total of 40,800 btu's. This would be a total of 40,800 btu's from that 48" cabinet.

My gut level instinct tells me there's no way to get that much heat from a cabinet that size. Maybe I'm wrong, I remember a time or two that I have been, and when I forget those, management is always kind enough to remind me.

J.C.A._3

One other factor.....

You can only get so many btu's through certain size pipe!!! The smaller feeds will give you less BTU's/ft than the larger feeds.

Methink's you are up against a flow factor, as opposed to an output number per unit factor. (it's in the same book thankfully!) Chris

jeff_51

yes the btu's will be limited to the supply size

and that is all you'll get regardless of the convector output. I can't find my handydandy b&g pocket card, but if I remember right, a 1/2 inch line will carry 20,000, 3/4 will carry 40,000 and 1inch will carry ? I guess I don't remember that one, prolly 80,000

EBEBRATT-Ed

A square ft. of hot water radiation is usually 150 btu/sq ft.

As far as the pipe feeding the convector 1/2" 15000 btu, 3/4 40000, 1" 80000, 1 1/4 16000 With a 20 deg drop in water temp.

Ed

Steamhead

Steve, who made these convectors?

They sound like Dunhams. I don't know of anyone else who made floor-standing convectors with 1-1/4" elements. If so, I have some old catalog info- let me know.

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S Ebels

What water temp?

S Ebels

???

Can't tell you Frank. I looked them over inside and out and there wasn't a tag or name anywhere. About 8 layers of paint. They look like the cabinets in Burnham's little book, but the elements are more like you'd find in modern commercial slope top cabinets. Steel pipe wrapped in heavy gauge steel fin. All the cabinets have manual dampers.

Steamhead

This might help

From the 1953 Dunham Product Application Manual. Some of Dunham's commercial-type radiation has dimensions similar to ordinary convectors, and they do use 1-1/4" finned elements. Use the two-tier part of the table. There's also a table of correction factors for different room and water temps.

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S Ebels

Frank

I can't quite read the chart for the conversion factors. What does it call for with 160* water temp? When I blow up the image it just gets more blurred.

These look like a very close approximation of what is in the building if not the esact thing.

Thanks

S Ebels

Thanks Frank

I noticed the fins/ft on the chart. Never paid any attention to that because I didn't realize they came in different configurations. Probably have to go back and count. Thanks again.