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# Which EDR factor to use?

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Member Posts: 52
edited December 2021
I have a columnar radiator with 4 tubes, 20" height, 6-1/4" depth, and I'm am trying to determine its EDR. I'm finding different charts provide different factors to use. For example, Chart 1 provides a factor of "4" and that calculates to 76 (4.0 x 19), Chart 2 provides a factor of 2.2 and that calculates to 41.8 (2.2 x 19). What am I doing wrong?

Thanks

Chart 1
Chart 2

• Member Posts: 5,739
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You need to determine what type of radiator it is.  You are looking at two different charts, one for column style rads and the other for tube type, so that’s why you are seeing a difference.

If you post a picture of the radiator we can tell you what type it is, I’m guessing tube type, but the pictures will tell the tail.
2014 Weil Mclain EG-40
Boiler pictures updated 2/21/15
• Member Posts: 52
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I get that part, columnar vs. tubular, but Chart 2 seems to direct me to use tube numbers due to my radiator 6-1/4" depth. In their chart, for 4 columns/tubes, columnar displays 11-1/4" for the width while tubular displays 7", seems to me that I should use tubular, confusing.

Thanks

• Member Posts: 5,739
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The chart doesn’t tell you what type you have, you look at your radiator and determine what type it is then use the appropriate chart.

If you can’t find it in any readily available charts, you may have something unique.  If you post a picture someone can help.
2014 Weil Mclain EG-40
Boiler pictures updated 2/21/15
• Member Posts: 16,843
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Post a pic of the radiator in question.
All Steamed Up, Inc.
Towson, MD, USA
Steam, Vapor & Hot-Water Heating Specialists
Oil & Gas Burner Service
Consulting
• Member Posts: 15,544
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It has to be tubular. You couldn't fit 4 columns in a 6 1/4 " space.

So you should have 2.2 EDR/section
• Member Posts: 7,852
edited December 2021
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The original manufacturer is the only source for determining the actual EDR of a particular radiator section. Since that information is not always available, there are generic charts that will get you close. Look at your radiator and determine if the radiatoris a column that looks like this or a tube that looks like this

Column type resembles the circumference of a 1-1/4 to 1-1/2 diameter pipe, while a tube type looks more like 3/4" pipe diameter

I think the drawings associates with the charts are pretty self explanatory.

Edward Young Retired

After you make that expensive repair and you still have the same problem, What will you check next?

• Member Posts: 2,846
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Just another DIYer | King of Prussia, PA
1983(?) Peerless G-561-W-S | 3" drop header, CG400-1090, VXT-24
• Member Posts: 52
edited December 2021
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I have 4 variations of radiators I find, here's their photos:

a) Living Room
Height 20; Depth 6-1/4

b) Dining Room
Height 32; Depth 5-5/8

c) Bath
Height 19-1/2; Depth 4-1/2

d) Bed Rooms
Height 26; Depth 4-1/2

Thanks!

• Member Posts: 16,843
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Those look like small-tube radiators. Use the Burnham Slenderized chart in "E.D.R.".
All Steamed Up, Inc.
Towson, MD, USA
Steam, Vapor & Hot-Water Heating Specialists
Oil & Gas Burner Service
Consulting
• Member Posts: 2,846
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Crane still makes and sells cast iron radiators in the UK.

Their designs seem to have changed a little, but I'm not sure if or how much this affects the output. You might try contacting them to see if they have ratings for the old radiators.
Just another DIYer | King of Prussia, PA
1983(?) Peerless G-561-W-S | 3" drop header, CG400-1090, VXT-24
• Member Posts: 2,846
edited December 2021
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Just another DIYer | King of Prussia, PA
1983(?) Peerless G-561-W-S | 3" drop header, CG400-1090, VXT-24
• Member Posts: 52
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Those look like small-tube radiators. Use the Burnham Slenderized chart in "E.D.R.".

@Steamhead, I checked the Burnham section on page 190, it doesn't match up to what appears to be Crane radiators I have, ugh.
• Member Posts: 2,846
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Your dining room radiator looks like a slenderized radiator, so it should be similar to the Burnham slenderized. Your Crane radiators should be similar to a tube radiator like an American Corto, Richardson, Weil-McLain Cameo, etc.
Just another DIYer | King of Prussia, PA
1983(?) Peerless G-561-W-S | 3" drop header, CG400-1090, VXT-24
• Member Posts: 15,544
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@ranzerox

Use the thin tube ratings by Burnham or Weil Mclain. If its not exact it will be fine. Some of the old stuff is hard to find.

You pick a chunk of cast iron about the same dimensions as what you have and go with it