Does this look like a 46.8 ft² EDR radiator to you?

Hap_Hazzard

It's a 14" 4-column 40-section radiator, measuring 14.2″ tall, 92.8″ long and 5.5″ deep. The manufacturer says the EDR is 46.8 ft², but, compared to my other radiators, it seems to put out more heat than I expected. It seems to put out at least as much heat as my 6-column 24-section 25" Arco, which is rated at 70 ft².

Ironman

The output will vary depending upon the venting.

Dan_NJ

Looking at the Smithfield EDR estimator there isn't even a value for 4 column 14" height. Seems like if columns this should be around 2.25 sq ft per section making it around 90 sq ft total. Castrads literature shows what appear to be tube and columnar style (or equivalent) radiators? I can't really tell which type this one should be, I know they describe columns but not sure where the line is between column and tube.

Hap_Hazzard

Compared to the Arcos it looks like a column type radiator. You can stick your hand all the way in between the sections. 90 actually seems like a more reasonable estimate.

Re. venting, it takes a little longer to fill than the rest of the radiators due to its size and being the last radiator on its main branch.

bburd

46.2 my eye. What a monster!

Steamhead

That's a large-tube radiator, not a column one. Use the tables for the American Corto or National Aero or similar units.

Hap_Hazzard

I need to find someone who made a 14" window radiator with only 4 tubes. Most of the large tube window radiators seem to be 7 tubes. I'll keep looking.

Steamhead

Is there a name on it? Look at the ends where the pipes connect.

Hap_Hazzard

I know who made it. It's a Castrads Mercury. The trouble is the rating they provided (46.8) seems unbelievably low.

https://www.castrads.com/us/product/mercury-4-column-14in-40-sections

dabrakeman

Best I could do is extrapolation. From a 20" 4 tube 2.25sqft from a 1965 catalogue you could estimate ~1.75sqft per section for the 14" which would put it around 70sqft. Extrapolating a couple other ways from the Smithfield catalog I get 1.5-1.6sqft per section. If settle on ~1.65sqft would get 66sqft for the 40 sections. Surprises me we can't find a 14" 4 tube because under window radiators seemed quite common.
I went through 8 different sources and couldn't find this one. Maybe Hap_Hazard will have more luck.

Big Ed_4

I would say it is big enough

Hap_Hazzard

dabrakeman said:

Best I could do is extrapolation. From a 20" 4 tube 2.25sqft from a 1965 catalogue you could estimate ~1.75sqft per section for the 14" which would put it around 70sqft. Extrapolating a couple other ways from the Smithfield catalog I get 1.5-1.6sqft per section. If settle on ~1.65sqft would get 66sqft for the 40 sections. Surprises me we can't find a 14" 4 tube because under window radiators seemed quite common.
I went through 8 different sources and couldn't find this one. Maybe Hap_Hazard will have more luck.

I can't find any 14" 4-tube radiators either. 20" seems to be the shortest 4-tube large-tube radiator (except for wall radiators, which are shorter because they don't have legs), and the smallest 14" radiator is 7-tube.

Comparing the EDR/section of 20" and 14" 7-tube window radiators by American and Richardson, there's a roughly 68% reduction. Reducing the EDR/section of their 20" 4-tube radiators by the same factor gives me just a hair over 1 ½ ft²/section.

7-tube 20"    3.667 ft.²/sec
7-tube 14"    2.5 ft.²/sec
4-tube 20"    2.25 ft.²/sec
4-tube 14"    1.534 ft.²/sec

This would make the total output about 61 ft².

Hap_Hazzard

Big Ed_4 said:

I would say it is big enough

It's definitely big enough. At the time, it was the biggest 14" radiator they made, and it fits the space perfectly. I'm glad I didn't wait for the 14" 6-column! The reason it's important to know the EDR is that, currently my total EDR, using the rating provided by Castrads (394 ft²), falls roughly between the the net outputs of two possible replacement boilers (383 and 458 ft²), but, since this is such a big radiator, if the real EDR value is anywhere from 15 to 40 ft² bigger, it would be a nudge towards the higher output boiler.

ratio

Maybe orifice it down to the 46.8 ft² size? It looks like a big ol' radiator. Is one that size necessary for the space?

Hap_Hazzard

ratio said:

Maybe orifice it down to the 46.8 ft² size? It looks like a big ol' radiator. Is one that size necessary for the space?

In retrospect I probably could have gone a few sections smaller, but I wanted it to match the width of the window. Also, to center a smaller radiator, I would have had to move the riser, which would have been difficult.

The radiator this replaced was a big honkin' double-row fin-tube convector with about 68 ft² EDR. It never worked, because the runout was 1" copper with a few bends in it, but I thought the size of the convector might have been based on a heat-loss calculation for the bay window, so, at the time I thought 46.8 might not be enough, but if I could get it to heat all the way across, it would be a big improvement. As it turns out, the output is just about right for the space it's in. The temperature is about the same as the living room, where the thermostat and the largest radiator both reside. I'd just like to know the EDR so I can get an accurate estimate of total radiant load.

kcopp

If its Castrads it maybe a steel radiator made to look like a cast iron one..... that may explain it.

ChrisJ

Hap_Hazzard said:

Big Ed_4 said:

I would say it is big enough

It's definitely big enough. At the time, it was the biggest 14" radiator they made, and it fits the space perfectly. I'm glad I didn't wait for the 14" 6-column! The reason it's important to know the EDR is that, currently my total EDR, using the rating provided by Castrads (394 ft²), falls roughly between the the net outputs of two possible replacement boilers (383 and 458 ft²), but, since this is such a big radiator, if the real EDR value is anywhere from 15 to 40 ft² bigger, it would be a nudge towards the higher output boiler.

Is your current boiler rated for 404sqft and it produces several oz of pressure during a normal heating cycle?

If so I'd go with the 383 without questioning it.

dabrakeman

I guess if you know for a fact that it is a Castrad radiator then not sure why we would question the published edr for it? Mercury 14" 1.2sqft/section or Grace 1.15sqft/section. Who knows, maybe the castings are thinner? I wouldn't oversize the boiler and you can always slow that radiator down with the right vent if the room is too hot.

Steamhead

I'd go with the larger of the two boilers, and downfire it slightly if needed, using a digital analyzer to make sure the combustion is good. This would probably extend its life too, since the cast-iron in the boiler wouldn't run so hot.

Hap_Hazzard

ChrisJ said:

Is your current boiler rated for 404sqft and it produces several oz of pressure during a normal heating cycle?

If so I'd go with the 383 without questioning it.

I've seen it get as high as 3 oz. on a very long run, but I also have a 32 ft² radiator turned off because we aren't using the room very frequently. Also, the boiler was rated at 405 ft² 40 years ago. I'd be astonished if it hadn't lost some capacity over the years.

That said, if I had to do it today, I'd get the 4-burner model, because it's available and less expensive. It's just a question of whether or not I'd spend the $200 to upgrade it right off the bat or wait & see.

Hap_Hazzard

kcopp said:

If its Castrads it maybe a steel radiator made to look like a cast iron one..... that may explain it.

No, it's definitely cast iron. I had to carry it in and assemble it.

Dan_NJ

Hap_Hazzard said:

That said, if I had to do it today, I'd get the 4-burner model, because it's available and less expensive. It's just a question of whether or not I'd spend the $200 to upgrade it right off the bat or wait & see.

By the numbers it looks like you're debating between Peerless 63-04 and 63-04L. If you go with the 63-04L and decide to go higher, maybe we can trade flue collector, burner tray rear support and manifold, and I'll throw in a spare burner tube I could really go down to the 63-04L and be a happier camper.

Hap_Hazzard

Dan_NJ said:

Hap_Hazzard said:

That said, if I had to do it today, I'd get the 4-burner model, because it's available and less expensive. It's just a question of whether or not I'd spend the $200 to upgrade it right off the bat or wait & see.

By the numbers it looks like you're debating between Peerless 63-04 and 63-04L. If you go with the 63-04L and decide to go higher, maybe we can trade flue collector, burner tray rear support and manifold, and I'll throw in a spare burner tube I could really go down to the 63-04L and be a happier camper.

Bearing in mind that it may be years before I need to do this (knock wood), I'd love that. I couldn't help noticing that, based on the prices I've seen, it's about $200 cheaper to buy a 63-04L and the parts needed to upgrade it than to buy a 63-04. If I could get those parts for less—and help out a fellow Wally—so much the better.

If you end up buying the conversion parts in the meantime, hold on to the parts you swap out so I can buy them from you when the time comes.

BTW, have you checked with PB Heat to see if this would impact your warranty coverage? I don't see how it should, but companies can be arbitrary sometimes.

Dan_NJ

I haven't checked into it with PB at all. I'm into season 5 with this one so halfway thru the 10 year general warranty period. I've been on the fence about converting it since I would not be doing it myself. If I go that route I'll definitely keep my 63-04 spares.

Hap_Hazzard

Dan_NJ said:

I haven't checked into it with PB at all. I'm into season 5 with this one so halfway thru the 10 year general warranty period. I've been on the fence about converting it since I would not be doing it myself. If I go that route I'll definitely keep my 63-04 spares.

It doesn't look like a very difficult conversion to me, but I might be a little more "adventurous." You'd want to get a gas man to adjust the gas valve, check the combustion and make sure all your connections are tight, but changing the parts shouldn't be a big deal.

mattmia2

Did you measure and calculate the actual pickup or are you using a rule of thumb pickup factor? Seems like a little smaller would be better unless the heat loss of the house really matches the radiation.

Hap_Hazzard

mattmia2 said:

Did you measure and calculate the actual pickup or are you using a rule of thumb pickup factor? Seems like a little smaller would be better unless the heat loss of the house really matches the radiation.

I'm using the standard pickup factor. This house was built in 1940, between the Great Depression and WWII, so the days of open windows and oversized radiation were over. 22 years of day to day experience also bears that out.

Nick_Castrads

Hi, my name's Nick Baylis and I'm the owner of Castrads.

All our testing is done on hot water by independent test bodies - we usually use BSRIA in the UK.

Here are the test results for the radiator in the photo (it's a Mercury 4 Column 14in):



The method we use to convert from Watts at ∆T50 to steam output in BTUs at 215ºF is as follows:

1. Correct output at ∆T50ºC to output at 170ºF MWT (∆T56.7ºC)
2. Convert to BTUs
3. Divide BTU output by 150 to get EDR
4. Multiply EDR by 240 to get steam output at 215ºF steam temperature, 1psig pressure and ambient temperature fo 70ºF.

We also cross reference the calculated EDR against the CAD models for our designs. On our entire range, we found a variance of only about 2% between the CAD models (with surface roughness applied to simulate the cast surface) and the reverse-engineered EDR values from the method outlined above.

We always use actual measured outputs from the test houses for our advertised figures rather than calculated surface area from the CAD models.

reggi

It looks heavier than 250.4 lbs   

reggi

@Nick_Castrads ,
Welcome and thanks for the information 👍 I was wondering how the Thermal results compare to the original Manufacturers ratings as I imagine EDR is a fairly standardized... standard 😕 ?
Have you found any or many variations in any Manufacturers ratings with any of the radiators you have had tested vs the original calculation? If so Larger or smaller ?
And one more thing I was wondering is what do you do with all the old inlet valves and return ( Variations) on all those thousands of Radiators you own or buy as some of those are desirable to certain people or do you get the radiators bare for easier transportation... nothing poking out that is..
I do remember a little while back someone representing your company was here looking for Radiator Catalog Sources for something your company was working on.... can't remember exactly what but if I recall he seemed happy with the information so I hope that works out for you...I don't think it was long enough ago that anything but a design or model would of been done but what do I know.. 🤗

tim smith

When I look at a 4 tube corto 28 tall it comes to 3sft per section, so my guess is is 1.5 per section would put it at 60? Would think pretty close.

Nick_Castrads

@reggi thanks for the welcome. Are you based in Rhode Island or Massachusetts? If so, that was probably me coming over. Are we talking back in summer 2018? Do you run a supply house?

On thermal results comparisons, we can compare an ARC Corto to our Mercury. They have a very similar sized column diameter and are essentially the same geometry save some minor design elements.



The Corto 4C26" is advertised at 2.75 sq ft EDR per section.

Based on the BSRIA test results for our Mercury, and corroborated with the CAD data, our EDR for the equivalent size is 2.2 sq ft. N.B. We don't actually make a model at 26" tall but I've interpolated between the 22" and 30" models.

Comparing EDR figures from both the thermal tests at BSRIA and our CAD data, our new models seem to be consistently lower than the EDR figures advertised in the old manufacturers' literature for radiators of equivalent geometry.

You asked about the returned valves - we do offer a refurbishment service in NYC but the larger part of our business is the supply of new cast iron radiators: we create our own designs based largely on the greats that came before us, subcontract the foundry work (we use three foundries - two in the UK and one in Turkey), and then machine, assemble and surface finish at our factory in Manchester, England, before shipping orders to our warehouse in the Brooklyn Army Terminal and from there, we send orders by road across the country.

Hap_Hazzard

Thanks for the detailed response, @Nick_Castrads. I still think you're underrating this radiator's performance though. It really blasts! It could have something to do with the massive amount of convection it generates compared to the rest of my radiators, which are all taller & narrower, but it has made a huge difference in the comfort level of the room, which is much appreciated as my wife uses that room as a home office now.

I'm considering building an enclosure of some sort so I can control the convection, but I hate to do it because it's such a beautiful radiator. I really love it.

Nick_Castrads

@Hap_Hazzard I'm glad it's doing the job! I can't see your valves so I'm not sure what system you're on, but do you have TRVs already? If not, that might be a way to control the heat without covering up the beauty! 

mattmia2

Hap_Hazzard said:

Thanks for the detailed response, @Nick_Castrads. I still think you're underrating this radiator's performance though. It really blasts! It could have something to do with the massive amount of convection it generates compared to the rest of my radiators, which are all taller & narrower, but it has made a huge difference in the comfort level of the room, which is much appreciated as my wife uses that room as a home office now.

I'm considering building an enclosure of some sort so I can control the convection, but I hate to do it because it's such a beautiful radiator. I really love it.

The new radiator may have more mass than the existing radiators so it emits heat for longer after a heating cycle and evens the heat out more.

Hap_Hazzard

mattmia2 said:

The new radiator may have more mass than the existing radiators so it emits heat for longer after a heating cycle and evens the heat out more.

It definitely does that, but all my other radiators are cast iron. This was my main consideration for buying a cast iron radiator instead of trying to fix what was there. Even if I'd gotten it to heat up all the way across, I knew a fin-tube unit wouldn't retain the heat as well. Aside from being lighter, they're expressly designed to dissipate heat quickly. That's not what you need in front of a big bay window like that.