EDR Calculation Check

bigsteamedp · August 2017

Hi,
I'm looking to replace my boiler. Current is an HB SMITH 6 Section boiler nameplate says 1290 Sq Ft Steam and 309,100 BTU. But it's got a conversion unit attached so this is questionable I guess.

I've attached an excell sheet with all the calcs for EDR of the radiators (2 pipe system). Does anyone care to comment on my totals? I came up with a total EDR of 993 and DOE of 317000.

I think my current boiler is sized correctly, great! Estimates I've gotten suggest I should go with a Burnham IN11.

Just looking for any thoughts or checking of my work.

Thanks in advance.

KC_Jones · August 2017

For calculating boiler size you take your square foot calculation and compare that directly to the square foot rating on the boiler, don't add the pick up to that or you will oversize. So if you are at 992 you compare that to 1290 of your current boiler and you are 30% over sized.

I suspect some of your sizes are off. At least two stand out to me. You have a rad that is 16" tall 2.5" deep, but you say it's 15 sq ft per section? That sounds really high to me. Another at 30" tall, 3.5" deep and 10 sq ft per section. I can't see these rads, but those dimensions and that sq ft seem way off. Pictures may help clear it up.

Steamhead · August 2017

What @KC_Jones said. There are enough different radiators out there that we'd need to see them to verify their capacities. Post some pics and we'll have a look.

Also, where are you located?

bigsteamedp · August 2017

Thanks for the replies. Here's a couple of pics of my big rads, they are BIG. One I can't take a good pic (office in my file) but it takes up almost a whole wall. The one long rad is on the ceiling in my basement (hobbit room in my file). The other I have two pics below is of a rad that works on convection heating a large space above in my living room. I'm in Worcester, Ma.

bigsteamedp · August 2017

Second try on the pics

Dave0176 · August 2017

I'd recommend two Weil McLain EG-55s rated at 521 sq ft steam each, that way you could modulate both of them.

bigsteamedp · August 2017

That sounds like an interesting plan, I will ask about it as I get quotes. my guess is nobody is going to want to do that though it's probably too complicated

KC_Jones · August 2017

You had an offer from a great steam guy on here @Charlie from wmass on one of your other posts. Have you called him for a quote?

https://heatinghelp.com/find-a-contractor/detail/charles-garrity-plumbing-and-heating

bigsteamedp · August 2017

I've contacted him, yes, multiple times. Unfortunately we have not been able to connect to obtain a quote. I've heard great things about his work.

Charlie from wmass · August 2017

One would be better off splitting the boilers unevenly. This way you could have the larger boiler match the heat load of the building and the smaller one work for the pickup Factor and initial startup. Be warned that hooking in multiple Steam boilers to a single system requires proper piping more than any other system.

bigsteamedp · August 2017

@Charlie from wmass, left you a VM. Talk soon.

EDR Calculation Check

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