Really dumb question about steam boiler sizing. Burnham Megasteam options.

SteamingPile

I have a decent sized house ... 3000+ sq ft. I outlined the # of radiators and the EDR in another thread, but it worked out to 351 sq ft.

I currently have a 713 sq ft late 60's early 70's American Standard steam boiler so it was almost exactly 100% oversized.

I'm looking at the Burnham Megasteam boilers. I think the MST396 would probably be a great replacement should I go that route.

My question is this.. What is the market for the larger models? When my radiators are cranking it heats the 3000 sq ft really nicely. I see Burham has a 513 and 629 sq ft option. Are these palaces?

Steamhead

Sure you got the EDR right? That sounds a bit small for a house that size................

SteamingPile

Steamhead said:

Sure you got the EDR right? That sounds a bit small for a house that size................

I should elaborate a bit... 11 radiators total for 2 floors plus a finished unheated walk-up attic equaling over 3000 sq ft. There is also a large 2nd floor master bedroom (15x25ft) which has baseboard electric heat.

Since all that heat is rising it's quite comfortable in the attic. I also have a wood stove insert cranking most nights which helps quite a bit.

11 radiators of varying types:
40 sq ft hallway
50 sq ft big kitchen
34 sq ft small sitting room
34 sq ft kid bedroom 1
37 sq ft kid bedroom 2
27 sq ft 2nd floor full bath
34 sq ft upstairs office
16 sq ft small 1/2 bath
24 sq ft living room A
24 sq ft living room B
34 sq ft small 1st floor bed

ChrisJ

Mine are oversized but I've got 392 sqft and the house is 1616sqft

Steamhead

I would double-check those figures. Also include enough capacity to put a radiator in the master bedroom- it'll be much less expensive to heat that with steam as opposed to electricity. Do a heat loss on the space and convert it to EDR.

JohnNY

I figure in exposed risers to my EDR calculations. Individually, they're small numbers but they add up.

nicholas bonham-carter

Is this system one-pipe or two?--NBC

SteamingPile

one pipe.

The master isn't part of the original main house so there isn't a straight vertical run get a radiator in there. I'll have to go into the crawl space and double check.

They added the electric baseboard before we moved in. I may install a 3 zone mini split in the summer for the 3 upstairs bedrooms.

I'll double check the EDR #s.