For the steam guru's

Brad White_9

Measure your piping and take that into account as EDR including if it is insulated.

If your selected boiler (the 856 SF) is "Net I=B=R" that includes 33% for piping and pick-up. That is your margin of safety. You are off by less than 2%.

If the piping is well insulated and your numbers are net, you are off by only 14 SF. I think that is a nice selection and would leave it alone. Vent well and enjoy.

Of course the assumption is that the radiators are proportional and adequate to the job in the first place; chances are they are that, if not oversized, if history serves.

My $0.02

Tony Viz

For the steam guru's

Big house, about 20 radiators. Did the math and ordered a SGO-8 (856 sq ft) Got it down in the basement and thought "no way is this thing gonna heat this house" Checked my math and came up with 870 sq ft. (must have missed one) So now I'm worried that 1) the boiler is too small and 2)I'm going to have this thing going out on low water all the time. I can still return it and get the next size boiler ( small commercial) What would you do?

Al Letellier_9

sizing the boiler

I agree with the other post that you are probably OK with your selection. You can't take if back if it's already installed, obviously, but you could add a section and get the right jacket if necessary. Easy to do with the Weil boiler.


To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"

Mad Dog_2

I've agonized over a few jobs over the years

when I couldn't get firm edr numbers. These homes had handmade convectors that could not be accessed w/out damaging the walls. The only boiler I ever UNDERSIZED was the first one that went in to my home on the brand new steam system I installed. I wanted to see how close I could play it. The boiler's steaming capacity was exactly the same as the radiator load. If I had used "normal" sized mains (2"), I would have got away with it. However,
I used 2 1/2" mains to keep my system on ounces. This extra piping the boiler had to overcome was just too much. I'll insulate really well, I thought. That didn't really help either. I had to rip her out and go one section bigger. If your numbers are adding up, and you can see everything your trying to heat, I think you'll be fine. Brad gave you sound advice. Mad Dog

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"