Choosing a boiler

AMservices

I recently condemned an old bryant steam boiler model# 244 - 7. The boiler has in input of 450000 BTUs and an output of 360000 BTUs.
There are 22 radiators, 18 column style radiators + 4 indirect floor radiators.
I measured the system EDR to be 1500 square feet of steam. Looking around the building the piping is still very well-insulated.
I've been looking at boilers for 3 days and getting pricing. Luckily nobody is living in the home at the moment because every boiler is 2-3 weeks out.
All the boilers I'm looking at that are capable of producing 1500 square feet of steam have a gas input around 650000 BTUs and a output of around 580000.
I converted the btu output off the old boiler to tell me how much Steam the Bryant boiler was making and I found it to be 1500 square feet.
So I have couple questions about picking the new boiler.
Do I want to install the boiler that is 200000 BTUs more than the old one? I know that 200000 BTUs is my hidden 33% pickup Factor. It just seems like a lot of added capacity considering how well insulated everything is.
And my second question is what boiler would you recommend? I was liking the weil McLain LGB - 6, I just don't like how it only has 1 Supply tapping off the side and it's a 6-inch tapping, so I would feel it necessary to make the entire header 6 inch.
Any recommendations would be greatly appreciated.
Thank you

ChrisJ

My opinion is the 33% pickup factor is ridiculous and unnecessary. At the same time, I've tried to recommend most go with something 15-25% or so, just for some wiggle room. I'm personally running 10% in my home but wish I could try lower just for fun.

But, you say the old boiler had 0 pickup factor but the system heated fine? If that's the case I'd try to get as close to that as I could. Go a little over if you have to, but don't go under. Certainly don't go 33% over if 0% was working.

Not sure on what boiler to recommend in that size, but I feel multiple risers perform better than a single even if they're the same amount of volume.

nicholas bonham-carter

This might be a use for a two 300,000 BTU boiler setup. Smaller boilers may be more easily obtainable, and when controlled by pressure, and a two-stage thermostat, would cover the pickup factor only for the initial warmup, and for polar vortex heating, after which the lag boiler would cut out.--NBC

AMservices

Not sure how well the system heated the building. It was dead when I got there.
I've never twins steam boilers together. The Boiler Room is small and as much as I like the idea, I don't think 2 boilers will fit.
Currently the boiler only has a gravity return.
If I twin steam boilers together, would I need a condensate receiver tank and to boiler feed pumps?

ChrisJ

Any boilers with a with a DOE output of 415,000 - 450,000?

New England SteamWorks

WM 80.

Where are you located? Shouldn't have to wait but a day or two.

Fred

Are there any mechanical or electric valves on any of the mains that might suggest they only heated half the building at a time? Is there anyone who can tell you how the building heated before the old boiler died?

AMservices

RI_SteamWorks said:

WM 80.

Where are you located? Shouldn't have to wait but a day or two.

North of Boston. Jobs in the city of sin, or Lynn mass for non-locals.
I'll track that down tomorrow.

There are no mechanical valves, only 2-4" gate valves. 1 valve shuts the large function room with the 4 indirect radiators. The other serves the rest of the house.
According to the guy hiring me It was working when he bought it, but he also said he was filling it every day. How he didn't notice the sauna in the basement, that wasn't in the sales description beats me.
The owner asked if I could separate the 1st and 2nd floors radiators because he wants to sell them off as condos.
I told him it would cost more to remove the Asbestos then it would to re-pipe the entire house after.
So I'll put a outdoor reset control, change all the radiator valves and TRV air vents throughout.
Maybe I'll put Dr. Izhadanovsky vacuum system in and try zoning that.
Going to be interesting that's for sure.