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Sizing Replacement Boiler
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Kraft570
Member Posts: 1
Hello
I am looking to replace a steam boiler in my grandfathers house.
The current boiler is a Peerless 6105 STDGSP
404 Square feet Steam
97,000 BTU/HR OF steam
Natural Gas
I went throughout the house and calculated all the radiators using Weil McLain radiation sizing chart and came up with 326 square feet of steam 78,000 btu/hr.
Should I go with a boiler that matches my calculations or one that is a closer match what is in there?
I have pictures and more information if any one can help with some knowledgeable guidance
Thanks
I am looking to replace a steam boiler in my grandfathers house.
The current boiler is a Peerless 6105 STDGSP
404 Square feet Steam
97,000 BTU/HR OF steam
Natural Gas
I went throughout the house and calculated all the radiators using Weil McLain radiation sizing chart and came up with 326 square feet of steam 78,000 btu/hr.
Should I go with a boiler that matches my calculations or one that is a closer match what is in there?
I have pictures and more information if any one can help with some knowledgeable guidance
Thanks
0
Comments

If the steam pipes are properly insulated, there is nothing unusual about the system and you are sure of your numbers, select the new boiler to carry 326 ft.² of steam.
Oversizing of boilers and furnaces is an unfortunate but very common practice. It’s unusual to find a steam boiler that is not too large for the load.—
Bburd0 
I assume that since you are using a Weil McLain radiation sizing chart, you intend to install a Weil McLain steam boiler. If this is the case, you have a few questions to ask.
1. Is this the original boiler to the system? Could someone else have calculated wrong.
2. Are your calculations correct? I only calculate a difference of 78 Sq. ft.
3. Do you plan to install a Weil McLain?
Weil McLain would be an easier decision as the EG40 is 325 Sq. ft. of steam with a 6 inch flue.
While the EG45 is 392 Sq. ft. of steam with a 6 inch flue. You would not want to lower from your calculations. However, 392 is now only a difference of 12 Sq. ft. from your current setup.
Let's see what others suggest.0 
I would use the EG40. Don't forget the boiler has a 33% pick up factor built in0

Agreed, with a calculation of 326 get the EG40, no way would I go to the 45 for 1 sq ft of radiation.
From everything I’ve heard, read, and seen, I’d assume the previous boiler is always oversized.1
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