How can two boilers with the same number of sections be used for different amounts of steam?

DaveEvans

New boiler in an old cottage with way oversized old boiler.

The Burnham SteamMax 125 and 150 both have four sections. The latter has a larger output gas valve. But how can the latter make more sq ft of steam boiling the same amount of water?

Thx.

EdTheHeaterMan

What is the BTU input of the burners? If that is different, there is your answer. You can boil water on the small burner on your stove top with the flame on low, and it will take hours. When you put that same pot of water on the large burner set on high, it will boil much faster.

When you read these charts there are words built in to the charts that are not written on every specification line. Like BTU per hour. That per hour is the key. There are 4 dimensions on the amount of steam a boiler will develop. If you have a container, there are 3 dimensions, length, width, and hight. Those dimensions determine the volume. The 4th dimension is time. That is the one you forgot.

By the way, if you were to fire only 3 burners in the EG 40 boiler, it would have about the same Sq.Ft. as the 3 section boiler. But it would be a waste of cast iron, and would probably burn a little less efficiently.

And the Square foot you are reading on that chart is not a volume of steam in a measurement sense, like gallons or volume. Square feet is two dimension measurement, That Sq Ft number is to be used to match the surface area of the radiators connected to the boiler. The surface of the pipes and radiators can be measured in square feet.