How Do You Size A Commercial Boiler?

Choosing the properly-sized boiler is absolutely essential to your commercial operations. When your boiler is sized too small, you won’t generate the heat you need to keep yourself, your team, and any other stakeholders happy. On the flip side, when your boiler is oversized, it will start to cycle on and off too often. That creates massive wear and tear, and stops your building from heating efficiently.


Now, if you go online and you look up how to size a boiler, you’ll see one of two things: someone telling you that it’s just a matter of how big your building is, or someone going into insanely technical jargon. We’re going to go a slightly different route (though the technical jargon is often accurate, it’s not useful for most consumers).


Realistically, there are two factors that determine how a boiler should be sized. The first, to the credit of those touting this route, is the size of your building. The logic is simple enough – the bigger a building is, the more energy it will take to heat it.


The other major factor is heat loss. Heat loss occurs through the building envelope – doors, windows, walls, the roof, and to a lesser degree, the foundation of your building. Consequently, the better insulated the building envelope is, the less heat loss you’ll experience. The less heat loss you have, the less powerful your boiler needs to be.


You can look to Passive House designs for an extreme view on how insulation and HVAC interact. The whole principle of Passive House is that if you have sufficient insulation, you’ll only need to run your heating system occasionally because heat won’t seep through the envelope. On the other hand, a building with almost no insulation would require a powerful boiler running all the time to keep it warm.


Now to tip our hat to the more technical articles out there, it is true that sizing a boiler can be more complicated than figuring out how many BTUs you need based on size and heat loss. Some steam boilers, for example, quite literally need to send steam pumping through pipes running throughout your business. For these boilers, it’s important to calculate boiler horsepower. 


That brings us to a non sizing-related consideration – exactly what kind of boiler is going to be the most efficient for your business. That requires a detailed look at existing infrastructure, and from there, doing a cost-benefit analysis of the installation/purchase cost of the boiler versus how much money you’ll save in energy efficiency. Sizing is important, but it’s not the only thing that matters!


Fortunately, you don’t need to worry about any of this stuff (though we’re glad you read all the way through – the best customers are well-informed customers). Whether you need Winnipeg commercial boiler repair or a brand new commercial unit, Howell Mechanical is here for you.