To size a boiler for a house, write down the dimension of each room that requires heating, labeling each room specifically. If the rooms are taller than 8 feet, measure the ceiling height and write it down. Check the type of insulation the house contains. Modern insulation and double glazed windows allow for a smaller heater, while older insulation types and windows require a larger heater. If the home contains fireplaces with chimneys, it requires a larger boiler.Continue Reading
Discover the area of each room by multiplying the dimensions from the notes taken. For example, for a room that is 25-by-25 feet, multiply 25 by 25 to get an area of 625 square feet. Add up the area of each room you need to heat to find the total area. Calculate the square root of that number and round up or down to the closest whole number to get the average area.
Using a BTU calculator, enter the average area and press the calculate button. The calculator provides a minimum and a maximum number, which you can use to determine the boiler size you need. The range provided typically allows for the variance caused by insulation, windows and chimneys. If in doubt, ask a professional to check your calculations before purchasing a boiler.Learn more about Heating & Cooling