What is the boiler rating for a single-family dwelling?

What is the boiler rating for a single-family dwelling?

• A. 100 MBtu/h
• B. 75 MBtu/h
• C. 7 inches
• D. 120 MBtu/h

Answer: (A)

Boiler rating is the maximum heat input the boiler is designed to deliver per hour, expressed in MBtu/h (thousand BTU per hour). For a typical single-family dwelling, about 100 MBtu/h (100,000 Btu/h) is a common sizing target, providing enough heat for coldest days without wasting energy from being oversized. The other options don’t fit because one is a length (7 inches), and the remaining ratings can be either undersized for many homes or oversized, which leads to inefficiency and short-cycling.

Boiler rating is the maximum heat input the boiler is designed to deliver per hour, expressed in MBtu/h (thousand BTU per hour). For a typical single-family dwelling, about 100 MBtu/h (100,000 Btu/h) is a common sizing target, providing enough heat for coldest days without wasting energy from being oversized. The other options don’t fit because one is a length (7 inches), and the remaining ratings can be either undersized for many homes or oversized, which leads to inefficiency and short-cycling.