0-9,999

Heats spaces up to 500 sq. in.

10,000-19,999

Heats spaces 500 to 1,000 sq. in.

20,000-29,999

Heats spaces 1,000 to 1,500 sq. in.

30,000-39,999

Heats spaces 1,500 to 2,000 sq. in.

40,000-49,999

Heats spaces 2,000 to 2,500 sq. in.

50,000+

Heats spaces 2,500+ sq. in.