Electric Baseboard- Square D Company Used Condition - Good The 7 units measure a total length of 37 feet, which is enough to heat a 24’ x 36’ area. May be willing to sell individual units for $3 per foot, for example, 6’ unit for $18. The size of the units are as follows: 1 @ 10’ 1 @ 6’ 2 @ 5’ 2 @ 4’ 1 @ 3’