Williamson Plant at Ridge and Madison Rd in Cincinnati, OH
Manufactured the Williamson Five in One.
Model 953-13-6161
Serial 6545016
A.G.A. Input Rating 135,000 BTU/HR
Bonnet Capacity 101,250 BTU/HR
Type of Gas NAT
note: this furnace was approximately 75% efficient
(output/input) 101250/135000 = 0.75
0.75 x 100% = 75%