At only 7-1/2" tall, these quiet yet efficient low-profile ducted furnaces feature multi-ported stainless steel burners, sealed forced-draft combustion, automatic direct spark ignition and low amp draws. With up to nine duct connection choices, these models offer almost unlimited design flexibility. The SF-FQ models do not require exterior access doors which make them the more economical installation choice. Suburban Q-Series furnaces have been redesigned to be significantly quieter. Increasing the efficiency of the furnace blower to deliver more CFM, allowed Suburban Design Engineers to lower the motor RPM to deliver the same amount of air but at a substantially lower sound level. Dimensions: 7-1/2" H x 17" W x 20" D