HRS's scraped surface heat exchangers provide heat transfer solutions for viscous fluids & fouling. HRS Heat Exchangers designs and manufactures scraped surface heat exchangers for applications where either one or both of the following problems require special solutions: fouling causes heat...The heat exchanger is the metal component (inside the furnace and can't be easily seen) that heats up while the burners are running. Often, flame-rollout is caused by the furnace's blower-fan forcing air into the combustion-chamber through a crack in the heat-exchanger.Air cooled heat exchanger are used in petrochemical and refineries to utilize the atmospheric air to cool the hydrocarbon, process and utility fluids. In order to increase the heat transfer area, fins are also attached to the periphery of tubes. These heat exchangers are generally designed, inspected...Supported by the Performance Edge® thermostat and a variable-speed blower motor, this furnace will run in low stage up to 90% of the time. Longer, low-stage run times give you better energy efficiency, better temperature control and increased comfort. Gospel of matthew commentary pdf.