I have a similar heat exchanger in my air handler along with the a/c coil. Air flow is fine, but the coil I have is fairly small (32K BTU). The key is to have a large enough exchanger and duct so that the back pressure stays within specs. Not sure if this is a spec that is measured for them. What you'd want to look for is the amount of backpressure at a certain airflow, then see if it would be within the furnace's specs.