Raised flue vs drop flue

[Buckfever]

What's the difference in performance between raised flue pans and drop flue pans? Is there an advantage to one over the other?

[Thompson's Tree Farm]

Ford, Chevy, Dodge

[MISugarDaddy]

Only difference that I know of is that with raised flue, you don't have the risk of hitting a flue when firing. I have had both and I don't deny hitting the drop flue a few times when I was in a hurry firing, but the evaporator was only a 2 x 4 unit so the flue section of the pan was closer to the front of the arch.
Gary

[BAP]

Raised flue has the advantage of the sap level sitting several inches higher than the syrup pan. Because it sits higher, it flows easily from the flue pan into the syrup pan float box. On a drop flue you don't have that height drop. Sap flows from one another pan to the other to keep the level set by the float, but doesn't have the height drop to make it flow faster.

[wnybassman]

With a raised flue you don't have to worry about freezing the flues as bad during a cold snap, plus they are easier to drain empty from what I hear.

[motowbrowne]

To me the advantage of the raised flue is that you have two float boxes. That allows you to run the syrup pan however deep you like while not running the flue pan unnecessarily deep. I typically run my flue pan 1/4"-1/2" deep and my syrup pan about 2" deep. Can't do that on a drop flue. Also, as others have mentioned, not worrying about your buddies hitting the flues with firewood is nice.

Beyond that, though, millions of gallons of syrup have been made on both types of rigs. They both do the job.