Sap Pre Heater Length

[CharlieR]

Hi,

I'm going to build a pre heater for my homebuilt 2x6 hood I built last year.

I have a raised flue 2x3 and a flat 2x3 on the front, I was planning on extending my hood down to the top of the raised flue pan and putting a 3' pre heater just in there, but I am wondering whether it would be worth having it go the entire 6'.

I was planning on leaving the current gap of 16" over the front pan just so I can keep an eye on things.

Do you think i'll get much more benefit from the extra 3' of pre heater even though its under an open hood. Photo of hood attached from last year, the raised flue back pan will be a Christmas present!!

Thanks,
Charlie
14755

[Daryl]

Only cover the flue pan with the preheater. Set in on the top of the flue pan to maintain the heat in the hood.
Keep the front pan covered with a hood but high enough to still work in the pan. It can be the same hood but needs to have a steam barrier between the flue section and the syrup section.

[whity]

I would only go over the flue pan. We have our 3' long with manifolds at both ends and 9 lengths of 1/2 pipe. Don't forget a breather tube..