Flue or flat? That is the question.

[snowman]

Well i'm making the jump from hotel pans on a cement block oven, to an actual arch that measures a pan area of 24x47.I have 2 flat pans one with dividers one without not sure if I want to use them. If I were to get new pans is it worth drop fluing one pan and flat panning the other and if so what sizes? or should I just flat pan the whole thing? I have 30 or so taps and plan to grow little by little.

Thank you for your input, spring can't come quick enough.

[psparr]

Just my 2 cents, but it will be hard to gather enough sap to keep a flue pan happy with 30 taps.

[mellondome]

On a 2x4 with 30 taps.. why not a flue pan? You an get a combination flue/flat pan for not much more than flat pans. And it will allow you to expand more if you like. I used to run 45 taps on a 2x6 raised flue.
It comes down to time and money. You want to spend 3 or 6 hours a day boiling? You want to max out your tap count where you are or expand to 100 taps over time. You into making syrup or just an excuse to hide in the garage every night with the guys and drink sodas.
I enjoy boiling, but I also need sleep and time with family away from the evaporator. So I would say flue all the way... you won't regret it.

[BreezyHill]

I am with MD. I have a 2x6 air tight arch with a dual fan for AUF with raised flue. 2013 boiled for nearly 18 hrs a day all season on 250 taps and high vac. Last season got 650 retubed and the RO back on line and would boil for 2-3 hours; but our weather was poor.

last season we were hitting around 40-45 gallons per hour. Never really had enough concentrate to get the unit dialed in for a good days boiling.

18-20 hrs of boiling gets old after a week and for 5-6 weeks it is a down right drag.

Buy the flue and never look back.

We plan to have over 1000 back on line for this season, and around 1500 for 2016. Not enough hors in the day to get all things done.

Ben

[Big_Eddy]

Well i'm making the jump from hotel pans on a cement block oven, to an actual arch that measures a pan area of 24x47.I have 2 flat pans one with dividers one without not sure if I want to use them. If I were to get new pans is it worth drop fluing one pan and flat panning the other and if so what sizes? or should I just flat pan the whole thing? I have 30 or so taps and plan to grow little by little.

Thank you for your input, spring can't come quick enough.

You don't tell us how you like / intend to boil. Batch process or continuous flow? Do you want to boil every day, or do you want to collect sap for the week and boil everything on the weekends? A 2x4 with flue pan will work for you if you sweeten it at the beginning of the season, then boil it regularly. It won't work with only 30 trees if you don't want to leave sweet in the pan. It will take a week or so to gather enough sap and a day of boiling to initially sweeten a flue pan, after which each day's sap will take a couple of hours to boil down. Flat pans only, the boiling time would be about double that.

Flue or flat, I would definitely build 2 pans and connect them (valved), instead of just 1 large pan. Having 2 pans gives you flexibility you don't get with a single pan. Coming from hotel pans, you are used to being able to collect concentrated syrup in one pan while boiling sap in another.

A typical ratio of front (syrup) pan to back (sap) pan is between 1:2 and 1:3. On a 2x4, I would go with an 18" front pan and a 30" back pan. It isn't overly critical, but the smaller the syrup pan, the more frequent (but smaller) your draws can be. For a small number of taps, that is an advantage to you. You will be producing ~1 gal of syrup for each good flow day so you want a draw size smaller than that.

Whichever way you go, I would recommend a divider in the syrup pan. The divider will help with developing a gradient and help with the draws. Not as necessary in the sap pan, but an advantage there too.

Ultimately, flat or flue will depend on your preferred boiling method and frequency, your future expansion plans, and whether you are comfortable leaving sweet in the pans over the season. With 30 trees, I'd probably stay with flat pans and replace the back pan with a flue pan when I hit 60+ trees. But then again, I always lean towards too much sap for the pan, as opposed to too much pan for the sap. You can always dump sap you can't boil, but you can't boil if you don't have (enough) sap for your pan.