exhaust fan

[backyardsugarer]

I am going to have a 10" vent pipe in my roof over the flue pan and a 6" pipe vent over the syrup pan. I will have a 2X6 raised flue evaporator. Should I intall an exhaust fan like they sell at home depot or will the steam flow well enough with out it?

Chris

[smitty76]

Chris, I use 6" pipe with e blower to draw the steam out with enclosed hoods on the sap pan and flue pan. are your hoods closed or open on the sides? I am not sure if open hoods will draft enough without the blower but my enclosed hoods will. I use the blower so that when the hood doors are open the steam gos up the pipe and not the hood doors which makes it nice to look into more so for guest. One thing to think about is a blower with an external motor so that the steam and condensate do not go through the motor.

[backyardsugarer]

I will not have a hood this year so it will be open boiling. I will add that next year so that is why venting steam is a concern.

[smitty76]

That being the case, I would hook up the blower.

[jrthe3]

if your get the fans from home depot the one for venting addicts make sure you get the one that is made for over a bathroom cause the other one WILL NOT take the steam it kill them in less then a day of boiling found that the hard way

[Haynes Forest Products]

Smitty what CFM blower do you use Because I have seen this NOT work on rig because a small in the duct fan cant keep up with the rate that steam is pushed out by the natueral flow. If the only reason you have the fan/blower is to suck the steam out for viewing Souns like if you opened 2 covers at the same time it would draw by its self. Before I opened up the end of my hood for the syrup pan cover I didnt get pressure blowback from the hood. I would think on a 2x6 evap your getting 1 CFM of steam per second would take a heck of a fan per min to help the cause.

[smitty76]

Haynes,
I am not sure what the cfm's are but the blower is a 16" dia squirrel cage with a 10" square discharge and is belt driven so the motor is not in the steam. I can open all of my hood doors at the same time and the blower takes all of the steam and draws air in the doors as well, which that draw of air in the doors creates a clear, steam free view of the boiling sap. It works well and i have been doing it like this for years and it is still the same blower and motor i started with. I also use the blower so that the steam dicharge is out the gable end of SH so that i did not have to put holes through the roof and i could use smaller pipe(6") to lower the cost of pipe.

[Haynes Forest Products]

Smitty I understand I just dont want someone thinking a air assist duct fan will keep up. If it works and improves the viewing. My small doors when open you can see the steam drawing up the stack and then you forget how hot it is and you stick your hand in YIKES:mad: :cry: :emb:

[sapman]

Haynes, my experience is the exact same as yours.

Chris, I've got a 6" jack through the roof, and while you can see steam escaping from outdoors, you'd never know it from inside. It just hangs upstairs. I've got to get a fan hooked up before next season. Been three seasons like this so far.

Tim

[backyardsugarer]

Good call on the steam resistant bathroom fan. They are only about $100 and should help me draw the steam out. Anyone ever used an exhaust fan out the side of their shack near the ceiling?

Chris

[vtsnowedin]

Another thing to think about is that for a fan to work properly there has to be a way for replacement air to enter the building freely so that the fan is not working against a vacuum. This is not a problem in most old style sugar houses made of barn boards but a lot of the houses shown in members picture albums are pretty tight (and very nice looking I might add) and turning on a big fan will try to suck the doors open. Where to put that inlet vent so that it doesn't put a constant draft on the back of your neck or around your ankles will take some thought. I let in one four inch air pipe , (three would have been better)through the floor under the flue pan to feed the blower and put 4'X4' doors in both gable ends. One thing that might work in some sugar houses is a fan blowing in about five feet high directed at the stack end of the rig. Your stack and the walls near it would be cooler and the incoming air would be warmed a bit before it gets to you. Just a thought. now back to the wood pile. :D

[Haynes Forest Products]

vtsnowedin Is right about make up air. I have not been in one sugar shack that was up and running that didnt have a window or door open because of the heat being generated buy the evap. and the benefit is the make up air. If your getting steam blowing down and out the hood then maybe you dont have the windows or door at the right setting. WHAT yes Im always tweaking the amount of make up air with my coupla doors or windows I would rethink the fans a good running rig that has its stacks sized right dont have or need fans. Now with that said Im not saying that people dont have and use them and thinking they are working for them BUT Once installed you have to run them because you created an obstruction. Its like a wood stove until the stove is up and hot including the flue pipe they will smoke.