Inline duct fan for steam hood

[Chris Zeger]

Running a 2x3 evaporator currently building a steam hood to keep steam out of my shop. My question is can I put a elbow on top of steam hood and use a fan to pull steam out of the shop my evaporator sits a 3 or 4 feet from the wall so it would save me a lot of money rather than going through the roof which would be about 30 feet. Trying to get away with as little as possible because this will probably be my last year running this evaporator.

[DrTimPerkins]

Running a 2x3 evaporator currently building a steam hood to keep steam out of my shop. My question is can I put a elbow on top of steam hood and use a fan to pull steam out of the shop my evaporator sits a 3 or 4 feet from the wall so it would save me a lot of money rather than going through the roof which would be about 30 feet. Trying to get away with as little as possible because this will probably be my last year running this evaporator.

We do something similar in our "Maple Processing Research Facility" (4 3' x 10 evaporators = 12 possible roof penetrations), but on a larger scale. It works, however two drawbacks:

1. Fans don't last real long if the motors are in the stream of the steam (they overheat and burn out). You can get a really expensive motor that will survive these conditions, but that defeats the purpose of saving $ on going through the roof.

2. If the fan does stop, there is no natural draft, so you end up with a lot of steam in the sugarhouse.

15295

[tcross]

I'd say yes you can. I have a temporary hood I made out of strapping and plastic. it does not go through the roof due to the same situation... gonna change my whole set up in a year or two. I have it go out side the top of an old horse door via a fan. the fan is set at a very low speed so it doesn't suck the steam out too quickly. I have my preheater sitting inside it and I can get the sap to 150 deg pretty consistently.

[treehugger]

You'll have to be careful though. If you plan on putting a preheater in there and use a fan you'll likely draw in cooler air from the outside causing your preheater to not be as effective.

[tcross]

I've done it for 3 years with a 2'x2' box fan on the lowest setting, this will be my 4th, and I'm on my 2nd fan. just take the fan out every time you are done boiling and put it next to the arch while it is cooling down so it'll dry out a little. the reason mine busted (I think) was I left it in the opening overnight and it froze. flipped the switch on the fan upon starting the arch and didn't realize the fan was frozen... burnt out the motor. my preheater still warms up the sap between 120 and 150 degrees.

[Polish Wizard]

We do something similar in our "Maple Processing Research Facility" (4 3' x 10 evaporators
15295

Hi Doc,
I'm curious ----- what happens to all the maple syrup you make at the "research facility"?
Perks of the job?
Someone has to be the guinea pig.

Also, depending on how cheap someone plans to go with a fan installation ---
I thought about a similar concept and looked into fans at a big box home improvement store that would fit inside normal ductwork.
If I remember reading correctly, these fans are designed for moving conditioned room air and not built to be in contact with ANY moisture as indicated by the exposed motor --- so be careful what you buy if you plan to go really cheap as I was considering.

[DrTimPerkins]

I'm curious ----- what happens to all the maple syrup you make at the "research facility"?

We produce about 2,000-2,700 gal annually. It has been increasing as we add more taps each year, but our average production for the past 12 yrs is 0.59 gal syrup per tap. When I first started as Director we had about 1,400 taps....this year we'll have over 5,000. Syrup made in the production sugaring operation at UVM PMRC is primarily used in 4 ways.

1. Sold to the food service at UVM for use in the dining halls around campus (all syrup served at UVM is pure maple syrup....if you want the "other stuff", you have to ask for it and they'll go out back and get some for you). This accounts for about half our crop right now.
2. Given as gifts to UVM spears, visiting dignitaries, and as part of fund-raising. Also provided to UVM groups as donations for various activities. Fairly small amount.
3. Used in various research projects. Varies, but never more than a few drums each year.
4. Remaining inventory each year is sold to a packer. Up to about half our crop.

The proceeds from sales comes back to UVM PMRC to assist in funding the sugaring operation.

[Nogden3929]

For two previous years used a 6" inline fan from big box store. Rated for 210 CFM. Used a stove hood until I melted the plastic off.

This year had a custom hood built and moved up to two 8" inline fans rated for 470 CFM each. Got those online with free shipping. The vent traps cost as much as the fans.

Moving up to the 8" made a huge difference. Just be sure to keep your fingers out, they spin fast and hurt like.......