Turbine Vents

[newman_maple]

I have put up an enclosed carport and plan to put a 2 x 4 or 2 x 6 evaporator in it. I planned to place four 12" turbine vents about the pan. The roof peak is about 11 feet from ground level. Does this sound reasonable? A cupola is not really going to work so I need a suitable venting solution. I cannot really afford (or want) a steam hood.

Any thoughts/ideas will be appreciated.

Eric

[Haynes Forest Products]

I dont think you will get any benefit using the turbine type vent. With a open type bldg. you dont built pressure to spin the vents. They look cool but steam laden air moves alot slower than heat from a attic on a 95 degree day when the inside the attic is 120

[newman_maple]

Thank you for your reply. I have been wondering about this issue. There are other types of passive vents to use in lieu of turbines, but I just do not know if steam can escape well enough. I am hoping a will get some ideas on this site before I make a mistake.

[Grade "A"]

Could you use a fan to force the steam out?

[Valley View Sugarhouse]

I have a friend with 2 oil fired barrell arches, he has a 2x2 hole and a 2 foot round vapor tight fan, this works very well.. a little noisy but steam free..

[WESTVIRGINIAMAPLER]

Why not install and attice vent fan on one end of the building at the highest possible peak and control it with a switch and not a thermostat. They are around $ 70 @ Lowes.

[newman_maple]

The building is set with one end 8" higher than the other end (8" over 31"). I will place the evaporator at the higher end as close as I can safely run the stack up. I was planning on 36" from the wall. The steam will want to stay at the evaporator end and will be only a few feet from the wall.

I had planned to put a regular gable vent in that end, but a fan might be better. This year, I do not have permanent electricity in the building, but do have it corded to the house for lighting. A large fan might be too much with my current elec. setup. Also, the steam would run along the roof across the stove pipe. I guess this would not be a problem.

I have looked at some gable mounted exhaust fans that are not too expensive. Would it seem reasonable to use a 12" or 16 " fan and go ahead and place the 12" vent mounts (I already have) and place a rain cap on them. I think the four 12" holes with a cap, either a standard cap or a vacuum cap might be sufficient.

[Haynes Forest Products]

Air is like water it takes the path of least resistance. I had a squirl cage blower to suck the steam out of the end of the sap shack and it didnt work well at all. With that said If you have alot of roof vents and a fan in the peak you could end up pulling in the cold air from the vents. Remember steam that you can see is the heavy air and it doesnt like to move like the steam that you cant see. Thats right you know the steam that goes up your nose and curls your hair when you look into the flue pan when you think its not boiling heavy.

[newman_maple]

I understand that it is possible that a fan could be counter productive if it can pull air in through the vents.

Does anyone think four or even six 12" holes (with rain caps) would be enough to let the steam out? I would prefer to simply let it move straight up and out. I considered placing some sheet metal up to catch the steam as it works it way out.

Any thoughts?? Any ideas are appreciated.

[Pete33Vt]

Around here alot of people use plastic to build a hood over the whole rig to make like a tunnel to divert all the steam to there vent or cuoplua, you get some condensation off from it but it gives the steam and area to follow to get to the vents. four -six 12" holes should work. Granted you may still have some steam in the sugarhouse but thats part of the whole experiance. If they do not work as planned you can redesign next year.Just my 2cents

[AGR1093]

I have a similar problem, I have a large building with a nearly flat roof, not peaked, and it has a real low pitch. I am not sure of the best way to vent the steam, any ideas?

[Haynes Forest Products]

(((((((((((((((((((((((((((((((((((((((((((((((((( (cupola))))))))))))))))))))))))))))))))))))))))))) ))))))))))))))

[newman_maple]

Pete, you mentioned using plastic to funnel the steam to the vents. Are you referring to regular clear plastic? I know 4-6 mil plastic is not that expensive in large sheets. That would not be too difficult to put up. How far above the pan should the plastic be?

Haynes is correct about a cupola, but that would be a major undertaking in this building.

[maple flats]

I went on a maple tour about 4 yrs ago and one producer on the tour, with a 4x14 evap had a wooden frame over sized slightly compared to the evap and he had clear plastic stapled to the firring strip frame to form a hood of sorts. He said it was very effective, but the tour was not during maple season so I never saw it in action. He had it go up to a cupola but I would think you could have it go up to a couple of vents. I have a homemade aluminum hood on my 3x8 which covers the 3x6 flue pan and extends elevated about 16" above the 2x3 syrup pan for about 18-20 inches. All of this hood has 2 steam stacks each 10" at the hood increased to 12" for 6' high and then 10" hung from above dropping into the 12". These go up to the cupola but end a the cupola door bottoms height. The steam all or at least 95%+ goes out the cupola thru these stacks. You should be able to build something simple to do the same thing. The reason I have both 10" and 12" stack on mine is because I made it so I can raise the hood by means of a winch at any time by just cranking the winch. To lower it i just lower the winch and everything goes right back into place. The hood is supported by a cable at each corner and the cables go up plumb to a pulley and then to the winch which pulls all 4 corners equally.