What brand of ventilation fan do you have?

MoonShadows

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#1
I would be interested in hearing about your ventilation fan. My greenhouse has passive roof vents, but I really need a wall ventilation fan for when the weather warms up. I have been reading about them, but my head is spinning. Can anyone recommend a good brand? My greenhouse is a bit over 1000 cubic feet.
 

waretrop

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#2
I have an automatic fan in the peak of the greenhouse. It automatic turns on if the temp goes above a certain temp. Then I have a very large fan that sits about 8 feet into the air. When the heaters are turned on it forces the heat downward out of the peak. I do have roof vent for summer but I don't use them anymore...
 

MoonShadows

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#3
I have an automatic fan in the peak of the greenhouse. It automatic turns on if the temp goes above a certain temp. Then I have a very large fan that sits about 8 feet into the air. When the heaters are turned on it forces the heat downward out of the peak. I do have roof vent for summer but I don't use them anymore...
I'm beginning to think roof vents are a nice "selling point" for greenhouse manufacturers but they are too passive and insufficient in venting the heat buildup when the temps really start to rise. For this, IMO, you have to have mechanical ventilation.
 
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#7
I found that the roof vent exhausts a lot more air since I installed louvres. You can actually feel the air whistling in. Stirring the air is also good for both cooling and then keeping the hot air mixed in instead of held in the peak during the winter.

DC fans run from solar panels work beautifully.

2014-09-07 13.51.57.jpg
 

MoonShadows

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#8
@Lori I like those small DC ceiling fans. Do you remember where you bought them? Are they reversible...pull air up in summer/push it down in winter?
 

MoonShadows

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#10
That's dirt cheap. Thanks for the link. I'm going to think about getting them. With the solar collector I am building, I will need more height in the greenhouse and won't be able to block off the upper part in the winter. This will push the heat back down and keep it from hiding up near the roof.
 

waretrop

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#11
When we first started out greenhouse probably 32 years ago we quickly realized that winter was the most important times to have fans. That condensation can be problematic. Everyone should know that going into building a greenhouse.
 

MoonShadows

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#12
https://www.ebay.ca/itm/DC12V-5W-Pl...805213?hash=item3621d4731d:g:5BoAAOSwXedZwzK3

They are not reversible however they move so much air that it doesn't matter. Looks like a mini hurricane when they run!
How many do you have in your greenhouse and how long is that greenhouse?

When we first started out greenhouse probably 32 years ago we quickly realized that winter was the most important times to have fans. That condensation can be problematic. Everyone should know that going into building a greenhouse.
And, I think most beginners probably think the opposite is true, and that makes sense because in our regular houses we only use fans in warm weather, but in a moist greenhouse, condensation is a real problem when it's cold outside.
 

waretrop

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#13
Yes, You can really develop a bug problem and molds.... with so much moisture stays for too long. That's why you really should only water early in the day. That way the plant leaves have time to dry out before the night, especially plantlets (babylets). LOL
 

waretrop

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#14
fan.jpg
Outside the greenhouse gable fan

fan1.jpg
Inside the greenhouse gable fan only used in summer

fan2.jpg
My VERY VERY large fan to hit the whole middle of the greenhouse in summer

fan3.jpg
Winter fan to move air away from furnace. This furnace elow is not used regularly. It only comes on automatically if the pellet stove fails.

fan4.jpg
This fan is aimed toward the greenhouse sliding door to stop condensation in winter so the water does not drip down into the door runner and freeze the door shut. This is only used in freeing cold weather like 0 degrees..... When it is 20 freezing does not happen and we really don't need the fan on.
 
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#16
That's dirt cheap. Thanks for the link. I'm going to think about getting them. With the solar collector I am building, I will need more height in the greenhouse and won't be able to block off the upper part in the winter. This will push the heat back down and keep it from hiding up near the roof.
The blades on these are very very breakable. And of course the sun makes them even more brittle. You have to make sure they are secure and don't get out of level. I wish they would sell the blades separately at a decent price but no, they want $5 each! Had some break so will be working on making some of my own... :)
 

waretrop

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#19
Yes, It was used and disassembled and the fella thought he remembered it being 5x7 ish.....LOL When we put it together we very quickly realized he was a little wrong. It's a good thing that we could handle his error financially.... LOL