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Cheap Evaporative Cooler

  • #21
Thanks Butch! :)

My sundew setup with light can heat up to about 80-85 with lights very close with the sides open. The lights will be enclosed in the HL setup, but farther from the plants. I may have to rig a weaker computer fan to suck out hot air during the day to keep it around 75, and then use the cooler to drop it 15 degrees overnight. But this is all estimation, I'll only know when I have the setup built, which isn't for another month.
  • #22
This is sort of like the "Aprilaire" humidifiers they sell for home humidification.
In fact when using a pump to spread the water, one of Aprilaire's filters may work even better,
as they have a coating that will help spread out the water without the calcium build-up preventing the water from moving all over the "filter".
Although likely more expensive, they may work better. (But then, maybe not!)

The normal "absorbant" type "filters" draw up water from a water reservoir, and indeed can get blocked up with calcium to the point where they don't work well. Using one with water pouring over the top is a "different than designed" operation for this type of "filter", so it will be interesting to see how this works & how well it holds up in time. (The Aprilaire type is NOT absorbant & is simply a place for the water to form thin films whereby it can be more easily evaporated. Possibly not as well as an absorbant type, however they did think thru about having mineral build-up & it seems most will flake off the filter & end up in the bottom of the reservoir. What does remain on the filter can be rinsed off a bit & the filter re-used for a time.) In my experience, these filters last longer than the paper/absorbant type, however are indeed more costly. (I have had both types of humidifiers & had filter fouling with the paper type quite rapidly. But then our water is high in minerals.)

Glad to see people are trying to improve things for growing, as there is always room for improvement! :bigthumpup:
So my congrats on the experimenting.
  • #23
Thank you for the comments! :)
I wasn't aware there were other filters, but I guess we will just see with time how this one holds up. One that is not absorbant may in fact do better, I had never considered that.
  • #24
Wow great idea drew thanks for info.
  • #25
Thanks! You are absolutely welcome, let me know if you get to make one.
  • #26
Looks very good for here - all our hot days have low humidity. Will make something similar when i get a greenhouse. :)
  • #27
Awesome! Thanks for the compliment :)
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  • #28
I'm definitely going to try this.
  • #29
Please do! I'm finally going to set up the HL shelf this week and put it to use.
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  • #31
im going to make one soon but was wondering do the fans push the air out or in?
also if i put this on a rack in my growroom would it work just as well as if i vent the humidity in from outside?
  • #32
Just remember, this will only cool the air when the outdoor humidity is low (17%), or better yet (5%) :awesome:
  • #35
I would pull the air through the fans. It's easier to duct as well as being more efficient. Basically, the dry air can hold more water vapor than already humid air. This will allow it to absorb the pads water more, which further cools the pad, and cools the air.
  • #36
how high can the outside humidity beb before it stops working my basement is 54% would that work then its 65% in the summer
  • #37
if this does not work what humidifiers should i use
  • #38
I provided a link in the original post that will calculate the cooling effect based on your conditions.
  • #39
the link says the higher the humidity the cooler it gets or am i mis reading it
  • #40
The higher the humidity, the higher the dew point (the lowest temperature you could achieve). If the dew point is higher, the cooling effect is diminished; it is now cooling to a higher temperature.