Evaporative cooling

[napalisherpa]

Getting ready to put an order together for an automated gh and I was hoping to get opinions on evaporative cooling. Is it worth the cost? I'm in the foothills at about 2000 feet and get quite a lot of 100 degree days. Do you think I'm better off just using the roll up sides and opening the ridge vent instead?

Thanks

 

[EsterEssence]

Swamp coolers are only good for veg, they add to much moisture for buds...

 

[wolfhoundaddy]

swamp cooler

swamp cooler

They are pretty effective. We built 4 gh 30' ft wide ea. The back wall held a bank of cardcoard type pads, the other end had two large fans pulling the air through the gh. Also had vented roof and shade cloth on motor drive. We are a mile high in central az. and we will get towards 100 degrees. If you're handy with tools it would be cheap to build.

 

[furrywall11]

I'm setting up my greenhouse purchase right now too...bout 2200 feet in the foothills. I asked dude if evaporative cooling is worth it for my 1500 sq foot greenhouse and he said digging some 2 foot deep 10 foot long trenches and running ducting through it attached to some intake fans is going to cool the greenhouse enough without all the moisture.

 

[BAKED_BEANZ]

furywall can you elaborate on the cooling trench technique pls

 

[Rainmaker]

Swamp coolers are only good for veg, they add to much moisture for buds...

Bullshit...if you're growing in a place that's dry enough...the little amount of moisture..coming from the pad...running though the GH..ain't gonna make a bit of difference.

Now that we've laid that one to rest....Evaporative cooling can be highly beneficial in an environment where constant heat is an issue. The biggest factor to consider when running an evaporative cooling system is your access to available water. If that's not an issue...the cooling system can be very effective. You can get increased yields...quality..and bud density...by keeping a more consistent temperature in the structure. It's a fairly simple solution to high temps during the hot season...

 

[napalisherpa]

Bullshit...if you're growing in a place that's dry enough...the little amount of moisture..coming from the pad...running though the GH..ain't gonna make a bit of difference.

Now that we've laid that one to rest....Evaporative cooling can be highly beneficial in an environment where constant heat is an issue. The biggest factor to consider when running an evaporative cooling system is your access to available water. If that's not an issue...the cooling system can be very effective. You can get increased yields...quality..and bud density...by keeping a more consistent temperature in the structure. It's a fairly simple solution to high temps during the hot season...

Thank you very much for the reply. This is the line of thought I've been leaning toward!

 

[Crusader Rabbit]

Evaporative coolers work when their water can evaporate; dry air. If your location is hot and humid then they can't do their job.

 

[EsterEssence]

I live where it is dry as hell, in my case i would not use it in bud...

 

[Jhhnn]

Evaporative coolers work when their water can evaporate; dry air. If your location is hot and humid then they can't do their job.

Entirely true. We use one on the house here in Denver. There are a few days during the monsoon season where it has little effect because of high humidity.

They're also useful in avoiding VPD, helping to keep RH up. Plants are a lot more heat resistant at higher humidity-

https://www.icmag.com/ic/showthread.php?t=179909

Effectiveness falls off rapidly as scale builds up on the pads in hard water areas. Using a purge pump slows down that process.

 

[Grownomenal]

I've worked in several hog houses that were a couple thousand square feet and had evaporative coolers and even on a summer day they were still cool. Humid yes but cool. The farm used retention pond water so they didn't have to pay for city water or pump from a well.

 

[furrywall11]

The question is simple, what is the RH in a greenhouse with evaporative cooling? I have a feeling that it might not be a good idea to run evaporative cooling during in the summer during the closed up night period....but, I guess a lot of people do it so who knows..

anyways, the trench thing:

you dig a 2 foot deep 20 foot long trench and lay 12" metal ducting in it that comes up in an elbow in the greenhouse then some cubic foot appropriate fans to vent hot air from the greenhouse and the negative pressure draws air from the 12" ducting which is now very cool because it's been running through a chilled metal duct....you can also put fans on the metal ducting to force air through if you want.

I'm going with this technique because I can utilize smaller fans with filers on them to muffle sound....My neighbors are very sensitive so noise is one of the biggest factors for me.

 

[BAKED_BEANZ]

thanks for clearing the trench suggestion up. i had kind of figured out what you had meant. i have horizontal air fans. to circulate and help exchange air. but have no real effect on cooling .

 

[Jhhnn]

The question is simple, what is the RH in a greenhouse with evaporative cooling? I have a feeling that it might not be a good idea to run evaporative cooling during in the summer during the closed up night period....but, I guess a lot of people do it so who knows..

anyways, the trench thing:

you dig a 2 foot deep 20 foot long trench and lay 12" metal ducting in it that comes up in an elbow in the greenhouse then some cubic foot appropriate fans to vent hot air from the greenhouse and the negative pressure draws air from the 12" ducting which is now very cool because it's been running through a chilled metal duct....you can also put fans on the metal ducting to force air through if you want.

I'm going with this technique because I can utilize smaller fans with filers on them to muffle sound....My neighbors are very sensitive so noise is one of the biggest factors for me.

Evap coolers can be run on thermostats and/or RH controllers. They can run on vent or be switched off at night.

 

[Jhhnn]

The question is simple, what is the RH in a greenhouse with evaporative cooling? I have a feeling that it might not be a good idea to run evaporative cooling during in the summer during the closed up night period....but, I guess a lot of people do it so who knows..

anyways, the trench thing:

you dig a 2 foot deep 20 foot long trench and lay 12" metal ducting in it that comes up in an elbow in the greenhouse then some cubic foot appropriate fans to vent hot air from the greenhouse and the negative pressure draws air from the 12" ducting which is now very cool because it's been running through a chilled metal duct....you can also put fans on the metal ducting to force air through if you want.

I'm going with this technique because I can utilize smaller fans with filers on them to muffle sound....My neighbors are very sensitive so noise is one of the biggest factors for me.

Don't expect the same level of benefit available from evap cooling which exploits the heat of transformation.

There's no engineering obstacle to having very quiet evap coolers- it's just an issue of having very large pad area & large quiet fans driving the process.

 

[kmk420kali]

In our 6000 sq ft greenhouse, we use 5, 7000 CFM Master Cool coolers-- The deal with Swampers, is you have to have proper exhaust or they don't work...and yes, it needs to be in a dry environment-- We are in the desert, so they have been working perfectly--
We are building a new place right now, another 6000 sq ft, and we are using a water wall this time-- That is a wall of pads on one side, and on the opposite side big fans to pull air through the pads-- Just waiting for that to show up now-- I'll post pics when it is up and running--

Here is a vid of the same type system we are getting-- https://www.youtube.com/watch?v=CVPVJ6GXkN8

 

[mojave green]

How much for the one with wet wall?

 

[kmk420kali]

How much for the one with wet wall?

We are buying 2, since we have 2 buildings-- For a 48X56 ft building, we need 25 ft wet wall, 4 ft high, 6 inches thick....with 3 36 inch fans pulling from the opposite side-- About 5 grand, each--

But, we will save massively, as we only have to power 3 fans and a small pump...and you don't need fans inside on the plants, as the whole place will be exchanged every minute--