Cooling Systems

[Jimmi Jones]

Hi all,

I was wondering if anyone here has installed or have any experience with Evaporative cooling pads and or misting systems. I am considering installing one to address the heat that we deal with here in Belize.

I am trying to determine which one of the two systems would be better for my application as we have high temps, similar to Florida or Texas and high humidity and I grow mainly Lettuce, some tomatoes and peppers.

Thanks for any info you can give.

Jimmi 

[Chris Carr]

Sorry I do not have an answer to your question but I know it is a common one. I am curious if anyone has some testing results/numbers with these system in humid conditions where they are much less effective than in dry areas like in a desert region.

I wanted to add something to this question as well if you don't mind. In year-round hot and humid conditions like this, is there any cost effective alternatives to evaporation systems? Is storing water in an underground sump in a tropical area any more effective then just keeping it well shaded since the year round temp doesn't change much? The only fluctuations you get I suppose are night/day.

Thanks.

[Chris Carr]

Sorry I suppose I was only considering regulating water temp not air temp.

[Jimmi Jones]

The water temps are fine, my fish tanks are completely shaded and the rafts cover the water so the water temps remain pretty stable and the growth is pretty good, but during the hotter parts of the day (between 11:00am and 3:00 pm the plants are stressed, especially the lettuce. The thing is, if we get cloud cover during those periods the plants do fine but when the sky is clear and if it is above 85 degrees the plants are obviously stressed.

 

As a result I have to harvest the lettuce about a week earlier than I usually would to avoid them getting bitter and going to seed. 

 

Thanks for your response

Chris said:

Sorry I suppose I was only considering regulating water temp not air temp.

[Chris Carr]

Sorry I was more trying to piggyback on your topic. I decided to just go ahead and post my own thread instead of highjacking yours :) I was curious, what does your water temp normal sit at? 

Anyway though, back to your topic, I look forward to hearing what others say about evaporation systems in humid climates.

[john tramell]

Jimmi are you growing in a hoop house or greenhouse as far as the cooling pads go what are you having to pay for elec.power will the cost of running fans to pull cool moist air thru the pads offset the cost .

 

[Attie Esterhuyse]

Hi Jimmi,

Evaporative cooling systems only work well in arid regions where the ambient air has a low relative humidity. The amount of cooling that you can get from these systems has to do with the amount of water that can be evaporated. So if you have a high relative humidity than there is no chance for a lot of cooling to take place. The same goes for misters.

 

The best option for you would be to try and keep the heat out. This can be done by making use of shade cloths or even splashing lime on the outer plastic surface of your hoop house. Remember that plants cannot utilise 100% of the incoming PAR (photosynthetically active radiation) anyway. Make sure that you have enough ventilation. Open up the sides of the hoophouse and maybe install insect screens to reduce the danger of pest invasion. Only grow plants that can tolerate your growing conditions.

 

This will be my recommendation. Other ways of cooling will be way too expensive for an aquaponic system.

 

Attie

 

[Diablo]

I bought some 40% shade cloth and a misting system to test. I'm in central west Florida, so in the summer it's normal to have 90 degree highs and high humidity. I would think the misting would work regardless of the humidity. I don't have an AP system up yet, but I could still test and see what effect it has.

[Dan Ponton]

Did the cloth and mister help. I am in Gainesville and this summer almost nothing grew, not even Chard or Kele.

Diablo said:

I bought some 40% shade cloth and a misting system to test. I'm in central west Florida, so in the summer it's normal to have 90 degree highs and high humidity. I would think the misting would work regardless of the humidity. I don't have an AP system up yet, but I could still test and see what effect it has.

[Kevin R.]

Not sure what exactly you are using the cooloer for but dont let the water from the cooler mix with you water for your fish or plants. Evaporator cooler filter pads usually are cover with a anti algae/ bacteria chemical. Trust me I learned this one the hard way. used as a filter material and killed all my fish with 2 hours and plants the next day.

 

 

[Jim Troyer]

I'm in the Phoenix Arizona Desert area. 

Regarding bright sunny days:

We must must use shade cloth during the summer months to keep the plants from burning leaves during the intense solar radiation between 10:00 and 4:00.  I don't do anything about the 110+ temperature, just 60% shade cloth.  Some Growers  use burlap for shade cloth, works well too.  Shade cloth holds up much longer however.

We actually have 5 seasons here in the Sonoran desert.  May-June is just hot and dry; July-September is a monsoon season where the dew point is above 55f.  Evaporative coolers are largely ineffective during the monsoon season.  Mist systems create other problems such as fungal infections.

I hope this helps some of you who are in direct sun areas but do not experience the heat associated with the desert.

Kevin makes a good point, rinse your cooler pads well if you are planning to use them for solids filters. 

Since Chris asked about your water temps, ours here in Phoenix get into the 80s with shade cloth.  Most larger systems are burying their fish tanks several feet into the ground to regulate water temperatures.  Our biggest problem with water temperatures is the winter over night temps that dip well into the 40s every night and high 20s on occasion.  Most of us lost tilapia this winter when we had record cold temps for 2 weeks in December.  My in-ground fish pond went to 48 degrees, the waterfall had ice in the morning!  Nile tilapia are good for about 49/50f...  The only good thing about this is we now know the lower limit for our fish and they are easy to catch when it is that cold, had a dining room full of fish for quite a while.

[Jimmi Jones]

Thanks Jim,

I have not invested in a cooling system yet but I am using shade cloth, just completed the install yesterday. I have partially shaded the screenhouse, to shade the plants during the hottest times of the day. I will give an update in a week or so as I have some time to evaluate how the plants respond to the shade.

Grace and peace  

Jim Troyer said:

I'm in the Phoenix Arizona Desert area. 

Regarding bright sunny days:

We must must use shade cloth during the summer months to keep the plants from burning leaves during the intense solar radiation between 10:00 and 4:00.  I don't do anything about the 110+ temperature, just 60% shade cloth.  Some Growers  use burlap for shade cloth, works well too.  Shade cloth holds up much longer however.

We actually have 5 seasons here in the Sonoran desert.  May-June is just hot and dry; July-September is a monsoon season where the dew point is above 55f.  Evaporative coolers are largely ineffective during the monsoon season.  Mist systems create other problems such as fungal infections.

I hope this helps some of you who are in direct sun areas but do not experience the heat associated with the desert.

Kevin makes a good point, rinse your cooler pads well if you are planning to use them for solids filters. 

Since Chris asked about your water temps, ours here in Phoenix get into the 80s with shade cloth.  Most larger systems are burying their fish tanks several feet into the ground to regulate water temperatures.  Our biggest problem with water temperatures is the winter over night temps that dip well into the 40s every night and high 20s on occasion.  Most of us lost tilapia this winter when we had record cold temps for 2 weeks in December.  My in-ground fish pond went to 48 degrees, the waterfall had ice in the morning!  Nile tilapia are good for about 49/50f...  The only good thing about this is we now know the lower limit for our fish and they are easy to catch when it is that cold, had a dining room full of fish for quite a while.