Swamp Cooler Door

This is a modified double doors that were in place. the original solution sprayed water at the door, but the amount of overspray was a constant probable. This drawing shows the flow of air, I do not show the 4 very large fans drawing air, but they are there. Also, yes I know water and servers are bad, but the amount this actually increases the humidity is negligible and to be honest, We don't care. So enough said about that.

My main concerns so far with this project are:

-Running the pumps dry because they call for water when the main reservoir is empty

-Algae build up

-Drain holes at the top getting plugged up

-uncovered water top and bottom (plan in place to cover)

-Bottom pre filters do not have any filter medium in them.

-Water source is a garden hose that someone could detach

-Not sure that the person who told me this was on GFCI breaker is actually correct because of a shock I received from the water during testing.

-Deer may drink from this so chemical cleaning solutions are a no go until its covered.

-bugs love wet matting

-the blue shit sheds...

First pump test showing the water running. Later tests show that we need a lot more water volume.

Stood the tray up to clean it. (float valve at the bottom)

1/4" connection to the float valve

Float valve connection

float valve

float switch on the top reservoir with water. We figured out later that the switch is backwards for our needs. So we used a automotive relay to invert its logic.

Float switch dry

Load test on the top reservoir, needed to make sure if something happened it would not pull away from the wall. note how everything leans away from the building.

water pump mounted on the wall, with main water line (blue) attached.

bottom (main) reservoir filled with water and showing the two pre-filters made from some short PVC pipe.

Top reservoir shot just for reafference.

All images

This does NOT include the Galvanized structure ($1,250.00) made by Service Plus and does not include the Evaporative Matting (also from Service Plus)


Until I do a better drawing here is the circuit. This uses SSRs and 12vDC automotive relays (though the automotive relays are temporary) they are to invert the logic of the float switch because all I could find was a Normally Open switch for the "If there is water, turn on the pump" situation, not the "There is no water, turn on the pump" situation.

UPDATE - 06-05-2021

Well my concern about the holes in the top revivor have come true. Basically the little bits of matting from the filter medium were getting picked up by the pump and stuck in the drain holes. My solution was a couple changes. One, I widened the holes, two I double the number of holes. Then I added two layers of screen mesh. One covers the whole top revivor and the other dips down in to the top revivor so the water being pumped in to it is hitting screen material first. This means I am filtering out bugs and other crap from falling in to the top revivor and I am filtering the water being pumped up.

FOLLOWUP - 06-10-2021 -- No further issues with plugged holes on the top revivor though the amount of dirt and debris in the bottom revivor is going to be an issue.

UPDATE - 06-29-2021

Well I must admit, bugs know unique ways to die.

My water pickup in the bottom revivor that I had called a pre filter is really nothing more then a PVC pipe with holes in it. I did not actually use any filter medium in it and I still think that was the right decission. What was not the right decission was to rely on the 1/8" diameter holes to not get plugged. I had planned to cover the whole bottom resivour with a mesh net but, I think I have come up with something better now.

When I got a call from the guy who is monitoring this cooling system, he said that I had about 20 holes in the intake pipe and I had about 20 dead bugs, one per hole, plugging it up. Well a screen mesh still will not work in the tight space under the door so I made a quick solution:

I took a 1 1/4" black abs pipe.

Cut it just slightly longer then the white pickup pipe.

Put an end cap on it

Drill about 15 x 3/4" holes in it with a step bit

Rolled up screen material and slid it inside the pipe

I then simply slid that filter over the pickup and now the diameter of the holes are far grater then the diameter of the outlet so there is no real suction effect to speak up. Now any debris just float past the holes in the pipe.

i think if I was going to do this again, i would have joined the two intakes (left and right) as one long pre filter. I could make that adjustment now but the point of this project is to keep costs down. My thinking is, it would be even more holes and screen material to prevent crap from causing issues.

Another fun lesson to take away is that 45oC is hot enough to damage the impeller inside the pump when bugs make it so no water flows. I replaced the impeller and used Vaseline to lube the impeller and outer gasket of the pump, that was the wrong decision. It was good for the impeller but the gasket swelled up and kept slipping out of the housing when I tried to put the screws back in the pump. Only lube the impeller.

UPDATE - 07-20-2021

Well lesson learned. Turns out Princes Auto sells junk water pumps. I got one with a high flow rate and a high duty cycle, but it appears the 80% it advertises is not at all correct. I am currently trying to source another option. I tried the generic Princes Auto brand and this one (https://www.princessauto.com/en/115v-pony-pump/product/PA0005771233) but they are both garbage. I have contacted an irrigation company and will see what they have to suggest. I have killed 4 of these pumps at this point and its only been two months (two frigging hot months, but still 2 months)

UPDATE - 07-27-2022

Even with a great big sign on the wall, someone managed to shut off the water supply and cook $500 in water pumps, and so I have decided to make some upgrades. The float valve that we use needed to be a little beefier as the calcium buildup after a summer of running doesn't really close anymore. The float switch in the top reservoir (more princes auto garbage) has failed, but I learned a very important lesson about how they work. There is a plastic nub that makes the float switch hesitate, this is done so the waves created by filling the top does not cause it to turn on and off in rapid succession. So, what ever I put in there in the future will need to be "De bounced" to prevent that issue. I need a water pressure sensor on the supply side to prevent the pumps from running when there is no pressure. I put the sensor beside the tap and before the reducer down to 1/4" nylon line so that even when it is fully open, there is still back pressure in the line. For a pressure sensor I am going to use a oil pressure sensor from a 1985 Honda Civic, the sensor is about $12 from Loardco. It presents a resistive value to monitor.