Evaporative Cooler ("Swamp" Cooler) Question?

Question

I understand that evaporative coolers or "swamp" coolers tend to work better in dry environments and that they can result in increasing the humidity to an uncomfortable level and, ultimately, defeating their purpose.

What would happen if I used it in conjunction with a dehumidifier to counteract the additional humidity? Would it be more effective? Less effective?

I'm not absolutely certain of the physics behind the cooling process but I think it would work. The cooling effect would still occur and the additional humidity would disappear with the use of the dehumidifier.

Or would this concept of mine be nothing more than putting a humidifier and a dehumidifier in a room and letting them duke it out to no real effect?

Thanks for your help!

Answer 1

I lived a year in Fresno, CA, 1950, with a swamp cooler, and it was h**l. Your other responses don't seem to consider the 'comfort curve' of temp vs. humidity for equal comfort.

Dehumidifying the cooled air  would help. Such units have a plastic tank for the condensate, with a hose bib built in, but it's sealed. Cut out or puncture that seal, attach a length of small diameter garden hose, and lead it outside. Now you don't have to empty the tank or find a bucket.

A small opening for air to exit the room is probably a good idea, but not a large one, as hot air from outside will get in.

As a practical matter, a portable AC unit to fit in a window costs about the same as the dehumidifier. I found that a room size unit could cool the entire downstairs of a house in Portland OR, 2BR, kitchen, john, and LR.

Answer 2

you would be making an inefficient air conditioner. Which wouldn't work.

The dehumidifier works similar to an AC with a cooling coil to cool the air and condense out the water. But unlike an AC, the heat that is necessary to produce the cooling is just used to heat up the air. In an AC that heat is dumped outside the room.

So your dehumidifier removes the water and puts it in a bucket. You take that and put it in the evaporative cooler. A vicious circle that only results in heated air.

Another way to look at it is as a closed system. You have lots of energy going into the cooler and into the dehumidifier.  This comes out as heat. There is no way for the heat to escape, so you are heating the room, not cooling it.

.

Answer 3

And look at the heat balance

You reduce the temperature of air by evaporating water in the swamp cooler

(the latent heat of evaporation) x (mass of water evaporated)

You condense this same mass of water in a de-humidifier by removing the latent heat of evaporation

Work Done is doubled unnecessarily

Best solution:

1. Ensure the intake air of the cooler is only fresh outside air (install it in a window or via the terrace door)

2. Open all the other windows ofthe room to continuously expel the humidised air from the cooler

3. If you can afford the extra costs - install an exhaust fan at the opposite end of the room to continuously expel the humidised air to a better effect