Two-stage evaporative cooling

[Scott]

Anyone have any experience with two-stage swamp cooling? I've read about it
some, but I can't seem to find any information on a system that's suitably
sized for residential use. I've even considered home brewing one of my own,
but then I can't seem to locate any information about designing a suitable
heat exchanger.

Funny how I never think about this until the muggy summer rains arrive.

-Scott

 

[Ulysses]

Anyone have any experience with two-stage swamp cooling? I've read about it
some, but I can't seem to find any information on a system that's suitably
sized for residential use. I've even considered home brewing one of my own,
but then I can't seem to locate any information about designing a suitable
heat exchanger.

Funny how I never think about this until the muggy summer rains arrive.

-Scott

No responses yet eh? Hmmm....

Well, for what it's worth, I've made a couple of EV coolers and thought
about making it two-stage but I don't think it would really be worth the
trouble. Since evaporative coolers work better the dryer the air is trying
to cool damp air would probably only gain an additional cooling of a couple
of degrees and the whole thing would be more complicated and the maintenance
would probably be more difficult. Mine don't work all that great during the
"muggy summer rains" but work quite well the rest of the summer.

 

[Scott]

Well, for what it's worth, I've made a couple of EV coolers and thought
about making it two-stage but I don't think it would really be worth the
trouble. Since evaporative coolers work better the dryer the air is trying
to cool damp air would probably only gain an additional cooling of a couple
of degrees and the whole thing would be more complicated and the maintenance
would probably be more difficult.

Ah, you're thinking of having two sets of wet pads in the same air stream.
I also doubt that would be of much benefit. There are coolers with much
thicker pads (8-12") which are slightly more effective than the thin aspen
pads we get in the base models.

The two-stage cooler I've read about is built around an air-air heat
exchanger. Basically there's one evap cooler that makes cool wet air for
the exchanger, when then makes cool dry air for the 2nd evap cooler. The
2nd stage is somewhat less efficient, but it's still supposed to rival the
performance of a conventional AC under dry conditions, and at a lower energy
cost.