20 TAS=(110-32)/1.8'spec outdoor temp (C)
30 RHS=10'spec outdoor RH (%)
40 DTS=32/1.8'spec temp diff (C)
50 PAO=RHS/100*EXP(18.761-5248/(273+TAS))'spec outdoor vapor pressure (kPa)
60 PWO=EXP(18.761-5248/(273+(TAS-DTS)))'spec cooler vapor pressure (kPa)
70 CS=2000/2119'spec airflow (m^3/s)
80 QS=1200*CS*DTS'spec cooling power (watts)
90 PS=QS/2450000!'spec water evaporation rate (kg/s)
100 WO=.62198/(101.325/PAO-1)'spec outdoor humidity ratio
110 TI=(80-32)/1.8'indoor temp setpoint (C)
120 PWI=EXP(18.761-5248/(273+TI))'indoor cooler vapor pressure (kPa)
130 WI=.012'indoor humidity ratio setpoint
140 PAI=101.325/(1+.62198/WI)'cooler air vapor pressure (kPa)
150 P=PS*(PWI-PAI)/(PWO-PAO)'indoor water evaporation rate (kg/s)
160 C=P/(1.2*(WI-WO))'outdoor airflow with remote exhaust (m^3/s)
170 TA=(90-32)/1.8'outdoor temp (C)
180 Q=2450000!*P-1200*(TA-TI)*C'sensible cooling with Ta (C) (watts)
190 PRINT C,P,Q

ext airflow water flow cooling
(m^3/s) (kg/s) (watts)

.6835968 5.391054E-03 8650.772

With an 8651/420 = 20.6 COP and a 70.3 EER. I'd skip the special box and
put the cooler near a window with a 1-way plastic film intake damper, with
the exhaust fan and its film damper on the other side of the room. The box
only adds capacity vs efficiency.

Then again, the MMB10 cooler (which Adobe says can evaporate 3.2 gpm into
105 F air with a 65 F wet bulb) costs $298, and we might raise the COP...

With an 80 F sat vapor pressure of 1.047 "Hg and an indoor vapor pressure
of 0.566 "Hg at wi = 0.012, we might evaporate 0.1(Pw-Pa) = 0.0481 lb/h
from a square foot of damp surface in slow-moving air, ie make 30 lb/h of
water vapor with 30/0.048 = 624 ft^2 of surface in a 1'x2'x4' vertical
shoebox water sculpture near a window with a 1-way plastic film damper,
with a 2 watt Honeywell 6161B1000 motorized damper in another window.

If the sculpture contains 40 2'x4' 4 mm Coroplast sheets with 4 mm spacers
(about $80), that's 640 ft^2. The bottom might be a folded Coroplast tank
with a float valve and a fountain pump. We might sandwich the sheets with
vertical corrugations and horizontal spacers together and pump water into
a plastic film manifold at the bottom and let it exude from corrugations
at the top and run down the sides. Initial film coverage might improve as
mineral films build. We could clean it by pumping vinegar...

We could turn on a 10 watt fountain pump that can move 1 gpm up 5' with
an 80 F thermostat and open the damper when the indoor RH rises to 56%,
making 8500 watts of cooling with 10 watts (the damper only draws power
when moving) with a COP of 850 and a 2900 EER :-)

Nick