Cooling potential
Will the cooler work today?
An evaporative cooler can only cool air toward its wet-bulb temperature, which depends on heat and humidity. Enter today's temperature and humidity to see that floor and the gap below the outdoor air. A big gap means strong cooling weather; a small one means a humid day when any cooler struggles.
Check it
Temperature and humidity in, wet-bulb out
Wet-bulb temperature
The wet-bulb temperature is the floor evaporation works toward. A real cooler supplies air warmer than this; how much warmer depends on the pads, airflow and upkeep. The bands are this site's plain-language grouping (20 F or more strong, 12 to 20 F fair, under 12 F weak), not an industry standard.
Grand Junction months at their average high
Each month at its average high and its average humidity. This is conservative: the monthly humidity includes cool nights, and afternoon humidity on a hot day usually runs lower.
| Month | Avg high F | Avg humidity % | Wet-bulb F | Gap F | Band |
|---|---|---|---|---|---|
| April | 65.8 | 35.2 | 51.2 | 14.6 | Fair |
| May | 76.8 | 27.8 | 57.3 | 19.5 | Fair |
| June | 89.2 | 22.8 | 64.2 | 25 | Strong |
| July | 94.5 | 34 | 73.3 | 21.2 | Strong |
| August | 90.9 | 34.2 | 70.5 | 20.4 | Strong |
| September | 81.7 | 38.3 | 64.7 | 17 | Fair |
| October | 66.9 | 50.6 | 55.9 | 11 | Weak |
The formula. Stull (2011), a published fit for wet-bulb temperature from air temperature and relative humidity, valid for about 5 to 99 percent humidity. It assumes sea-level pressure; at Grand Valley elevations the true wet-bulb is a little lower, so the gap shown is slightly conservative.
What a cooler does with it. The Department of Energy says direct evaporative coolers can lower air temperature by 15 F to 40 F. They never reach the wet-bulb temperature itself; pads, airflow and upkeep decide how close they get.
Ready to send it in?
One form covers repair, startup, winterizing and replacement. Photos from the ground or from inside help.