Will a dehumidifier work well in conjunction with an evaporative (swamp) cooler?

Question

I live in the desert and use a swamp cooler, but lately the house is just getting too humid to be comfortable. Would it help to run a dehumidifier to eliminate some of the extra humidity being created by the cooler? Right now the inside temp is 80 degrees and the humidity is 48%.

Answer 1

That's like eating hamburgers while on a treadmill. The swamp cooler works by adding moisture to the air, just the opposite of the dehumidifier. You would need a large dehumidifier and this would cancel out any good the swamp cooler was doing. How about a whole house fan mounted in the ceiling with louvres that open when the fan is running. They are quite effective.

Answer 2

A 48 % relative humidity at 80 degrees F is not unreasonable. A dehumidifier will not likely remove much water under that set of conditions so it would be helpful.

If the exterior relative humidity is high, the swamp cooler's effectiveness is greatly reduced. What are the exterior relative humidity conditions like? Perhaps it is taxing the swamp cooler too much due to exterior conditions.

I assume the swam cooler's evaporative effluent is vented outside. If not, change this.

The dehumidifier would raise the inside temperature, reduce humidity only slightly and raise your energy costs. Net result is higher cost and little noticible difference.

Answer 3

A swampie is designed to flow high humidity laden air into your home which gives the evaporative cooling affect on your body. So if the ambient humidity is high enough the cooling effect is reduced, this is why swampies do not work in areas where the average humidity is usually high, the drier the air the more effective swampies cool. At 48%RH your swampie should be working satisfactorily. Check the pads in your swampie, make sure there aren't any gaps and see that the entire surfaces of the pads are damp with no dry areas.
Putting a humidifier in your home to reduce humidity is like trying to blow into a high wind, you will be just consuming extra power.
If you really want to be cool when the humidity rises you need refrigerated cooling.