Swamp Cooler

This is the first year I’ve used a swamp cooler.  I did a lot of research on the cost effectiveness, yet I was hesitant to invest in one.  I wasn’t sure it would pay itself back.  Then, my neighbors offered me one for free (and installed it!).  How could I refuse?!

I started using it in Evaporative CoolerMay and was excited to find my May bill was down $67 from 2013.  ($119 in 2013, $52 in 2014).

I fared even better on the June Bill.  $81 savings.  ($158 in 2013, $77 in 2014).

Less energy use and I was feeling more comfortable and less confined than when I run the AC.  With the AC I try to use it as little as possible, but the evaporative cooler was so efficient, I just ran it whenever I pleased – sometimes 24 hours a day.

We are approaching the humid time of the year and the ability for an evaporative cooler to work is decreasing.   Here is a chart I made in case you are interested.  This gives the typical humidity and temperature for Phoenix, Arizona and what to expect from your cooler.

chart showing cooling potential of swamp coolerThe May values checked out.  At the extreme, I found that when it hit 110 degrees outside, the inside of the house was 80-83.  As soon as the sun set it would cool down to the mid 70’s inside.  This is identical to the program I would run my AC at.  My weekday air conditioning program is 76 degrees most of the day and 85 degrees between noon and 7pm.  I’m on an APS time of use plan that gives me higher cost between noon and 7pm – so I try to tolerate a little more heat than I like during those times.

Just this week things have been heating up more than I like.  My afternoon highs indoors are ranging from 84 to 88 degrees.  This matches the predictions from the chart, so no surprise.  Typically evaporative coolers are not useful here in Phoenix in July and August.  I was sort of hoping I could keep it going longer.  A look at the weather predictions suggest that the batch of high humidity will give a way for a few days and then it will stay steady in the inefficient range.  My plan is to switch to AC on Sunday July 6th.