My sump is in my garage. the door faces east and gets full on SUN year round. The Garage door is insulated as is the rest of the garage. it does get downright hot in the summer in there. I have a 1/4 HP chiller that keeps my system at 78.5 all year long. works well. now with the LED's it did run less. and when it did run, it cooled it much more quickly. at night I have a 800 CFM blower that blows air out of one window bringing in fresh air from the other. this helps alot to cool the garage in the summer evenings. I never let the tank get warm so I dont know how much trouble it really is without the chiller. IN the winter, the garage stays warm because of the humidity from the sump. I get a higher evap rate it seems in the winter time. the garage stays in the mid 40's even in teh 20's outside unless the door is opened. that said, to reduce evap and humidity in the garage, I have three cutouts of 1" foam siding that I cover the sump with. this greatly reduces my evap and you can see a HUGE difference in the amount the heaters run. I have 1000 watts of heaters in the sump controlled by my Medusa controller.
BTW, my sump is a 150 gallon rubbermaid tub with about 50-75 gallons of water in it at all times.
here is the graph from summertime so you can see how much my chiller runs. this is from July 9-July 11 2012. Each peak marks the chiller going on and running into the next valley. The medusa kicks it on at 79.1 and runs it down to 78.
Here is the graph for the heat. Valleys mark when heat kicks on. Peaks it turns off. I dont have the Foam cover installed.
