I ordered a fan for my Hovabator. I'm not completely happy with the Hovabator. The thermostat doesn't regulate temps well enough. If the house gets cold at night, the temp in the Hovabator drops. The thermostat should keep a constant temperature, but doesn't. If the system is to click on at the temp you set it for during the day, it should keep the temp at night with a ten degree drop. I installed the aftermarket fan after starting eggs this morning. The temp was right around 100 when I left. I came back about an hour later, after the fan was running, and WOWZER, the thermometer read 120 degrees! So warning- don't trust the thermostatic control to keep the temp where you set it, and be aware that a fan could throw your temps really high! Hope my day one eggs survive!