Concerned that you’re wasting energy? Onset Computer has a tool you might be interested in: the HOBO Temperature Logger Kit. Mac and PC-compatible, the $79 kit lets you develop a profile of household heat and energy usage.
The Temperature Logger Kit combines Onset’s HOBO U10 temperature data logger, HOBOware Lite software and USB interface cable. The U10 is a battery-operated data logger that can record temperature in indoor environments. You can set sampling intervals from one second to 12 hours.
Once you’ve recorded the data you want, the HOBOware Lite software recovers the data (using the USB interface cable) and converts that information into time-stamped graphs.