<p>Oh, wow, another example of a freeloader! Good luck with that. </p>
<p>You could also look into an energy meter to figure out the amount of kWh used by the roommate’s electric heater. However, it’s based on honesty system since the roommate can easily remove the device. Maybe, he can put a tamper-proof casing over it.
<a href=“http://www.smarthome.com/p3-international-p4400-kill-a-watt-energy-meter.html”>http://www.smarthome.com/p3-international-p4400-kill-a-watt-energy-meter.html</a></p>