Quarters at Cambridge depends on heat pump systems for our heating and cooling needs.  In order to maximize the efficiency of the unit in the colder months, it is recommended that thermostats are set between 68-78 degrees.  Temperature adjustments should be limited to 2-3 degrees, and if you are gone for long periods (vacation, etc.), it is better to leave the thermostat set to the temp range listed above.  Setting it below the 68 degree mark will cause the unit to engage the auxiliary heat system meaning both heating systems are running simultaneously, which actually costs you more money in the long run.  Also, it is best to set the fan to auto, and change the filter regularly (we do this for you!) .  Stay warm and save money!