Line voltage thermostats are installed in a series with a single stage conditioning system on a 120V or 240V line. Electricity flows through the thermostat to the system allowing the thermostat to complete or break the circuit based on room temperature. Typically they control a zonal heating system, but can occasionally control a central electric furnace. This measure specifies two thermostat types Electronic Line Voltage Thermostats (ELVTs) and Line Voltage Communicating Thermostats (LVCTs).
There are a few ways ELVTs and LVCTs could save energy, though these savings are not confirmed and the measure is planning. All ELVTs may reduce deadband and reduce drop while some offer programmability. LCVTs could save energy through connectivity and on-board occupancy sensors or geofencing, though the later is not incorporated into into proposed savings estimate due to lack of data.
This measure is Planning. The proposed research strategy aims to estimate savings as a percent of total heating energy for whole-building thermostat change-out in homes with electric resistance zonal heat, determine the average number of thermostats installed in homes with electric resistance zonal heat, and survey retail purchasers of ELVTs/LVCTs to determine the current practice mix and installation practices.