Measure of gas that contains 100,000 BTUs. As there are approximately 1,000 BTUs per cubic foot of gas, there are approximately 100 cubic feet of gas per therm.


Using, producing, or caused by heat.

Thermal Efficiency

As used by the process heating industry, thermal efficiency is a percentage figured by dividing the thermal energy put into the product by the total thermal energy expended by the process.

Thermal Envelope

The structural parts of a building that enclose the conditioned space and control the heat loss/gain of the building.

Time of Use (TOU) Rates

Lower rates sold on a long-term contract basis to customers with certain load patterns or those who have the flexibility to shift usage to off-peak periods, such as evenings, nights or weekends.