Best Answer: BTU is an old fahioned term British Thermal Units and was used to calculate the amount of energy required to raise the temp of a room by a degree (using Therms as a unit here too), and is uses an energy calculation rather than a straight how much air does it push sort of calculation.est Answer: BTU is an old fahioned term British Thermal Units and was used to calculate the amount of energy required to raise the temp of a room by a degree (using Therms as a unit here too), and is uses an energy calculation rather than a straight how much air does it push sort of calculation.
Buses that primarily operate service within the city, but are not limited to this area. Local bus service varies depending on the route, but many run seven days a week and nearly 24 hours a day.
List of bus routes in San Diego. From Wikipedia, the free encyclopedia. The San Diego Metropolitan Transit System (MTS) operates a total of 93 bus routes throughout the urbanized area of San Diego and the rest of the southern half of San Diego County, as of January 2015.