Thermostat configured for providing building envelope analysis and method thereof

A method for analyzing a building envelope, comprising:

• calculating a thermal decay time (TDT) at least partially based on:
• an equipment off time during a temperature control equipment work cycle, an ambient temperature, a set point temperature of a thermostat, and a set point dead-band of the thermostat;
• calculating at least one of:
• a building load factor (BLF) under a calm condition at least partially based on the TDT, and a BLF under a windy condition at least partially based on the TDT;
• calculating a normal BLF for a calm condition as a function of building insulation and stack effect;
• and
• analyzing the building envelope for at least one of:
• a quality of building envelope insulation, and whether the building envelope is leaking;
• wherein the quality of building envelope insulation is determined based on the BLF under the calm condition and the normal BLF for the calm condition, and whether the building envelope is leaking is determined based on the BLF under the windy condition and the BLF under the calm condition.

A thermostat, comprising:

• a temperature control module configured for determining:
• an equipment off time during a temperature control equipment work cycle, an ambient temperature, a set point temperature of the thermostat, and a set point dead-band of the thermostat;
• a computing module configured for calculating a thermal decay time (TDT) at least partially based on:
• the equipment off time during a temperature control equipment work cycle, the ambient temperature, the set point temperature of the thermostat, and a set point dead-band of the thermostat;
• the computing module further configured for calculating at least one of:
• a building load factor (BLF) under a calm condition at least partially based on the TDT, a BLF under a windy condition at least partially based on the TDT, and a normal BLF for a calm condition;
• and
• a building envelope analysis module configured for analyzing a building envelope for at least one of:
• a quality of building envelope insulation, and whether the building envelope is leaking;
• wherein the quality of building envelope insulation is determined based on the BLF under the calm condition and the normal BLF for the calm condition, and whether the building envelope is leaking is determined based on the BLF under the windy condition and the BLF under the calm condition.