Techniques for providing ancillary services to a power grid using customer premises such as commercial buildings. The techniques may involve receiving a regulation signal from a grid operator that is specific to a commercial building and modifying power consumption by at least one power consumption component in the building based on the regulation signal. The power consumption component may be a fan of a Heating, Ventilation, and Air Conditioning (HVAC) system. Conducted experiments demonstrate that up to 15% of fan power capacity may be deployed for regulation purposes while maintaining indoor temperature deviation to no more than 0.2° C. The regulation signal may be tracked in a frequency band from about 4 seconds to 10 minutes.