A flexible public methodology was developed for estimating financial indicators for alternative HVAC equipment in commercial buildings. It is based on simulation of the building's hourly energy use, and it allows for many economic parameters, among which are detailed utility rate structures, fuel price escalation rates, inflation rates, and loan expenses. The methodology was applied to the evaluation of natural-gas-fired engine-driven chillers in large commercial office buildings. This technology was predicted to be promising for buildings located in Chicago, Boston, and San Diego. The electrical rate schedules for these three cities have high demand and time-of-day charges. The initial cost premium for the engine-driven chiller was found to be of major importance.

KEYWORDS: economics, heating, ventilation, air conditioning, offices, buildings, commercial, calculating, energy consumption, tariffs, price, fuels, natural gas, gas fired, engine driven heat pumps, chillers, refrigeration, USA, building services