Reducing the overall energy demand of HVAC systems in commercial establishments can be accomplished either by installing new, energy-efficient Energy-Star equipment (which pays for itself over time) or by taking simple steps to maximize the efficiency of existing units.

You can reduce the load on HVAC systems by making sure buildings are well-insulated and well-sealed. Roofing materials that reflect heat (or better yet, "green" roofs - see below) can cut the demand for cooling. Ceiling fans can help circulate cool air or, on slow speeds, move warm air from the ceiling down into the room.

Programmable thermostats can help you regulate temperatures more precisely, and multiple zone HVAC systems will allow you to tailor your energy use to actual need. Replace HVAC filters regularly. Shade south-facing windows in summer to keep direct sunlight out.


Resources:

Business.gov is the "official business link to the U. S. Government" and is operated by the Small Business Administration. A whole section of the site is devoted to energy-efficient HVAC systems.

The U. S. EPA has information for Businesses and Non-Profits to make your small business more energy efficient. They've also created a "Green Power Locator" which can help business owners (or individuals) quickly find sources of "green power" in their state.

Green Roofs for Healthy Cities is a trade association of green roof manufacturers and supporters dedicated to developing the market for green roof infrastructure products and services in North America.