A common misconception is that building energy use can be optimized by replacing aging, inefficient HVAC and electrical equipment with modern, more efficient models. While replacing equipment can provide energy savings, true energy optimization can only be achieved through an integrated approach that will first promote a reduction in mechanical and electrical demand.
Upgrading an existing building’s envelope by reducing infiltration and installing additional insulation, high performance windows, and shading devices will all reduce demand. For new construction, site orientation can take advantage of passive solar heating, natural ventilation, and daylighting. For new construction and retrofit projects, using natural energy via photovoltaics, solar thermal systems (hot water), and wind power provide opportunities for off-the-grid energy.
An often overlooked component of energy use is plug loads, which typically includes computers, coffee pots, copiers, refrigerators, and other miscellaneous devices typical of an office environment. Laptop computers use significantly less power than console and monitor systems. Unplugging appliances that are not in use and using Energy Star compliant devices are just two easy ways to help reduce phantom energy – defined by Wikipedia as “the electric power consumed by electronic appliances while they are switched off or in a standby mode.”
Once the mechanical and electrical energy demands have been reduced to the greatest extent feasible, new equipment can then be addressed. The reduced demand will allow smaller replacement equipment with lower first-costs. Equipment closely matched to demand operates more efficiently. Furthermore, high efficiency equipment is the preferable option compared with equipment that only meets the minimum industry standards. Systems that use renewable energy sources, such as geothermal and active solar systems, are also sound choices.
This integrated roadmap for reducing demand and then applying high efficient equipment is a sound path to optimizing energy use.