Applying Energy Efficiency

Specifically for buildings, applying energy efficiency means taking a whole-building approach to how energy is consumed.  This process is applicable to buildings of all sizes.

The Whole-Building Approach

Energy within a building is consumed as part of a whole, and changing one element of a building's energy use can impact others.  For example, weatherizing a building by applying air sealing and insulation will reduce the heating and cooling loads.  This, in turn, can enable the use of smaller heating and cooling systems, which use energy more effectively and further reduce the energy load of a building.

Building Envelope

The thermally conditioned area within a building (its envelope) needs to be properly insulated and its air flow controlled before other measures involving air exchange are taken.  This critical step can include modifications to doors, windows, wall or attic insulation, or weatherstripping.

Baseload

Baseload is the consistent energy load of a building, independent of outside temperature (heating or cooling).  It is useful to separate baseload from temperature-dependent loads to identify which energy loads are greatest, and determine where to target energy-reducing measures.  Some contributors to baseload could be appliances, lighting, and cooking equipment.

Heating and Cooling

Depending on geographic location and building use, heating and cooling can be a significant part of a building's energy use.  These loads are directly tied to the performance of the building envelope, and efforts to increase efficiency in heating and cooling often result in a marked improvement in the comfort of a building's occupants.

Energy Sources

When targeting energy reduction with the goal of reducing impact on the earth's climate, it is important to consider which portions of a building's energy comes from fossil fuels.  To produce the biggest impact on carbon footprint reduction, the priority is on the reduction or elimination of fossil fuel consumption, in addition to reducing consumption overall.  It is easier to convert some types of energy (electricity, for example) to renewable sources than others.