Rules of Thumb

 Standard lighting retrofits: $0.90-$1.20 per square foot.  High-efficiency packaged and split system A/C equipment: $100$180 per ton more than standard efficiency models.  Premium Efficiency Motors (incremental costs vs. standard replacements): about $16 per horse power (HP) for 1 HP-10 HP motors; $8/HP for 11 HP to 100 HP.  Variable frequency drives (VFDs): $150$200, installed.  Commissioning new buildings: $0.50-$3.00 per square foot.  Retro-commissioning buildings: $0.05 and $0.40 per square foot.  Existing buildings: overall consumption reductions of 20% to 30%, with reductions as high as 35%-40%, depending on aggressiveness.  Retro-commissioned commercial building: average savings of 1.7 kWh/ft and average overall energy savings of 15%.  Lighting retrofits: save 10%-20% of total electric consumption in gas-heated buildings.  High efficiency packaged and splitsystem cooling equipment: 25% less cooling energy than standard equipment and 10%-15% less than ASHRAE standard.  Building Operator training: 0.35-1.2 kWh/ft per year.  Existing buildings: reducing consumption by 20% to 30% can produce savings from 6%-9% of total annual costs.  Converting constant volume HVAC systems to variable air volume systems: can save between $0.10/ft to $0.20/ft or 10%-21% of HVAC energy costs.  Installing premium efficiency motors and VFDs: Potential energy cost savings are 50-85%.  Peak energy-reducing measures: produce proportionally greater cost savings than those that have mostly off-peak savings.  Commissioning new buildings: average savings of $0.05/ft.  Retro-commissioning existing buildings: save around $0.27/ft, resulting in 15% energy savings and a payback period of 0.7 years.  Existing buildings: improved comfort and better air quality can increase productivity.  Retrofitted buildings: Increased savings from enhanced productivity can equal up to 10 times the energy cost savings.  Existing buildings: 1% productivity improvements can offset entire annual utility costs.  Existing buildings: For every $1 spent in local economy, energy efficiency generates 57¢84¢ more economic activity than does payment of energy bills.  Existing Buildings: energy efficiency investments can increase asset value by $2.00-$3.00 for each $1.00 spent.  Existing buildings: a lighting power reduction of 40% increases an ENERGY STAR rating by 10 points.  Retrocommissioned buildings: annual non-energy savings, such as extended equipment life and improved air quality, are approximately $0.26/ft.