The recent National Conference on Building Commissioning, sponsored by Portland Energy Conservation, Inc. (PECI), provided some object lessons in how poorly most buildings, even new ones, operate, and what that means in terms of wasted energy and unnecessary carbon emissions.
Take the “deadly sins” of energy waste, as defined by PECI’s Tudi Haasl, one of the pioneers of building commissioning:
1. Equipment running more than needed.
2. Cooling or heating air or water more than needed.
3. Heating and cooling at the same time.
4. Moving too much air or water.
These things happen, even in “good” buildings. Paul Ham, a LEED AP engineer who heads Target Corporation’s energy-conservation program, described the typical “discrepancies” he’s found in the retailer’s 1,600 stores and 32 distribution centers:
· Heat recovery wheels not functioning properly (usually a problem with the belts)
· Economizers not working right (usually incorrect damper positions)
· Incorrect temperature setpoints on equipment
· Lighting occupancy schedules incorrect
· Ventilation requirements not met
· Outside air temperature sensors placed in direct sunlight, making accurate readings impossible
E.J. Hilts, who heads building operations for Marriott International in the western states, says even parking garages can be energy wasters. In retrocommissioning the San Diego Marina Marriott, he found exhaust fans in the garage running 24 hours a day. So he installed carbon monoxide sensors and put the fans on automatic operation.
The result: the fans only came on for a few minutes at a time during morning and evening peaks, with no danger of carbon monoxide poisoning, thanks to the sensors. Annual savings: $59,000, with a commensurate reduction in greenhouse gas emissions.
Hilts says retrocommissioning the Marriott hotels he oversees in the western U.S. alone could result in 5-15% energy savings and send $4-12 million to the bottom line. In hotelier’s terms, that’s equivalent to increasing the number of occupied rooms by 17,000 a year—and that’s just in the West.
In fact, the payoff period for most retrocommissioning projects is usually less than two years—and that doesn’t count incentives from utility companies and tax write-offs.
Here are some useful resources on building commissioning:
Building Commissioning Association, www.bcxa.orgCalifornia Commissioning Collaborative Retrocommissioning Toolkit, EPA Energy Star Portfolio Manager Benchmarking Tool, www.energystar.govNorthwest Energy Efficiency Alliance, BetterBricks, www.betterbricks.comPECI’s “Retrocommissioning Guide for Owners,” www.peci.org/Library/EPAguide.pdf
Two final thoughts on this subject:
1. It’s just as important to implement many “small” conservation measures in existing buildings as it is to get all excited about building a relatively few new zero-carbon buildings.
2. The sooner you make energy improvements in existing buildings, the faster and greater will be the payoff in greenhouse gas reductions. It’s like the “miracle” of compound interest: start now, and the benefits keep compounding over the years.