Fix Leaks and Malfunctions
Leaks and poorly performing equipment can stymie your best efforts to shore up cooling efficiency, so as you give the rest of the system a tune-up, keep an eye out for components that need repairs.
Ductwork leaks, for example, are fairly common, Brookover notes. Unfortunately, this problem is also frequently overlooked unless a sudden leak triggers a significant spike in energy consumption. Sealing duct leaks and restoring the integrity of the unit cabinet can save around 20% of your annual
cooling consumption, FEMP advises.
Common corrective actions including simple screw or latch replacements, patching or replacing gaskets, and replacing missing screws on any loose access panels. The condensate drain pipe may also leak air, so be sure to recharge P-traps or U-bend water traps for condensate drain pans.
If you have an economizer, also check it for malfunctions, which FEMP notes can include a jammed outside air damper; jammed, broken, or disconnected linkage; a nonfunctioning actuator; or inaccurate air temperature sensors. These issues impair the economizer’s ability to sense and respond to the temperature of the outside air vs. return air.
Additionally, an economizer that’s not operating properly can actually waste energy. If the outside air damper is stuck open, the HVAC system has to work harder to heat or cool the excess outdoor air.
FEMP recommends a twice-yearly test of economizer function using the following three steps:
- When the system is mechanically cooling, make sure the economizer is using minimum outdoor air settings.
- Cycle the minimum position potentiometer from 0 to full open. Watch the damper to make sure it can operate freely and without obstruction the entire time.
- On a cool day when the damper is open, warm the outdoor air temperature sensor with your hands or an electric hair dryer to see if the damper moves to its minimum position. If it doesn’t, you might need to recalibrate the sensor or deal with malfunctioning economizer controls.
Got another tip? Email it to
janelle.penny@buildings.com – your advice could end up in a future issue.
Janelle Penny janelle.penny@buildings.com is associate editor of BUILDINGS.