Big Ten Sustainability Conference
November 15-16, 2010
Energy Efficiencies in
Preventative Maintenance
Topics
• Steam Trap Testing
• Synchronous Drive Systems
• Machine Alignment
• Vibration Program
• High Capacity Filters
Energy Efficiencies in Preventative Maintenance
Steam Trap Testing
Problems with Steam Traps
– 5% per year average failure rate of the trap population
– Live steam escapes to condensate system or drain line
– Thousands of $$ wasted due to failed taps
• At Penn State where the current billable rate for steam is
$21.59 per thousand pounds, a failed steam trap on a 15 psig
steam line will waste $5800 per year
Energy Efficiencies in Preventative Maintenance
Steam Trap Testing
Methods for Checking Traps
– Visual Observation – Requires test valve, and the
tester must know the difference between flash
condensate and live steam
– Sound Method – Ultrasonic listening device is used
to listen to the action of the trap
– Temperature Measurement Method – Temperature
sensing device is used to measure the temperature
differential on the inlet and outlet of the trap
We have a testing crew at PSU
Energy Efficiencies in Preventative Maintenance
Synchronous Drive System
 What are they?
 Notched or cogged sheave and belt system
 Used on supply and return fans
3 V-Belt Drive System
Energy Efficiencies in Preventative Maintenance
Synchronous Drive System
Synchronous Drive System
Benefits of Synchronous Drives
– Lower noise level (up to 19dB)
– Vibration reduced by as much as 19%
– 98% efficiency rating (5% higher than typical v-belt
drives)
– Last longer than typical belts
Energy Efficiencies in Preventative Maintenance
Synchronous Drive System
Energy Benefit
– Cost to operate 25 HP motor per year(24/365) with 3 V-Belt
Drive and $0.07 per KWH: $12,496
– Cost to operate as above with Synchronous Drive: $11,829
– Savings per year: $667
– Incremental Cost of retrofit - $850
– Less than 1.5 year payback
Energy Efficiencies in Preventative Maintenance
Machine Alignment
Types of Misalignment
– Parallel Offset
– Angular Offset
– Combination Parallel and Angular
Energy Efficiencies in Preventative Maintenance
Machine Alignment
Contractor Installation (as found)
– 40 Hp Centrifugal Pump
Installation
– 480 Volt Electrical System
– Combination of both Parallel and
Angular Misalignment
• 60 mils (0.060 inches) Parallel Offset
• 40 mils (0.040 inches) Angular Offset
Energy Efficiencies in Preventative Maintenance
Machine Alignment
PSU Installation (after adjustment)
– Both Parallel and Angular Misalignment
Within Specification
• 5 mils (0.005 inches) Parallel Offset
• 5 mils (0.005 inches) Angular Offset
– Measured 1 amp reduction on each leg at
full load
– Power Reduction ~ 831 Watts
– Save 7,282 KWh per year ~$500/year (less
than 1 year payback)
– Extends life of equipment
Energy Efficiencies in Preventative Maintenance
Vibration Program
• PSU Program currently monitors ~800 critical assets.
– Chillers, cooling towers, larger AHUs, exhaust fans and pumps
• Benefits
– Helps us transition from reactive to predictive maintenance by
providing an early indication of machine failure.
– Allows ample time to plan and coordinate an equipment shutdown
instead of an emergency repair situation and the associated
occupant inconvenience.
– A minor benefit is reduced energy loss associated with vibration
Energy Efficiencies in Preventative Maintenance
Vibration Program
• Photograph of a vibration sensor (an accelerometer
with an integrated wireless transmitter and a
mechanical vibration harvesting (piezoelectric) power
supply mounted on a centrifugal chiller)
Energy Efficiencies in Preventative Maintenance
Vibration Program
Outdoor Wireless Receiver
Indoor Wireless Receiver
•Outputs monitored centrally
•Real time actionable data available
Energy Efficiencies in Preventative Maintenance
Air Filtration
Evaluating a filter switch
– Current standard: 2 inch pleated filter
– New filter is a High Capacity 4 ply polyester panel
filter
• Higher initial cost: $2 per filter (24”x24”)
• Lower energy cost: $11 per filter per year
• Lower pressure drop initially and over life
– Reduces frequency of the change outs
• Higher efficiency reduces coil fouling and improves
heat exchange efficiency
• Moisture resistant
• Treated with biocide
Energy Efficiencies in Preventative Maintenance
Energy Cost Comparisons
One(1)
24”x24”x2”
Pleated Filter
Energy
Consumption
(KWh/Yr)
Annual Energy
Cost
CO2 Emissions
Saved (Lb/Yr)
Standard
Capacity
2,361
$165.27
0
High Capacity
2,201
$154.09
219
Energy cost calculation assumptions:
24/7/365 operation, $0.07/KWh energy cost, System air Flow is 2,000 cfm,
Fan/Motor/Drive efficiency total 58%
Standard Capacity Filter Average dP (0.665 in H2O)
High Capacity Koch XL8-HC Filter Average dP (0.62 in H2O)
CO2 Emission:
National average emission factor for electricity is 1.37 Lb CO2 per KWh
Energy Efficiencies in Preventative Maintenance