CUSTOMER: Full Service Sheraton
LOCATION: Fort Lauderdale, FL
INDUSTRY: Hospitality
AIRREVIVE SERVICE: Fan coil unit refurbishment and control valve replacement
FAN COIL UNITS: 1989 IEC Vertical Fan Coil Units
Fan Coil Unit Refurbishment and
Control Valve Replacement
Case Study
Refurbishing 26-year-old IEC units to operate as new
This full service South Florida landmark selected AirRevive to restore its two-hundred and sixty-four 1989 IEC guest room vertical fan coil units during its multi-million dollar renovation.
This study compiles data collection on the following:
Mouse over to go directly to each section.
I. Project Goals and Scope of Work
II. Coil and Supply Temperature
III. Airflow
IV. Sound
V. Project Summary
VI. Facility Benefits
I. Project Goals and Scope of Work
PROJECT GOALS
1. All HVAC units should be repaired/reconditioned to like-new condition. This will include:
- Thoroughly cleaning coils.
- Insuring cabinet and piping insulation is intact.
- Insuring proper cooling valve and heating coil operation.
- Insuring proper fan operation that is quiet and will not disturb guests.
- A maximum of a 55 degree F discharge cooling temperature shall be achieved.
- A minimum of 90 degree F discharge air heating temperature shall be achieved.
2. If any of these conditions cannot be met, individual components or the entire unit may have to be replaced to obtain an acceptable level of performance.
FAN COIL UNIT REFURBISHMENT AND CONTROL VALVE REPLACEMENT:
- Replace fiber insulation with fiber-free foam anti-microbial thermal insulation
- Deep clean coils and fins from the back side and the front side
- Remove all debris from the blower assembly, motor, and wheel
- Clean and disinfect the blower assembly, motor, and wheel
- Replace malfunctioning and leaking-by control valves
- De-rust condensate pan and re-coat with impermeable epoxy
- Clear out, clean and disinfect the drain line
- Replace air filter
Coil Temperature Before and After Service
Summary: Coil temperature dropped by an average 10.5℉ from 60.2℉ to 49.7℉.
The graph below shows coil temperature sorted from high to low before coil rejuvenation.
The red line shows that before the coils were rejuvenated the coil temperature ranged from 73.8℉ to 46.1℉. The average coil temperature was 60.2℉. The coil temperature was above 54℉ on 88% of the units.
The blue line shows that after the coils were rejuvenated the coil discharge temperature for 98% of the units is below 55℉. The average coil temperature after service is 49.7℉.
Supply Temperature Before and After Service
Summary: Supply temperature dropped by an average 5.2℉ from 62.3℉ to 57.1℉.
The graph below shows supply temperature sorted from high to low before coil rejuvenation and control valve replacement.
The red line shows that before the coils were rejuvenated the supply temperature ranged from 74℉ to 57℉. The average supply temperature was 62.3℉. The supply temperature was above 60℉ on 86% of the units.
The blue line shows that after service the supply temperature for 96% of the units is below 60℉. The average supply temperature after service is 57.1℉.
III. Airflow
FPM Airflow Before and After Service
Summary: Airflow increased from an average of 670 FPM to an average of 910 FPM.
The graph below shows high fan airflow from the bedroom supply vent measured in FPM sorted from low to high before the coil rejuvenation.
The red line shows that before service the high fan airflow ranged from 208 FPM to 1024 FPM. Average airflow was 670 FPM.
The blue line shows that after service the high fan airflow ranged from 553 FPM to 1185 FPM.
Overall the coil rejuvenation increased the airflow by an average 27% from 670 FPM before service to 910 FPM after service. In all units airflow was unrestricted.
IV. Sound
Sound Decibels Before and After Service
Summary: Sound decibels reduced from an average of 60.79dB to 56.65dB.
The graph below shows sound decibels measured from the bedroom supply vent sorted from high to low before service.
The red line shows that before service sound decibels ranged from 76.1dB to 53.6dB, averaging 60.79dB.
The blue line shows that after service sound decibels ranged from 65.2dB to 52.1dB.
Overall the service reduced sound decibels by an average 7% from 60.79dB before service to 56.65dB after service. After service 97% of the units sound measure below 60dB or less. 60dB is the acceptable measurement for new units.
IV. Project Summary and Facility Benefits
RESULTS SUMMARY
- The coil temperature dropped by an average 17.5% or 10.5℉ from 60.2℉ to 49.7℉
- The coil discharge temperature before service was above 54℉ in 88% of the units. After service the coil discharge temperature is below 55℉ in 98% of the units.
- The supply temperature dropped by an average 8% or 5.2℉ from 3℉ to 57.1℉.
- The supply temperature before service was above 60℉ in 86% of the units. After service it is below 60℉ in 96% of the units.
- Airflow increased by an average 27% from 670 FPM to 910 FPM.
- Control valve replacement eliminated simultaneous cooling and heating.
- Sound decibels reduced by 7% from 60.79dB to 56.65dB.
- The coil rejuvenation resulted in unrestricted airflow in 100% of the units.
- The result of more efficient heat transfer combined with increased airflow is faster guest room cooling and heating.
- The thermostat is satisfied quicker i.e. reaches accurate temperature set points quickly.
- The water temperature delta between the supply and return was narrowed.
- Greater guest comfort and satisfaction resulting from improved indoor air quality and units that achieve temperature set point quickly.
FACILITY BENEFITS
The project resulted in the fan coil units performing more efficiently. The benefits to the facility are the following:
- The facility saves energy in the guest room by the thermostat being satisfied faster which reduces fan motor run-time.
- The facility saves in labor and expenses by eliminating FCU related customer service calls and malfunctions.
- The facility saves energy at the chiller by:
- Reducing the work required at the guest room level to maintain temperature set point which runs the chiller less; and
- Reducing water supply and return temperature delta results in less work for the chiller to maintain the loop temperature set point.
- The indoor air quality is improved in all guest rooms.
- The guest rooms cool and heat faster and maintain temperature set point; and
- Improved guest comfort and guest satisfaction by properly functioning HVAC units.