1. Marriott Corporate Headquarters
John Henderson
Marriott Corporation

2. Marriott Headquarters
1977 construction of ~700,000 square feet
1986 addition of ~300,000 square feet
8 floors including basement
Office space operates 7 am to 6:30 pm
Many areas at ~10% operation 24 hours a day, 7 days a week

3. Marriott Headquarters HVAC & Lighting Equipment in 1989
One 900 ton & one 750 ton electric centrifugal
R-11 refrigerant, 0.86 & 0.92 kW/ton efficiencies
installed in 1977 with original building construction
Two 450 ton chillers, 0.62 kW/ton, R-11, circa 1986
Two 1000 ton cooling towers
Two 350 horsepower gas boilers, 175°F hot water
~12,000 fluorescent fixtures, two 40 watt U-tubes each ~1800 assorted incandescent lamps & spots

4. Marriott Headquarters Project Scenario
boiler room
Virtually no maintenance since 1977
Half of plant didn’t work
Parts leaked, made noise
Not meeting safety requirements
Not providing building comfort

5. Marriott Headquarters “Before” Pictures
air handler unit
sample motor

6. Marriott Headquarters Project Challenges
Everything needed attention at once
Large budget for the wrong things
Set strenuous daily goals
Conserved energy wherever possible
Considered many new systems
Most work and analysis done in-house

7. Marriott Headquarters System Solutions
Short term, through 1994
cleaned up boiler room
rehabbed equipment - motors, boilers, piping, air handlers, etc.
converted all chillers to R-123
increased cooling tower capacities to 1200 tons
added heat exchanger for free cooling
put electronic ballasts in lighting fixtures

8. Marriott Headquarters System Solutions
Long term, 1994 until today
two new traditional chillers, an ice chiller and a gas/oil absorber
redesigned chilled water piping for more effective primary/secondary loops
added window films
extensive rebalancing of air handlers
new motors added
new control system added

9. Marriott Headquarters Variety of New Chillers
One 670 ton electric centrifugal chiller
replaced 900 ton chiller
0.53 kW/ton efficiency, R-123 refrigerant
One 530 ton combination gas/oil-fueled absorber
replaces 750 ton chiller, used for peak shaving

10. Marriott Headquarters Variety of New Chillers
One ice chiller and storage system
converted from 450 ton chiller
2400 tons of ice, or 350 tons of regular cooling, 0.68 kW/ton efficiency, R-123 refrigerant
One 400 ton electric centrifugal chiller
replaced 450 ton chiller
0.53 kW/ton efficiency, R-123 refrigerant
Total of 1950 tons of total cooling capacity, versus 2550 tons previously
ice chiller
ice tank

11. Marriott Headquarters Free Cooling
Condenser water from cooling towers can bypass the chillers
Cooling towers have variable frequency drives
Up to 500 tons of cooling provided
Used during mild weather in spring and fall

12. Marriott Headquarters Cooling Load Reductions
Replaced magnetic ballasts of fluorescent lighting with electronic ballasts
Added tinted films to windows - block sunlight to reduce solar heat gain
Complete balancing of air distribution system, including exhaust system
EnergyStar printers - used sleep mode to reduce energy use

13. Marriott Headquarters Cooling System Improvements
Just finished adding new motors to air handlers
efficiency improved from 87-89% to 94-95%
New EMS system
Andover 1986 model combined with 1994 model
computerized control, and help deciding what systems to run when

14. Marriott Headquarters Project Timeline
New facility management in 1989
Plant clean-up began right away and took 18 months
Plant retrofit work began in 1991
Lighting work in 1992
Window work & AHU balancing in 1994
New chillers installed in 1994
1 year of construction
New AHU motors added in 1998

15. Marriott Headquarters Financing Structure
Won 1st place ENCOMP award in 1992 for large buildings - got us noticed
$1 million from Maryland Public Service Commission through Washington Gas
paid for gas absorber
$1 million rebate from Pepco
replaced one chiller, lighting retrofits, added window films
Sold one 450 ton R-123 chiller
Saved money by using in-house labor
Used almost no cash to finance the project

16. Marriott Headquarters “After” Pictures
boiler room today
color coded piping

17. Marriott Headquarters Project Results
Safe, clean, highly efficient plant
Remarkable system innovation & flexibility
Reduced peak cooling capacity
Much improved tenant/building comfort
No longer using CFC refrigerants
first CFC conversion to R-123
Saving 1.8 MWhrs of electricity per year