Case Study of Condensate Recovery and Its Reuse at The University of Alabama at Birmingham Presented by Atul Kajale Dr. Robert W. Peters, Ph.D., P.E. Mr. Matt Winslett Alabama Water Resources Conference 2013 Orange Beach, AL September 5-6, 2013
Mar 29, 2015
Case Study of Condensate Recovery and Its Reuse at The University of
Alabama at Birmingham
Presented by
Atul Kajale
Dr. Robert W. Peters, Ph.D., P.E.
Mr. Matt Winslett
Alabama Water Resources Conference 2013
Orange Beach, AL
September 5-6, 2013
Overview
1. Introduction
2. Condensate recovery
3. Chilled water usage
4. Results
5. Discussion and Conclusions
Introduction
Condensate Recovery: Recovery of the condensate water produced from the air handling units (AHUs) and its reuse in processes where non-potable water is required.
Condensate Recovery Systems (CRS) in new constructions and in existing buildings.
Uses of condensate water- for irrigation, flushing toilets, reuse in chilled water plants
Southeastern states have potential of capturing more than 15 gallons per cfm of air [Lawrence and Perry, 2010].
Introduction
Research done in co-operation with the Energy Management Division of the Facilities Management Department at the University of Alabama at Birmingham (UAB)
CRSs in seven campus buildings
Laboratories, and research buildings use- 100% outside air
Pipes, joints/connectors, water storage tanks (100-500 gallons), pumps, floating devices, filters, and water - meters.
Condensate Recovery
Figure 1. Condensate Collection Potential in United States. [Lawrence and Perry, (2010)]
Drought Condition
August, 2012 December, 2012 August, 2013
Condensate Recovery at UAB
Figure 2. Schematic of the Condensate Collection System at UAB.
Condensate Recovery at UAB
Figure 3. Condensate Recovery System at UAB: Small storage tank, 500-gallon storage tank
Condensate Recovery at UAB
Condensate from each 500-gallon storage tanks is
measured by a water - meter
Condensate production in 4 AHUs is continuously
monitored and recorded in real-time using HOBO-
U20 water level dataloggers
Change in water level, temperature, and pressure.
Condensate is fed to the chilled water return pipe
Temperature of condensate (53⁰F-73⁰F)
Condensate Recovery at UAB
Main objectives of the study:
Develop a multiple regression model to analyze the effect of indoor and outdoor operating conditions.
Model validation, hypothesis testing
Sensitivity analysis and uncertainty analysis
Projection for other campus buildings
Feasibility analysis and applicability for other locations in Alabama.
Condensate Recovery at UAB
Table 1. Detailed Cost of Condensate Recovery System at UAB
Building Name Installation Cost
McCallum Building $ 25,000
Kaul Building $ 16,000
Zeigler Building $ 5,500
Tinsley Harrison Tower $ 2,500
Bevill Building $ 30,000
Resreach Support Building $ 25,500
Volker Hall Tower $ 24,000
Wallace Tumor Institute $ 20,000
Total $ 150,000
Results
3 chilled water plants serve 52 campus buildings.
Make-up water demand and cost
Figure 4. Water demand of UAB Central Chilled Water Plant
Results
Year Water in gallons2012 (12 months) 3,232,9622013 (7 months) 2,128,719
Figure 5. Condensate volume recovered at McCallum and Tinsley Harrison Tower
Results
Figure 6. Condensate volume recovered from six condensate recovery systems
Results
In 2011, total water demand was 311,00 CCF and the cost $2,170,000.
In 2012, total water demand was 310,199 CCF and the cost $1,960,075.
More than 7 million gallons of water was captured and reused in 2012.
5.7 million gallons of condensate is captured in 2013 till the end of July.
12.7 millions gallons accounts for $54,500.
This accounts for 5% of water demand and 2.7% of associated cost
Results
The peak condensate recovery during summer was 4.38 gph/1000 ft2.
Average condensate was is 6 times higher than predicted by Guz’s study (2005).
The minimum and maximum hourly condensate volumes ranged from 0 to 230 gph.
12.7 millions gallons of condensate recovery accounts for $54,500 of savings.
Average payback period of 3 years for the entire project.
Discussion
Advantages of reuse of condensate water in chilled water plants:
Lowers the water demand of the chilled water plant.
Efficient use of potable water.
Temperature of condensate varies between 53 ⁰F and 74 ⁰F whereas the temperature of municipal water is 81 ⁰F.
Feasibility: water savings, energy savings, and sewer cost
Discussion
Majority of the southeastern United States is prone to drought condition and hence conservation of water is very important.
Hot and humid weather is favorable for successful condensate recovery.
There is great potential for water conservation in commercial, industrial, and institutional buildings.
CRS at UAB have shown significant collection of condensate
Indicating opportunity to install more systems across the campus buildings.
Acknowledgement
Energy Management Division of Facilities
Management Department at UAB
Sigma Xi Scientific Research Society
Department of Civil, Construction, and
Environmental Engineering at University of
Alabama at Birmingham
Thank You!!!