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

Overview1. Introduction2. Condensate recovery3. Chilled water usage4. 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 testingSensitivity analysis and uncertainty analysisProjection for other campus buildingsFeasibility 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 CostMcCallum Building $ 25,000

Kaul Building $ 16,000Zeigler Building $ 5,500

Tinsley Harrison Tower $ 2,500Bevill Building $ 30,000

Resreach Support Building $ 25,500Volker Hall Tower $ 24,000

Wallace Tumor Institute $ 20,000Total $ 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!!!