Cool Towers

Project Lead: Sara Shirazi

Sponsor: Physical Plant-Campus Services

TGIF Grant: $10,216

Project Theme: Energy Efficiency & Conservation

Project Location

2013 Application Submission

Status: In Progress

Project Description: Cooling towers are mechanical systems integral to the operation of Heating, Ventilation, Air Conditioning and Refrigeration (HVACR) systems. Cool Towers will hire two student associates to assist PP-CS in the development of a comprehensive cooling tower inventory. The students will identify system type, controls, water treatment type, and chemical usage, as well as an indication of overall water usage, strainer and basin health of the cooling towers. PP-CS will use the data to identify water and energy conservation opportunities and develop a campus-wide standard for future cooling tower installations and retrofits.

Goals: Once field data has been collected, the team will work with PP-CS to identify water and energy conservation opportunities. This includes performing lifecycle analyses on case alternatives as well as working with vendors to develop cost estimates. It is also the intent of this project that a campus-wide standard can be developed so all future cooling tower installations and retrofits will be able to use a "Cool Towers" standard, one that is enforceable by PP-CS Engineering Services and Energy Office.

With a campus of over 100 buildings and 17 million square feet of floor space, UC Berkeley faces a significant heating and cooling demand. While heating relies on a central steam system, cooling requires an individual system in each building. Unfortunately, this leads large-scale cooling systems to be costly, difficult to maintain, and energy inefficient.

2013 Accomplishments

  • The scope of the project was narrowed down to the campus' cooling tower systems
  • Project leaders designed a standard reporting format for the cooling tower data.
    • The sections of this report include an overall system description, a schematic, the cooling tower specs, the chiller specs, the water pump specs, cooling tower condition, and chemical treatment data.
  • Project leaders performed field surveys for 72 campus buildings, which included 234 separate heat exchangers and over 500 water pumps for both the heating and cooling systems.
    • This data collected will be used to fix incorrect data and improve the state of the preventative maintenance program.
    • The collected data also serves as a stepping-stone for future financial savings and resource conservation.

Summary of Data Collected

  • Project leaders created a schematic for every single cooling tower system on campus, collected detailed manufacturer data and chemical treatment data, and assembled it all into one large binder. The data inside includes:
    • 50 unique cooling towers, totaling at over 35000 gallons per minute of flow capacity
    • 50 chillers
    • 200+ motors, totaling at over 4000 Horsepower of combined power

Cooling Tower Operation

  • Hot water enters through the pipe on top of the tower
  • Water is equally distributed within the tower with a sprayer
  • Water drips down packing, losing heat due to evaporation

  • Eliminators prevent water from escaping
  • Fan removes heat from tower

  • Cold water collects in the basin, and is pumped out to cool the building

Current Sustainability Issues

  • There are a number of towers on campus near or at the end of their lifespan. Damage and dirt accumulation in a tower, caused by age and improper maintenance, is not only bad for the tower, but risks harm to other equipment and people. These risks include:
    • Irreversible damage to chillers and heat exchangers due to chemical deposits and corrosion. Replacement can cost upwards of 1 million dollars.
    • Severely reduced system efficiency. More water needs to be pumped through the tower to remove the same amount of heat, and thus water and energy are wasted.

    • Spread of diseases. Bacteria, algae and mold can all grow in improperly treated Cooling Towers, and enter building airways. The most infamous of these is Legionnaire’s disease, which has been responsible for hundreds of infections and deaths.

Final Report

Future Steps

  • Fortunately, these risks are entirely preventable by simple preventative maintenance. Now that the campus’s engineers have access to a binder of all the essential cooling tower information, they will know exactly how to maintain the towers.
  • Berkeley has already used this data to approve a redesign of Koshland Hall’s cooling system, which could save up to 7 million gallons of water per year.  With this degree of savings, the new system will pay for itself in less than 10 years.  Hopefully, these savings will provide the motivation for funding  the replacement of equally inefficient, wasteful systems.

Mission Statement

The Green Initiative Fund (TGIF) provides funding for projects that reduce UC Berkeley's negative impact on the environment and make UC Berkeley more sustainable. TGIF will allocate funds to projects that promote sustainable modes of transportation, increase energy and water efficiency, restore habitat, promote environmental and food justice, and reduce the amount of waste created by UC Berkeley. Portions of the fund also support education and behavior change initiatives, student aid (via return to aid), and internships. TGIF is supported by student fees and administered through a student-majority committee and a program coordinator.