Below is information provided by Jeremy Overmann, B.S. Ch. E., Water Treatment Specialist, on the water use and cycles of concentration (COC) in a cooling tower, as requested after a Land and Water SWAT meeting. 

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Water SWAT members,

Here is some more information regarding the cooling tower discussion at today’s meeting.

This first graph shows how much water a typical 100 ton Cooling Tower uses per hour, and how this changes when the tower is operated at various Cycles of Concentration (COC)

NOTE:  a 1 ton cooling tower can remove 15,000 BTU/hr of heat.

Most standard chemically treated Cooling Towers use unsoftened water and operate between 4 – 6 COC, depending on the source water quality (also called Make-Up water) and the efficacy of the chemical treatment program.

As COC increases, the potential for formation of calcium scale (and possibly other types of scale) increases.  Scale deposits reduce the energy efficiency of the chiller and the cooling tower, and result in the need for labor intensive cleaning to remove the scale.

The following table shows the relationship between volume of Cooling Tower blowdown (bleed), blowdown rate (% bleed), COC, and total water usage.

Cycles of Concentration is controlled by choosing the rate of blowdown.  This is done by controlling the blowdown (bleed) valve at the bottom of the tower.

In a “Zero” blowdown cooling tower, softened water is used, and cycles of concentration ranges from 20 – 100 or higher.  To achieve proper water chemistry to provide corrosion protection, usually need to operate at > 20 COC. 

During the Champaign Regional Office Building study, the highest COC achieved was 51.  The blowdown valve is turned off, however some water is lost from leaks in the tower, and from droplets of water that escape with the air that is drawn through the tower.

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The University pays a stormwater utility fee to both the City of Urbana and the City of Champaign.  The fee is based on total impervious area that drains into city-owned storm sewers. If stormwater drains into university-owned sewers then directly discharges to a receiving stream, there is no fee assessed.

• The current rate for the City of Champaign is $5.24/3,478 sq ft.
• The current rate for the City of Urbana is $5.14/3,100 sq ft.

There are credits and incentives that the university can apply toward the stormwater utility fee. By maintaining compliance with the university’s Municipal Separate Storm Sewer System (MS4) National Pollutant Discharge Elimination Systems (NPDES), the university receives a 5% credit from each city. Additionally, each city has their own Credit and Incentive Manual (attached) which provides an opportunity for the university to reduce their stormwater utility fee by reducing the impact of the runoff from their properties by methods such as installing sustainable storm water practices that allow stormwater to infiltrate into the ground. The manuals have specific guidelines on how to calculate the credits based on the particular stormwater practices that are employed.

Hi Solar UC Advisory Committee,

The Midwest Renewable Energy Association (MREA) has accepted the Solar Urbana-Champaign Advisory Committee’s recommendation and contracted with New Prairie Construction to install solar arrays for the second round of our group buy program.  MREA and New Prairie Construction have agreed to an amended fee schedule whereby New Prairie will be providing a rebate which will be paid to program participants who sign a contract for services by August 31, 2017 according to the following schedule: $.03/watt if the program reaches 50-150 kW of total capacity; $.06/watt for 150-250 kW; $.09/watt for installed capacity in excess of 250 kW. 

Please keep an eye on solarurbanachampaign.com as we will be announcing Solar Power Hours very soon.  Please share these event announcements through your networks and let us know of any ideas for additional public engagement.

Thanks!

Scott

Scott R. Tess

Environmental Sustainability Manager

City of Urbana, IL

P: 217-384-2381   -   F: 217-819-3167

706 S. Glover Ave. Urbana, IL 61802

Walk Score® – 61 out of 100

Bike Routes – www.urbanaillinois.us/bike-urbana

Plan Your Bus Trip – http://www.cumtd.com or 384-8188

Diliya Murtazina and Morgan Johnston reviewed the work tasks completed this year, and identified files to finalize for the end of this project. Diliya will formalize the behavior change strategies document, collect all the example images, and provide documentation on the creation of the building level energy charts with examples.

The new Zero Waste Coordinator started work on March 13.

A main component of the 2010 iCAP is to engage the outside community in working to create a more sustainable campus. The University of  Illinois is working to enhance its engagement activities in the arena of sustainability. Champaign County Network (CCNet) is an effort to engage the campus and the surrounding community in a shared discourse on the critical sustainability and climate issues ahead. The University's Office of Corporate Relations is working to enhance collaborations with corporations in sustainability activities.

The iCAP provides an opportunity to engage the outside community in a dialogue on the University’s role in helping to resolve community climate responses. For example, the Smart Energy Design Assistance Center (SEDAC) is designed to provide assistance to public and private interests in reducing and conserving their operational energy use in buildings. This type of information is an important step in developing meaningful solutions to climate change.

3/3/17

Summary: This meeting served to update and refocus the team, as well as to further discuss Lily Wilcox’s suggestion for her bike-cage recommendation.

In attendance:

Josh Feldman

Morgan Johnston

Brian Farber

Pete Varney

Lily Wilcox - Active Transportation Coordinator

Topics Covered:

New IWG chair – Ximing Cai

Ben McCall has stepped down as the iCAP working group chair and will be replaced by Ximing Cai, who will start on March 1st. Morgan Johnston will serve as the interim chair until then. Ximing wants to tie iSEE to other campus sustainability programs better, and wants faculty outside of iSEE more involved.

IWG wants recommendations

The iCAP working group is asking for feedback as to how well recommendations are working from our perspective. They hope to have a summary for recommendations by May. For instance, you might note that it is hard to have faculty engagement, or that the SWATeam isn’t getting enough feedback. If you have suggestions you would like IWG to hear, email Morgan Johnston.

Bike Parking Cage proposal

Last semester, Lily Wilcox introduced a suggestion to have secure cages for bike storage in all new parking structures. Those who would like to use these structures would pay for a permit. The team has not yet decided to agree completely on the proposal as we are still working out how to address some specific concerns.

The most important concern is cost. These cages are expected to cost approximately $60,000, and will be in use for the 30-50 year lifespan of the parking structure. Morgan noted that these cages would likely be in high demand, so we could charge upwards of $85-$100 per year for a permit, similar to universities like Ohio State and Minnesota.

Additionally, we discussed who the primary customers would be. Likely, the primary buyers would be day-riders and some students. Morgan suggested that we talk to campus recreation about the idea as well.

Finally, we discussed some of the implementation challenges of the proposal. Brian mentioned that having bike riders in a parking garage create a safety hazard as cars may not be aware of or expect bike riders. Furthermore, any malfunction of the card-swipe system would be a huge inconvenience for anyone who needs to retrieve their bike.

Overall, we have not yet formally agreed to go ahead with the recommendation but will continue to discuss it until we work out these issues.

Next Meeting

Our next meeting will be Thursday, March 16 at 1pm. This meeting will take place on Thursday so as to not be right before spring break.

Work Request 253325 converted to Work Order 10519389

Work Order: 10519389

Building: 0209 - SPEECH AND HEARING SCIENCE

Room:

Department Reference:

Customer Description:

WO for engineering services for solar funding for Speech and hearing sciences

Phases:

Phase: 001 DESIGN SERVICES