We set COC = 5 for pilot studies.

Meeting Minutes 4/21/17

In attendance:

Ximing Cai

Pete Varney

Brian Farber

Yanfeng Ouyang

Summary:

This meeting serve to continue discussion on campus fleet, bike parking, and campus parking. Also, Ximing Cai was introduced to the team.

Topics:

Discussion on Campus Fleet

Pete led a discussion on campus fleet efforts. He stated that converting campus fleet to EVs and CNG vehicles would have a large effect on campus emissions, and that campus utility is interested in learning about electric vehicles, but there are certain obstacles to converting campus fleet. First it would cost about half a million dollars or more. These costs are largely attribute to building infrastructure for CNG refueling systems. In addition, campus fleet vehicles for Facilities and Services as well as housing do not drive very far, so the fuel savings would be small. However, converting campus fleet would be practical as the vehicles do not travel off campus, meaning there will be no inconvenience in refueling the vehicles.

Bike Parking

We continued our discussion on bike parking from the last meeting. One of our concerns, given the cost of the permits, is security. Anyone who is paying for a permit must be certain that there bike is secure. We might want to have security cameras.

Parking

We discussed efforts to encourage less driving through parking incentives. Pete suggested having a passenger-car-free campus zone by placing parking outside of certain zones of campus. This idea was well received by the group and generally liked. However, we discussed challenges to any parking changes. We discussed specific proposals to adjust parking prices, shown here:

-          Try to price people out of parking and mitigate this by reducing the price at other locations

-          Allow flexible payment in percentage of salary

-          Have and “auction” in which whoever pays the largest percent of their salary gets the closest location.

-          Remove or lift parking cap so that wealthier parkers pay more and thus provide more revenue

-          Have a private company raise rates on parking

Then, we discussed challenges to these proposals:

-          Parking is important to unions – any changes may result in strikes or political conflict

-          The sentiment of Parking and Campus master plan does not necessarily agree with people parking farther away – an objective that would be achieved through a passenger-car-free zone

-          Hiring private company likely not a good idea – their primary motivation is profit

-          City of Champaign changed parking ordinances so that spaces at churches, fraternities, etc, decrease

Our next meeting is TBD.

Updates and discussion of greywater meter, greywater design standards, cooling tower cycles of concentration, water use dashboard, and student outreach. 

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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