Energy Conservation Measures

The Chilled Water Plant at the Veterinarian Center provides chilled water for the Basic Sciences Building, Large Animal Clinic, Small Animal Clinic and Surgical Obstetrics Lab. It is equipped with four centrifugal chillers, one absorption chiller, and three cooling towers located on the roof of the chiller plant. The control system maintains a constant condenser (cooling tower) water temperature of 85ºF. By lowering the condenser water set point temperature, the chillers will operate at a cooler condenser water temperature which greatly improves their efficiency. Chiller efficiencies improve with every degree the condenser water temperature drops. This percentage can be as much as 1-2% depending on which chiller is on.

Assuming a 1% efficiency improvement per degree of condenser water temperature and a 5-degree temperature differential, this will result in a 5% overall savings on the chiller efficiency per year.

ESG has converted the chilled water plant from a constant volume to a variable flow to maintain a constant differential pressure that will allow the chilled water pumping distribution pressure to dynamically increase/decrease based upon system requirements, and not on a fixed differential pressure set point. As pressure requirements are reduced, pump speed and flow will also typically be reduced, resulting in pumping energy savings. 

The flat roof of the Small Animal Clinic, Surgery & Obstetrics Lab, Central Plant and the lower flat roofs of the Large Animal Clinic are coal tar pitch built-up roof systems that are between 30 and 40 years old. Over the years, the roofs had been patched in many areas to repair active leaks. Due to the age of the roofs, insulation is minimal.

As part of the Vet Med Energy Efficiency ESCO project with ESG, the F&S team will replace this existing roofing with a new 60-Mill EPDM Roof System. Upon completion, the University will be issued a 20-year manufacturer's warranty. A key benefit of this new roof is maximized insulation which effectively enhances energy efficiency throughout the Vet Med buildings, leading to lower energy and operational costs and enhanced work environments.

EPDM, or "rubber roof", is the most common form of membrane roofing available. It is a single-ply membrane comprised of rubber compounds and other chemicals. Rubber roofing comes in different mill thicknesses (i.e., 45 mill, 45 mill reinforced, 60 mill [the most common], 60 mill reinforced, and 90 mill) and widths.

EPDM has been in use on roofs in the USA since the 1960's and is one of the most common types of low-slope roofing materials. This is because it is relatively inexpensive, simple to install, and fairly clean to work with when compared to conventional built-up roofs. There aren't the odors and fumes that accompany built-up roofs which appeals to many property owners and managers.

A comprehensive energy audit of the Vet Med Complex buildings identified that some of the energy in the University's steam distribution system is wasted through radiant thermal energy loss due to un-insulated and deteriorating sections of steam and condensate piping. The F&S and ESG team will insulate these sections of piping in order to minimize thermal energy loss and maximize energy efficiency.

New fiberglass pipe insulation will be installed on the steam, condensate piping and steam valves. In addition, an aluminum jacket will be installed on the lines between air handling units to protect the insulation. The insulation thickness will be according to the University's specifications for steam and condensate piping.

Fiberglass pipe insulation is made from high quality fiberglass fibers bonded together with a thermosetting resin. It is a lightweight, one-piece, cylindrical product that offers excellent resistance to heat loss or gain, which saves energy and lowers operating costs. 

Operating the Basic Science Building (BSB) effectively requires proper ventilation and large amounts of outside air brought in for lab areas. The fume hood system allows faculty and students to conduct experiments by exhausting fumes, vapors and dusts.

The Vet Med ESCO is working to achieve a balance between the need for fume hood functionality, throughout BSB, and improved technology allowing this system to become more energy efficient by converting to variable air volume (VAV).

Fume hoods are historically large energy users because when left open conditioned air flows out of buildings. The updated systems installed by the Vet Med ESCO, 62 retrofitted fume hoods, will reduce energy consumption and provide future cost savings by minimizing the loss of conditioned air. Also, approximately 25 existing VAV boxes were relocated to allow for room control actuators and further optimized performance. Twelve new VAV boxes will be added to the system to provide increased energy savings.

The Vet Med ESCO will provide additional upgrades to the fume hood system. Currently, most of the fume hoods are individually exhausted with a dedicated fan and sometimes one fan works with multiple fume hoods. To improve performance, these exhaust fans will be replaced with a centralized high plume exhaust fan system that provides greater exhaust capacity.

As with all installations under the Vet Med energy efficiency project, work will be conducted in a manner that ensures minimal inconvenience to students, faculty and staff. 

All buildings require outside or “fresh air” in order to maintain an acceptable indoor air quality. Engineering standards have differing amounts of outside air requirements depending on the space utilization and occupancy. Traditionally, spaces are designed and operated to ensure that the ventilation rates are met at all times regardless of whether the spaces are occupied. Existing technologies allow for ventilation rates to be adjusted based on occupancy and/or air quality. This ensures acceptable air quality during occupied periods while maximizing energy efficiency, especially at times of low or no occupancy.

The concept of varying ventilation based on occupancy is called demand control ventilation. This strategy was implemented as part of the Vet Med ESCO project. Many areas with varying occupancies are operating with demand control ventilation in the BSB, LAC, SAC and CSLC for human and animal occupants. Carbon dioxide and/or occupancy sensors are used in offices and lecture centers to vary ventilation rates throughout the campus. Large animal wards in the LAC have air quality sensors monitoring multiple parameters to vary the ventilation rates. These demand control ventilation improvements are expected to save approximately $50,000 annually in energy costs while ensuring acceptable air quality is met at all times.

The Vet Med complex is heated, cooled and ventilated with air handling units located throughout the buildings. These units represent a significant portion of the total energy utilized in the complex. Most of the units in the Large and Small Animal Clinics are original to the construction of the building and have exceeded their useful lives. Because of their age, the units required excessive maintenance and were not as efficient as newer units.

New units were installed as part of the Vet Med ESCO project to reduce maintenance and energy costs. The new units are installed in centralized locations and are sized to serve multiple areas, which has reduced the total number of air handling units needed from 10 to 4. The new units utilize enthalpy wheel heat recovery. This allows the waste heat to be recovered by as much as 75%, thereby significantly reducing the energy costs.

Additional energy efficient technologies were utilized in the new units including variable frequency drives, pressure independent control valves, and direct digital controls. All units were installed while the facility was fully functional in a manner that minimized inconvenience to students, faculty, staff and patients.

Most heating and cooling in buildings is done by mixing air to maintain a predetermined temperature. This requires large amounts of air to be mixed at high velocities. Although effective, this type of ventilation is energy intensive. An alternate mode of ventilation called “displacement ventilation” allows for energy efficient temperature control. This concept has been successfully utilized in Europe for decades.

The principle of displacement ventilation involves air supply and distribution in a room in an upward motion. The air flow is supplied at the bottom of a room at lower velocity and at a temperature just slightly below the room temperature. As the air rises it cools the occupant and the room. Because lower volumes of air are required at a higher temperature to maintain the same temperature as a traditional system, lower energy consumption is achieved.

The concept of displacement ventilation was implemented in the Vet Med ESCO project for the animal wards in the Large Animal Clinic (LAC). The displacement ventilation system is expected to save approximately $46,000 annually in energy costs and will maintain quality comfort for building occupants. 

The Basic Sciences Building (BSB) was originally designed as a variable air volume (VAV) system with hot water reheat. However, due to the inability to maintain comfort, the VAV system was abandoned. The system was converted to a constant volume reheat system.

This building is a large consumer of energy because of the need to bring in large amounts of outside air to satisfy the exhaust requirements and code-required ventilation rates. The ESG team implemented energy efficiency improvements that will maximize the operational efficiencies of these systems to operate with reduced ventilation rates during unoccupied hours.

• ESG converted nearly 500 boxes to a variable air volume (VAV) system

• 62 new VAV boxes were installed

• Hot water reheat valves were replaced in all supply air boxes

• 25 VAVs were rotated in order to attach the new controls

• New direct digital control thermostats were installed for each VAV box

• Web-based building automation system was created to monitor and control the boxes

Water Conservation

Steam Trap Program

Coil Cleaning

Variable Frequency Drive (VFDS) and Motor Replacements

Refrigeration Equipment Heat Recovery

Doors and Weather Stripping

Chilled Water Variable Flow