Geoff Howland. Value Development Manager

Transcription

1 Geoff Howland Value Development Manager Chevron Energy Solutions MacArthur Plaza 5525 N. MacArthur Blvd Suite 290 Irving, TX Tel Cel Fax ghowland@chevron.com March 27, 2009 Steve Polasek Assistant City Manager City of Keller 1100 Bear Creek Pkwy Keller, TX Dear Mr. Polasek, The Chevron team would like to thank you and the City of Keller for the opportunity to conduct a citywide Feasibility Energy Analysis. We visited several facilities and interviewed key associates over the past several months. Our goal was to identify opportunities to reduce energy consumption, reduce total operating expenses and possibly enhance water revenues within the City. Our report is attached. We have concluded that there are no areas for improvement beyond a few relatively small energy conservation opportunities. We have made a few recommendations that we feel the City can pursue on its own and have provided information to assist in developing next steps. Also, we had planned to review water meter data collection, data handling and percent of unaccounted for water as well; but found that the City s systems were in fact as good as or better than most in the state. As we discussed, there may be a potential for solar or geothermal energy in future construction projects. We found all City employees to be very helpful during on-site facility inspections and the review of maintenance procedures. The City of Keller is to be commended for its focus on operational excellence and continuous improvement. It is clear that there is a strong sense of ownership in everyone we met. If we can be of any assistance in the future please contact me. Best regards, Geoff Howland Value Development Manager C:\Documents and Settings\hgoe\Desktop\My Desktop\02 Cities\City of Keller\FEA.Cover.Letter.doc

2 Feasibility Energy Analysis City of Keller, Texas March 2009 Chevron Energy Solutions Company A Division of Chevron U.S.A. Inc North MacArthur Boulevard, #290 Irving, TX Tel Fax

3 Feasibility Energy Analysis City of Keller, Texas Prepared by Chevron Energy Solutions Company A Division of Chevron U.S.A. Inc. March 2009 DWCES 31953

4 BACKGROUND The City of Keller facilities include Keller Town Hall, the Municipal Service Center, the Keller Pointe, the Keller Police Department, the Senior Center, the Library, Fire Departments 2&3, and Fire Department 4. Chevron Energy Solutions conducted site surveys on January 30 and March 3, 2008 with the assistance of Earl Lewis and Tony Farina. Both staff members were very helpful describing systems, identifying the building needs, and showing the equipment. During the site visits the following energy conservation opportunities were evaluated: Lighting Systems Heating, Ventilation, and Air Conditioning (HVAC) Equipment Building Controls Building Envelope Water Conservation Each of these topics is discussed in the sections that follow. Based on 2007 utility data total city facility expenses were about $592k per year for electricity, about $68k per year for natural gas, and $46k for water and sewer. TOWN HALL- 53,544 s.f. This facility is about 7 years old and is in very good condition. There are large expanses of glass walls with double pane reflective glass. The lighting is primarily electronic ballasts with T5 or T8 lamps. The water using devices are up to current standards. The HVAC system utilizes four Rooftop units (RTUs), one split system DX unit, and two Liebert units for computer rooms. RTU #1&2 are 40 ton Trane units each with six compressors. The units deliver air to many Variable Air Volume (VAV) Boxes in the spaces which can provide electric heat. The Intellipack Trane Rooftop units are very high quality with variable speed fans and six stages of cooling capacity. RTUs 3&4 are 20 ton Trane units in very good condition. The three ton split system and 2 ton Liebert are also in good condition. The exhaust fans for the restrooms run 24/7 The HVAC systems are controlled by a Trane Summit Building Automation System which appears to provide adequate capabilities to meet the needs of this facility. OPPORTUNITIES at TOWN HALL 1

5 The main savings opportunities associated with this facility include controls on the exhaust fans and additional barriers near the main entrance to limit the infiltration of air when the doors are open. The exhaust controls may be best implemented with a strategy that monitors the CO 2 and building static pressure levels in the facility. We recommend the city work with Trane to make sure the restroom exhaust fans are turned off after hours. Additional savings may be achieved by implementing CO 2 monitoring for air quality to optimize the intake of outside air. The changes at the entrance of the facility would be highly visible so Chevron recommends working with the designer of the facility to come up with an entrance solution that complements other building features nearby. FIRE DEPARTMENT 2 & 3-5,520 s.f. each During the survey we did not actually enter the facility because the firemen were out on a call. A cursory view from the outside indicated the following information. The facility was built in 1994 and is therefore up to current standards on water using devices. The outside is brick and stucco with double pane glass windows. The truck bay is heated with seven gas infrared heaters. It is assumed the lighting is T8 with electronic ballasts. The living and work areas are conditioned with two DX split systems, one at 7.5 tons and one at 5 tons. The indoor furnaces use gas. It is assumed the equipment is controlled with standard thermostats which is adequate for facilities that are occupied 24/7. OPPORTUNITIES AT FIRESTATION 2&3 At this time no energy conserving retrofits were identified for these sites. The HVAC equipment still has a few years of service life. 2

6 SENIOR CENTER- 3,240 s.f. The facility is 18 years old and has double-pane glass windows and a brick exterior. The indoor lighting consists of approximately 30 fixtures which use T12 lamps and electromagnetic ballasts. Several exit lights are incandescent. The plumbing fixtures are up to current water usage standards. The facility is conditioned with two 5 ton split systems with gas heat which are in fair condition. These units are controlled with standard thermostats. OPPORTUNITIES AT SENIOR ACTIVITIES CENTER Chevron recommends the lighting be retrofitted with new T8 lamps and electronic ballasts. Incandescent exit lights need to be replaced with LED exit lights. The two thermostats should be replaced with programmable thermostats to minimize runtime when the building is unoccupied. If the city does these installations in-house there will be a payback of less than 3 years on the lighting, and two years on the programmable thermostats. LIBRARY- 22,000 s.f. with proposed expansion 3

7 The Library is 18 years old and is scheduled for a remodel and expansion soon. It has double-pane glass windows and a brick exterior. The indoor lighting is primarily T12 lamps with electromagnetic ballasts. The facility is conditioned by four gas/electric rooftop units which are controlled by standard thermostats. OPPORTUNITIES AT THE LIBRARY The energy conservation opportunities at this facility will be captured when the facility is renovated and expanded. The new equipment to be installed should use ozone-friendly refrigerant such as R410. For many years new RTUS used primarily R22. R22 is to be phased out and after January 1, 2010 no production or importing of new equipment using this refrigerant will be allowed. MUNICIPAL SERVICE CENTER- 29,938 s.f. This facility is about 5 years old and consists of a brick exterior with double pane glass windows. Since the facility is so new the water using devices are up to current standards. The lighting is primarily T8 with electronic ballast. Most of the office areas are conditioned from the main air handler AHU 1 which is a 30 ton two stage DX system which delivers air to VAV boxes. Hot water heating coils in the VAV boxes are connected to the HW boilers for building heat. A small 2 ton split system with electric heat serves the sign shop. 4

8 The domestic hot water is provided by two 100 gallon gas HW heaters. The building heat is provided by two 150MBH high efficiency condensing HW boilers. The larger HVAC equipment is on a building automation system, and the smaller split system DX units are on programmable thermostats. OPPORTUNITIES AT MUNICIPAL SERVICE CENTER No energy conservation opportunities were identified at this site. POLICE DEPARTMENT- 26,676 S.F. The Keller Police Department was built in two phases, with the front newer addition completed in Older section with the jail was built in The lighting is primarily T8 with electronic ballasts. There are approximately 25 light fixtures in the jail which are T12 with electromagnetic ballasts. Several exit lights are incandescent. At least one toilet in the jail area was found to be above the 1.6 GPF current usage standard for efficiency. The HVAC system serving the newer front area is a Trane Rooftop unit similar to the Intellipack unit at the Town Hall. This unit provides air to VAV boxes with electric heat in the spaces. This unit is controlled by the Trane Summit Building Automation System. The original building is served by nine split system DX units ranging from three to five tons each with electric heat. These units are also connected to the Trane control system. OPPORTUNITIES AT THE POLICE STATION Chevron recommends retrofits to the light fixtures in the jail area to T8 with electromagnetic ballast. Incandescent exit lights should be replaced with LED exit lights. 5

9 Some of the older toilets could be replaced with new 1.6 GPF units. If these retrofits are done in-house they should provide a payback in the 3-5 year range. KELLER POINTE 59,276 S.F. The Keller Pointe facility is five years old. The facility is open daily from 5:00AM to 10:00 PM. The windows are double pane glass with window film on most windows. The facility uses highly efficient lighting systems and plumbing fixtures. The HVAC system at this facility utilizes three Trane rooftop (RTUs 3, 4, &5) units ranging from tons each with hot water heating coils and economizers. The economizers are used during mild weather when the outside air is below 50% relative humidity. Three smaller split system DX units serve smaller dedicated areas such as concession, birthday party, and lifeguard offices. The Trane rooftop units are connected to Variable-Air-Volume (VAV) boxes or Fan-powered boxes which serve individual rooms. The pool area is served by a dedicated Dryothon DECTRON unit which is designed to keep the pool area at 50% relative humidity 85 degrees F. This pool HVAC system has two dedicated Raypak hot water boilers which heat the pool and serve the DECTRON unit on the roof. The mechanical room on the ground level has two PVI 250 gallon domestic hot water heaters and two 880 kbtu output high efficiency Lockinvar hot water boilers to heat the building. The HVAC systems are connected to the Trane Summit Building Automation System and equipment operates on schedules. OPPORTUNITIES AT KELLER POINTE The facility has long hours of operation and there are space temperature constraints for different areas. Three energy conservation opportunities were identified. Around the perimeter of the pool area there are twenty-six (26) 1000 watt metal halide indirect light fixtures and in the exercise room there are ten (10) similar fixtures. These metal halide lamps are very intense but they loose a large percentage of their available illumination because they are directed towards the ceilings. More usable light will be provided to these areas after these fixtures are replaced with four lamp T5 or T8 fixtures. The mounting rods in the pool area may be reused to keep the costs down. The lighting retrofit alone will save about 30 kw demand and about 15,000 kwh per month which is about 6% of the kwh used at this facility. The savings will be around $15k/year and the simple payback will be less than three years. The second energy conservation measure includes new window film on the west wall of the pool area. There are premium grade films available that reduce the solar heat gain by about 55% yet do not appreciable impact the visible light entering the window. The majority of the facility already has high quality commercial grade window film which was installed in a very professional manner. The cost for the window film will be around $5k and the simple payback for new window film should be about 3 years. The third energy conservation measure includes indoor air quality monitoring with CO 2 sensors. The volumes of outside air delivered to the areas can be matched to the 6

10 occupancy to reduce the amount of excess outside air. The conditioning of outside air is energy intensive and therefore expensive. Since the existing levels of excess outside air are unknown the savings for this retrofit cannot be evaluated at this time. There does not appear to be adequate space on the roof to install a solar water heating system for the pool. ENERGY ANALYSIS The utility bills for 2007 were used to determine the following annual kwh/s.f. metrics: Town Hall- MSC kwh/s.f. 12 kwh/s.f. Police Courts- 27 kwh/s.f. Library- 15 kwh/s.f. Senior Center 17 kwh/s.f. Keller Pointe 49.5 kwh/s.f. Over half the annual electric bill for the entire city is associated with the Keller Pointe facility. Since this facility is relatively new and is already connected to the Trane automation system, there does not appear to be simple ways to reduce electricity usage other than described earlier. The kwh usage at the other facilities is very reasonable compared to similar facilities in this region. 7