DESIGN ASSOCIATES INC MECH/ELEC DESIGN & CONSULTING 422 Highland Ave, Cheshire, CT. 06410 (203) 271-3787, fax (203) 271-2886 Proposed Mechanical, Plumbing, and Electrical Systems For the LEDYARD POLICE DEPARTMENT LEDYARD, CT February 3, 2014 A site visit was conducted as well as a review of the proposed two story design by JHA to evaluate proposed MEP systems for the project. Additionally preliminary load calculations for heating/air conditioning and electrical loads were done to define design parameters. PRESENT CONDITIONS and ISSUES Plumbing Systems 1. Review of adequate domestic water capacity for the building needs to be determined. It was reported that the flow may be lower than normal. This may require the use of pressurized storage tanks needing to be used for the project as well as if we can use flush valves or have to use flush tank type fixtures. 2. Low flow use fixtures are to be used in the design. Fire Protection 1. No fire protection system is proposed for the facility and is not required by code per JHA s review. 2. The prisoner cells may have a domestic supplied limited sprinkler heads if sufficient pressure and flow is found from the water main. Electrical Site 1. The present site has limited site lighting pole fixtures towards the rear combined future police facility and the town hall buildings. 2. There is a primary overhead electric service with multi site installed poles on the property that need to be relocated to allow rework of the site entry driveways and parking. This pole line will have to be relocated or redesigned underground with the cooperation of CL&P Company. 3. The existing service to the town hall building is an overhead 400 amp, 1-phase with service head conduit that will have to be re-worked from any new primary system.
2 4. We understand that the existing two rear buildings will be removed and they do not need new electric service. 5. We could not determine how the Town Hall Annex building was served but It appeared to come from the last pole next to the tower. This will have to be refed. 6. The existing easement will need to be redefined for relocation of the service to anything else that is serves. PROPOSED NEW SYSTEMS Plumbing Systems 1. Provide new low flow Green Design plumbing fixtures for the proposed new facilities. 2. Provide new low flow Cell fixtures for the prisoner areas. 3. Propose new non freeze wall hydrants for the perimeter walls. 4. Propose a new high efficiency condensing hot water heating system for the plumbing fixtures that shall be LP gas fired. This system shall be part of the heating plant and consist of a heating circuit off the boilers to an indirect hot water storage heater with thermostatic mixing valve and recirc pump. 5. A proposed new LP gas service will be designed to be underground from new underground LP gas storage tanks in the rear of the facility. 6. A new 2 minimum domestic water service shall be routed into the building with a new water meter assembly. 7. Sally Port drainage shall be taken to an outdoor oil separator and underground holding tank. 8. Some hose bibs should be provided in the prisoner cell areas along with floor drains in the local corridors to allow wash down of that area. Fire Protection 1. Not required per code. Heating, Ventilation and Air Conditioning. There are options for the new systems that range from high efficiency to mid efficiency that also range in higher first costs as the efficiency increases. The following outlines these system designs: Option A (very high cost, highest efficiency) 1. A geothermal unitary heat pump system for heating and cooling is proposed using unitary geotechnical well based Heat Pump Air Handlers for (simotaneous heating and cooling of the entire facility. 2. This system will require a field of geotechnical ground loop wells. (It is estimated at this time that it would require approximately (12) 400 deep wells to support the anticipated load for the building of 25 tons of cooling. The unitary units shall have free cooling outside air economizers and have condenser heat exchangers that marry to a geothermal ground loop piping and pumping system.
3 3. The efficiency of these units range depending on tonnage sizing of 15.7 EER to 17.3 EER at full loading. The heating efficiency has a range of 3.4 to 3.6 COP. 4. The system should have a backup boiler plant (that will also serve the domestic hot water heating) and connections for a future above ground closed loop cooling tower should the ground loop system fail to deliver the full extent of energy transfer required for the system. The boiler system is proposed to be very high efficient Condensing Hot Water Boilers that shall have an efficiency of 93 to 95% using LP gas and a 1000 gallon underground fuel storage tank. 5. The condenser loop pumps shall be very high efficient type using ECM technology. 6. The unitary heat pump units would consist of approx 5 to 6 air handlers that would be designed to serve different exposures and spaces in the facility. 7. Local VAV control dampers could be used on these systems to allow individual room controls with the use of bypass air control. 8. The Sally Port bays would be designed with heating and ventilating equipment only that is served by the boiler plant. No AC is proposed. 9. A building wide Energy Management System is proposed to control all of the systems for total monitoring and energy conservation programming. Option B ( mid range costs, very good high efficiency) 1. In lieu of the geothermal unitary heat pump system, it is proposed that this option use the same system as noted for Option A above but without the ground loop wells and piping system. 2. This system anticipated load for the building is 25 tons of cooling. The unitary units shall have free cooling outside air economizers and have condenser heat exchangers that marry to a low temperature condenser looped piping system in the building that is served by an outdoor closed circuit cooling tower, boiler plant and primary/secondary pumps system. 3. The efficiency of these units range depending on tonnage sizing is STILL VERY EFFICIENT providing 14.3 EER to 15.7 EER at full loading. The heating efficiency has a VERY HIGH range of 4.6 to 4.8 COP. Also note that units are available with two stage heating and cooling controls for part loading which increase the above efficiencies to up to 17.7 EER and 5.3 COP 4. The system shall have two small wall mounted very high efficiency boilers (that will also serve the domestic hot water heating). The boiler system is proposed to be very high efficient Condensing Hot Water Boilers that shall have an efficiency of 93 to 95% using LP gas and two approx 1000 gallon underground fuel storage tanks. 5. The heating/condenser pumps shall be very high efficient type using ECM technology (basically twice as efficient as standard pumps). And designed with full backup pumps.
4 6. The unitary heat pump units would consist of approx 5 to 6 air handlers that would be designed to serve different exposures and spaces in the facility. Dedicated systems are proposed for the Dispatch Center, as well as a proposed ductless split high efficiency heat pump for the Communications Equipment Room. The prisoner processing area and cells are proposed with a dedicated system that has no return air but will be provided with an ERU as noted below. 7. Local VAV control dampers could be used on these systems to allow individual room controls with the use of bypass air control. 8. The Sally Port bays would be designed with heating and ventilating equipment only that is served by the boiler plant. No AC is proposed. 9. The Prisoner Processing Area system shall utilize an energy recovery heat exchanger ERU to capture the large exhaust air and reclaim it to the new fresh air to the unit. These ERU s have recovery ratings of up to 75% efficiency. 10. A building wide Energy Management System is proposed to control all of the systems for total monitoring and energy conservation programming. Option C (lowest first costs, and fair to good efficiency) 1. Propose conventional unitary split system heating and air conditioning units that shall have refrigerant based DX cooling coils and remote outdoor high efficiency condensing units. These units shall have cooling efficiency of between 14 SEER and 17 SEER. (approx 12 to 13 EER). 2. We propose the same number of unitary air handlers as the systems noted above that shall have the DX cooling and Hot water heating coils, economizer dampers. 3. This system can also have the VAV options. 4. An EMS system shall be provided for full efficiency operation and monitoring of the systems. (Due to the complexity of the HVAC equipment for this project, it is unlikely that conventional stand alone local thermostats can be used. (The Prisoner Processing and Sally Port areas require special controls for their proper operations.) 5. The boiler plant pumps shall be very high efficient type using ECM technology. 6. The system uses the same boiler heating plant design as noted above that also serves the domestic hot water heating system. 7. Dedicated systems are proposed for the Dispatch Center, as well as a proposed ductless split high efficiency heat pump for the Communications Equipment Room. The prisoner processing area and cells are proposed with a dedicated system that has no return air but will be provided with a ERU as noted above.
5 Electrical Lighting 1. New interior electrical lighting shall be energy efficient fluorescent and a mix of some LED lighting where feasible. All exit lighting shall be LED. 2. Exterior lighting for the parking and driveways could be either LED or HID high efficient type using metal halide lamps. The parking lot shall be lighted to a minimum of a range of.35 FC to 1 FC. 3. Lighting in the prisoner cells shall be high security fluorescent or LED. Electrical power and distribution 1. A new 800 amp, 3-phase, 120/208 volts, 60 Hz, service with new pad mounted transformer shall be provided. Power and lighting distribution panels will be provided. 2. It may be possible that one ground mounted utility company transformer can be used to supply underground power to each building. Exception is that the existing town hall has 120 /240 volt 1-phase service and also has solar photovataic solar collector system that may not be able to be converted to 208 volts. It is proposed that a single pad mounted transformer be used to supply both buildings but the town hall will have to be converted if possible with any 240 volt equipment to 208 volts or have buck/boost transformers added to the equipment where found. The rear building would be served the same as the town hall and also have buck/boost transformers added to the equipment. Emergency generator system 1. Provide a new self contained emergency generator that has its own built in diesel fuel supply and place it out back away from the building. 2. Provide it with a new ATS that is sized to transfer the entire building s electrical load. Estimated size of about 150 KW to 200 KW. Communications Systems 1. Provide a new Addressable Fire Alarm System for the facility with a remote anunciator located in the Dispatch area. 2. Provide CAT 6 Telephone wiring and data wiring infrastructure for the facility. 3. Provide a central speaker intercom system for the corridors and physical training areas or where phones are not located that shall be interconnected with the telephone system. 4. Provide new Cable TV and Telephone underground conduits to the street pole and new demarks.
6 5. Provide internal prisoner area intercom system that shall be monitored and recorded by the Dispatch area. 6. Provide a CCTV internal and external camera system with digital recording. Lightning Protection System (optional) 1. Provide a fully engineered lightning protection system for the building and roof equipment that is fully grounded and bonded to the building steel and ground rods. Cost Comparison Life Cycle Cost payback of the proposed HVAC Systems: Assuming that all of the systems use the same amount of ductwork distribution system, VAV dampers and EMS system controls, the cost comparison looked at the general cost differences of each system fully installed. Actual payback is unknown and depends on a lot of factors such as building usage, temperature settings, control functions and IF the ground loop system can produce the required capacity based on using the estimated 12 wells. Note: The values shown are not the cost of the entire building mechanical systems. Also Note: The actual yearly operating costs noted are only guestimates. These values are produced by the LCCA software program which we have no control over. Other factors include changes in fuel costs and actual usage of the building as well as using a reliable energy management system for its controls. Option A - Geothermal unitary heat pump system for heating and cooling is proposed using unitary geotechnical well based Heat Pump Air Handlers with backup heating plant and future valved off connections for backup cooling tower. (The well costs are based on a previous project actual installed cost with inflation added). Cost of geotechnical wells $296,000 Cost of geotechnical piping $ 62,000 Heat Pump Units, piping, ductwork, etc $231,000 Backup boiler system $ 22,000 EMS controls $ 70,000 Total $681,000 Estimated payback as compared to Option C = 15 to 20 years. (if Clean Energy Funds are still available, It may be as low as 7 to 10 years.) Estimated yearly operating costs = $10,000 based on LCCA program.
7 Option B - Unitary heat pump system with closed circuit cooling tower and boiler plant. Cost of Closed Circuit Cooling Tower $ 48,000 Heat Pump Units, piping, ductwork, etc $231,000 Boiler system $ 24,000 EMS controls $ 70,000 Total $373,000 Estimated payback as compared to Option C = 4 to 5.5 years. (CL&P incentives are available as well) Estimated yearly operating costs = $13,000 based on LCCA program. Option C - Conventional split system air handlers with DX cooling with remote outdoor condensing units and hot water heating boiler plant. Split System AC units $209,000 Boiler System $ 24,000 EMS controls $ 70,000 Total $303,000 (CL&P incentives are available for this equipment) Estimated yearly operating costs $32,000 based on LCCA program. END OF REPORT