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Existing hydronic systems in the Maintenance Building are in extremely poor condition. Repair is required to remedy building heating and cooling issues.

System piping, valves, and trim are all damaged by system corrosion and resulting debris. With the exception of piping installed during the 2000 and 2001 projects in the Training rooms and Electrical shop, heating and chilled water piping 2-inches in diameter and smaller will be replaced. Isolation valves, pressure relief valves, strainers, automatic air vents, gauges, and other trim outside of the 2000 and 2001 projects will also be replaced. As discussed in the central plant heating and chilled water system descriptions, an initial chemical flush will be performed to remove corrosion and sediment from the distribution piping intended to remain, and water treatment will be added to the hydronic distribution systems.

Heating and cooling coils in existing air handling units that will not be replaced including AHU-1, AHU-2, AHU-3, and AHU-1B will be flushed. Non-functional cabinet unit heaters that failed as a result of corrosion will be removed where not needed to meet current heating requirements. Recommended changes to the central plant heating and chilled water distribution systems eliminate the need for building pumps. Accordingly, all building pumps will be removed except where required for coil freeze protection. Pumps removed will include Maintenance Building HWBP-1, CWBP-1, P-1A, and P-2B.

A summary of recommended system repair, replacement, and upgrades includes the following:  Demolish pumps HWBP-1, CWBP-1, P-1A, and P-2B.

 Demolish cabinet unit heaters CUH-6 and CUH-7.

 Replace all heating and chilled water piping 2-inches in diameter and smaller (except Training rooms and Electrical shop).

 Replace all hydronic isolation valves, strainers, pressure relief valves, automatic air vents, gauges, and other trim except in the Training rooms and Electrical shop areas.  Provide a system flush and water treatment of the heating and chilled water systems,

including:

o Initial system flush including installation of a temporary bypass to isolate the Maintenance Building.

o Installation of a basket strainer to catch debris.

o Circulation of a chemical mixture designed to scour corrosion products from the heating and chilled water piping.

 Flush cooling and heating coils in air handling equipment not recommended for replacement. The equipment includes AHU-1, AHU-2, AHU-3, and AHU-1B. Provide testing, adjusting, and balancing for Maintenance Building chilled and heating water coils and pumps.

The approximate construction cost for HVAC work in this category would be $60,600. 3.1.2.2 Central Air Handling Systems

The existing main air handler has significantly exceeded its service life. Given the initial quality, the service history, and the age of the unit, refurbishment is not likely to meet the county long term system reliability goals, and replacement is recommended.

Since most building piping and many of the other system components have also exceeded their service life, conversion to a different overall system type is recommended. Presently, the system is a dual-duct, constant volume configuration. The air handling unit delivers heated air and cooled air to terminal units with the overall delivered air flow remaining constant. At the terminal units, heated air is combined with cooled air to provide a delivery temperature that meets space demand. The control systems are optimized to keep the difference between the heated air temperature and the cooled air temperature as low as possible. However, the continued mixing of heated air and cooled air is very energy intensive, and this system approach is no longer used.

As an alternative, conversion to a single-duct, variable-air-volume system with reheat is recommended. Such systems are the norm for current office design, and the approach will provide significant energy savings. Using this approach, the central unit only provides cooled air to terminal units. At the unit, the amount of air is regulated to meet the cooling demand. Regulating airflow saves cooling energy and fan power requirements. When heating is required, a reduced amount of air is delivered to the terminal unit where it is reheated as needed to meet space demand. Some mixing of heated and cooled air still occurs, but the amount of mixing and the fan motor energy consumption will be much less.

The conversion will require replacing the existing central fan with a unit equipped with filter, warm-up heating coil, and cooling coil. The fan will be equipped with an inverter rated motor and variable frequency drive. Existing booster fans will be refurbished and equipped with variable frequency drives to allow return air rates to match changes in supply.

The existing ductwork will be reused. With the new approach, both the existing hot duct and cold duct will distribute air to the building. Since both ducts are currently sized to deliver 100% of the system flow, use of both ducts to deliver cooled air results in lower ductwork pressure loss and a further reduction in fan energy use.

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Conditions Survey Section 3-8

All existing dual-duct terminal units will be replaced with single duct terminal units equipped with reheat coils. For large spaces with high heating loads, terminal units will include fans and a return connection to the space served. The fan powered terminal units allow delivery of a constant amount of air to a space when the unit is in heating, which will reduce stratification effects in high ceiling areas.

Installation of terminal units with reheat coils will require extending the existing heating water piping network to serve new coils. All new coil trim will be provided.

The existing system received a fixed amount of outside air that was preheated using central toilet exhaust. The preheat exchanger was removed apparently because the unit plugged. A similar exchanger will be re-installed with appropriate filters to prevent future failure. However, the amount of air delivered by the preheat system was based on the code at the time and does not meet current ventilation requirements. Additional outside air capacity is needed. In addition, the system was not configured to allow cooling using additional outside air (economizer cooling). It seems likely that the designer concluded that moderate cooling requirements that can typically be met with outside air can also be met by using direct well cooling in the original central plant. This will no longer be entirely true. Conversion of the chilled water system from an open loop to a closed loop will reduce the amount of “free cooling” that can be provided by well water only, and addition of 100% outside air capability is recommended. Associated work will include addition of an outside air louver connected to the unit inlet, a relief opening from the mechanical room, and associated controls to modulate the amount of outside air provided. A benefit to adding outside air capability is that additional ventilation air can be provided as required.

Direct digital control will be provided for all central air handling systems. Recommended changes and upgrades include:

 Demolish existing air handling unit HCU-1.

 Demolish the existing exterior door to mechanical room 427.

 Cut an opening in the concrete exterior wall of room 427 for a new outside air louver and expand the existing door opening from 6'-4" wide to 7'-4" wide.

 Provide a new exterior 7'-0" wide by 7'-0" high double door for mechanical room 427.  Provide a new air handling unit with the following features:

o Economizer damper section

o Filter section with replaceable MERV 11 filter panels o Heating water preheat coil

o Chilled water cooling coil

o Supply fan with variable frequency drive and inverter rated motor o Discharge plenum

 Re-connect the existing hot and cold deck supply ducts to the new AHU discharge plenum. Both ducts will be used for cooled air supply.

 Refurbish the existing booster fans:

o Replace drive belts, sheaves, and bearings. o Clean and balance fan wheels.

o Remove rust and repaint areas with minor corrosion damage.

o Replace the motors on booster fans BF-1, BF-2, and BF-3 with premium efficiency inverter-duty rated motors.

o Provide new variable frequency drives for booster fans BF-1, BF-2, and BF-3. o Replace the existing air-to-air heat exchanger and rooftop exhaust fan REF-1

associated with BF-4.

 Demolish existing terminal units and cap return ductwork connections to the existing fan- powered terminal units.

 Provide VAV terminal units with heating water reheat to replace existing terminal units in core zones or zones with moderate exterior exposure or heating load.

 Provide fan-powered VAV terminal units with heating water reheat to replace existing terminal units in high ceiling areas and zones with large exterior exposure or heating load.

 Modify existing low pressure ductwork downstream of terminal units to better match current function in rooms 438 and 455.

 Remove pneumatic controls throughout, and provide new direct digital controls for all central fan system components.

 Provide testing, adjusting, and balancing (TAB) services for HCU-1, BF-1, BF-2, BF-3, BF-4, and all Terminal Units associated with the new air handling system.

The approximate construction cost for HVAC work in this category would be $400,200.

3.1.2.3 Secondary Air Handling Systems

Recommendations for replacement or refurbishment of Maintenance Building secondary systems are discussed on a system-by-system basis below.

SINGLE ZONE AIR HANDLERS

Air handling units AHU-1, AHU-2, AHU-3, and AHU-1B were installed in 2000 and 2001 and are in good condition. These units appear to have no operational problems. We recommend that the units remain in service. A chemical treatment flush of their heating and cooling coils will be provided as discussed under the recommendations for hydronic equipment.

These AHUs are connected to the existing first generation Trane Tracer Summit control system, which is compatible with the current third generation version of the control system. If upgrades are made to the DDC system, the existing controllers can be reused and reconnected.

PAINT BOOTH MAKEUP AIR AND EXHAUST SYSTEM

Air handling unit ASU-1 and exhaust fan AEF-1 are beyond their service life, and are no longer used. According to Lane County staff, there are no plans for future use of the Maintenance Building paint booth. Until use in the space changes, the unit can remain abandoned in place, and no work is recommended.

CABINET UNIT HEATERS

Four cabinet unit heaters (CUHs) remain, two of which are no longer operational. CUH-6 and CUH-7 have been abandoned in place and replaced with electric unit heaters. CUH-6 and CUH-7 will be removed as part of heating water piping replacement as discussed under the recommendations for hydronic equipment. CUH-5 that serves the Facilities Services, room 444, appears to have reduced capacity from system corrosion, and is beyond its service life. Replacement with a hydronic unit heater is recommended. CUH-4 is a supply air unit with an electric duct heating coil. It was intended to provide minimum ventilation air and freeze protection for the paint booth room for periods when the makeup air and exhaust system was not operating. Since the paint booth is no longer used, CUH-4 is the only system providing

M023.01 Systems West Engineers, Inc.

Conditions Survey Section 3-10

conditioned air for the paint booth. We recommend that CUH-4 remain in service until the paint booth room use changes.

ELECTRIC UNIT HEATERS

Two electric unit heaters (UHs) have been installed to replace non-operational CUH-6 and CUH-7 in the sign shop storage areas; rooms 450 and 451. The UHs are relatively inexpensive and straightforward to replace. We recommended that the UHs be replaced by maintenance staff as they fail.

EXHAUST FANS

Two of the four existing Maintenance Building rooftop exhaust fans, REF-1, REF-2, CEF-7, and EF-3 are in poor condition and will need to be replaced. Replacement of REF-1 is included in the scope of work to upgrade the central air handling system as discussed in section 3.1.2.2. The remaining two rooftop exhaust fans, EF-1A and EF-2A, are newer and in good condition and will remain.

FUME HOOD

The fume hood exhaust fan located in the testing area hallway adjacent to room 415 appears to be in good condition, and use is intermittent. Refurbishment of the hood and associated exhaust fan UEF-1 is recommended including inspection, cleaning, and replacement of bearings and belts if needed.

RECIRCULATION HOOD

The recirculation fan located above the ceiling of room 407 is of good quality and has significant remaining life. Refurbishment is recommended including inspection, cleaning, and replacement of bearings and belts if needed.

Recommended replacements, changes, and upgrades discussed in this section include:  Replace cabinet unit heater CUH-5 with a hydronic unit heater.

 Replace exhaust fans REF-2, CEF-7, and EF-3.  Refurbish the fume hood and exhaust fan UEF-1.  Refurbish recirculation hood fan unit CEU-1.

The approximate construction cost for HVAC work in this category would be $20,200. 3.1.3 Administration Building

Again, a variety of fans, terminal units, and hydronic systems serving the Administration Building have failed, do not operate properly, or have reached the end of their useful service life. Replacement or refurbishment of considerable equipment is necessary to provide adequate comfort, appropriate ventilation, and improved reliability. Recommended upgrades for specific equipment are described in greater detail below.

3.1.3.1 Hydronic Systems

The condition of the Administration Building hydronic system is virtually identical to the Maintenance Building, and general recommendations are the same. A summary of

recommended changes and upgrades follows:  Demolish pumps HWBP-1 and CWBP-1.  Demolish cabinet unit heater CUH-1.

 Replace all heating and chilled water piping 2-inch in diameter and under.

 Replace all hydronic isolation valves, strainers, pressure relief valves, automatic air vents, gauges, and other trim.

 Provide a system flush and water treatment of the heating and chilled water systems, including:

o Initial system flush including installation of a temporary bypass to isolate the Maintenance Building.

o Installation of a basket strainer to catch debris

o Circulation of a chemical mixture designed to scour corrosion products from the heating and chilled water piping.

 Flush existing cooling and heating coils in HVU-2.

 Provide testing, adjusting, and balancing for chilled and heating water coils in the Administration Building.

The approximate construction cost for HVAC work in this category would be $37,400. 3.1.3.2 Central Air Handling Systems

The central air handling system is also very similar to the system serving the Maintenance Building, and general recommendations are essentially the same. A summary of recommended changes and upgrades follows.

 Remove the existing roof above mechanical room 619 to facilitate removal of existing air handling unit HCU-1 and return fan BF-1 and installation of the new air handling unit and return fan.

 Install a new air handling system with the following features: o Economizer damper section

o Filter section with replaceable MERV 11 filters o Heating water preheat coil

o Chilled water cooling coil

o Supply fan with VFD and inverter rated motor o Return fan with VFD and inverter rated motor o Discharge plenum

 Cut an opening in the concrete exterior wall of mechanical room 619 and provide a new outside air intake louver

 Provide an exhaust air duct through the roof with roofcap.

 Provide new sheetrock, ceiling joists, sheathing, insulation, and standing seam metal roofing to repair the opening made during construction.

 Reconnect heating water and chilled water piping.

 Connect the existing hot and cold deck supply ducts to the new AHU discharge plenum.  Provide new return ductwork in the mechanical room to connect the existing return air

ductwork to the new return fan.

 Refurbish existing outside air booster fan BF-2 and associated exhaust fan CEU-1: o Replace drive belts, sheaves, and bearings.

o Clean and balance fan wheels.

o Remove rust and repaint areas with minor corrosion damage.

M023.01 Systems West Engineers, Inc.

Conditions Survey Section 3-12

 Provide VAV terminal units with heating water reheat to replace existing dual-duct terminal units in core zones or zones with moderate exterior exposure and heating load.  Provide fan-powered VAV terminal units with heating water reheat to replace existing

terminal units in high ceiling areas and zones with large exterior exposure and heating load.

 Remove pneumatic controls throughout, and provide new direct digital controls for all central fan system components.

 Provide testing, adjusting, and balancing services for the new air handling system, outside air booster fan BF-2 and all terminal units associated with the new system.

The approximate construction cost for HVAC work in this category would be $434,200. 3.1.3.3 Secondary Air Handling Systems

Recommendations for replacement or refurbishment of the Administration Building secondary air handling systems are discussed on a system-by-system basis below.

COMPUTER ROOM COOLING UNIT

The existing computer room cooling unit, AC-1, is at the end of its service life. Replacement of AC-1 and associated hydronic piping, valves, and trim is recommended. Work includes:

 Replace AC-1 with a similar unit. The unit would be resized to meet current and expected future loads if needed.

 Reconnect chilled water and domestic water piping.  Provide new valves, strainers, gauges and other trim.  Provide testing, adjusting, and balancing.

The approximate construction cost for HVAC work in this category would be $43,700.

BREAK ROOM UNIT

In our opinion, existing break room heating and ventilating unit HCU-2 can be refurbished and returned to service. Recommended work includes:

 Refurbish HCU-2:

o Replace drive belts, sheaves, and bearings. o Clean fan cabinet.

o Clean and balance fan wheels.

o Replace the unit condensate pan if required.

o Remove rust and repaint areas with minor corrosion damage.

 Remove pneumatic controls throughout, and provide new direct digital controls for all fan components.

 Provide testing, adjusting, and balancing (TAB) services for HCU-2, including rebalancing all spaces served by HCU-2.

The approximate construction cost for HVAC work in this category would be $9,500. 3.1.4 Fleet Services Building

A discussion of recommended upgrades, replacements, and refurbishments of existing systems and equipment follows.

3.1.4.1 Hydronic Systems

The condition of hydronic systems in the Fleet Services Building is similar to the Maintenance Building, and many general recommendations are the same. Two significant differences involve the radiant floor systems and existing piping installed during the 2003 mechanical system upgrade for office spaces.

The radiant floor systems are constructed with soft copper piping. The piping appears to be intact and operational to some extent. However, given that piping is at the low point of the system, it seems highly likely that radiant piping is partially blocked by debris in the system. This is most apparent in the heavy equipment areas where, reportedly, systems do not provide adequate heating during cold weather. We expect that flushing radiant systems to remove debris would allow the systems to deliver close to original capacity.

Piping and air handler coils installed during the 2003 addition are probably also in acceptable condition. Again, however, piping and coils should be flushed to remove debris and ensure that coils are clean and do not become re-contaminated.

Recommended changes and upgrades include:

 Remove main building chilled water booster pump CWBP-1 and heating water booster pump HWBP-1.

 Replace radiant heating system pumps HWBP-4 and HWBP-5.