L21366/101 090 00.00/Page 1 HVAC EXECUTIVE SUMMARY The North Middlesex Regional High School has received average maintenance of the HVAC systems over its occupied years. Even with adequate maintenance, through normal operation systems do gradually deteriorate due to scale, poor water conditions, and lack of preventive maintenance. Systems will gradually deteriorate to a point of exceeding their maximum serviceable life. This building is a typical example of one such project. While generally speaking, most systems are operating and maintaining reasonable space temperature control, but due to the antiquated nature of the mechanical systems and their gradual scaling of the various piping systems, heat transfer rates have become reduced and the overall system is taxed to a point of inefficiency being created by the slowly depreciating system. In addition automatic temperature control appears compromised due to failed controls and equipment, and ventilation rates and acceptable air-quality are compromised due to the progressing surface contamination on many systems as well as mis-adjusted and closed outside ventilation dampers. While there are no catastrophic failures obvious with the present equipment, the piping systems are suggesting a developing condition which could present itself as a major failure due to poor return water flow in the condensate system. The systems could continuously be repaired and modified on a sectional basis that will keep the systems operating maintaining space temperature control however, continued operation will be at the expense of increased operating costs due to inefficiency in heat transfer and through the generally antiquated nature of the systems themselves. All systems installed within this building have exceeded their maximum serviceable life and are in need of replacement. With overall repair, maintenance, cleaning and calibrating of the system, a continued limited service could be achieved however, unpredictable at best. Mechanical System Condition Survey Boiler Room The boiler room is provided with three (3) H.B. Smith 650 mills cast iron sectional boilers. Each boiler generates low pressure steam which is distributed to the various heating apparatus at a pressure of between 5 and 10 psi. Two burners are provided with dual fuel and the third is provided with a gas only burner. As it presently exists, a gas service is installed to the boiler room however, the power plant generally operates utilizing number two fuel oil with the gas only boiler very rarely used. As we understand it the burners for the dual fuel applications are configured to operate as oil only. Each boiler is provided with dual low water cut offs and all operating and safety controls which do meet current building code requirements. It is our understanding that one single boiler is capable of maintaining the entire facility on typical winter days with a second the boiler operating only during the coldest times of winter. Boiler No. 3 was installed approximately 35 years ago and is considered to be in poor condition at this time with various nipple leaks and shell corrosion indicated throughout. Boiler No. 2 is an original boiler when the power plant was built in 1960.
L21366/101 090 00.00/Page 2 This boiler is showing severe signs of wear and near failure as evidenced by multiple water stains around the base of the boiler, multiple nipple leaks at each of mud drum, rupture stains around access doors to the fire box, and overall deterioration on and around the boiler itself. Boiler No.1 is an original boiler when the power plant was built in 1960. This boiler is noted to be in very good condition on the exterior showing no signs of leakage or general deterioration as indicated above in boiler number 2. As we understand it this boiler is rarely used for reasons we are unclear on. The two (2) boilers installed during the original construction combine to a single common header located over the boilers where various zones originate and run out to various heating points within the original building. During the 1970 addition, a secondary header was installed over boiler number three which back feeds into the original header essentially creating a common distribution header feeding all points of the entire building. Breeching from boilers is through a welded black steel ducting system which appears to be covered with either calcium silicate or asbestos insulation with a canvas jacket. The boilers are provided with induced draft fans which assist in the flow of combustion gases from the boiler to the chimney, as well as barometric dampers to adjust for atmospheric conditions on the chimney. It was noted that there was excessive surface contamination on each draft fan. The breeching discharges into a masonry chimney which is vented vertically through the building to the exterior. There was no water staining or cracks on the surface of the chimney and the chimney was provided with a clean-out door. We could not determine if a flue liner was in place however, the overall size and height of the chimney appears adequate for the combustion gases discharged. All steam piping throughout the entire boiler room appears to be schedule 40 black steel with the laterals insulated with fiberglass insulation however the valves and fittings appeared to be insulated with asbestos. There was no evidence of leakage on the piping with only minor leakage noted on valve bodies. The condensate piping also appears to be schedule 40 black steel insulated with fiberglass insulation on the laterals and the valves and fittings appeared to contain asbestos. Many sections of piping at the rear of the boilers as well as around the boiler feed water system have had their insulation removed. Discussions with maintenance personnel has indicated that although the piping has not been a major source of concern over the years there could be evidence that various sections of the piping are beginning to leak as evidenced by lack of condensate flow back to the feed water system. It also appears that the condensate system could be blocked with sediment also interfering with adequate condensate flow back. It was not possible to determine an exact condition of the existing piping at this time. In order to maintain an exact interior pipe condition various sections of pipe should be removed and examined for interior erosion or sludge. Considering the light weight piping used in the condensate piping system, we have serious concerns as to the actual integrity of this piping system and more than likely it has reached its maximum serviceable life. In recent years the traps on the heating equipment have been replaced throughout the building which has reduced energy consumption however, in a number of applications particularly around the air handling equipment and end of main drips, a fixed orifice non-mechanical trap was installed which also could be preventing adequate condensate flow back to the feed water system as well as contributing to the indicated steam discharge from various vents throughout the building.
L21366/101 090 00.00/Page 3 No. 4 fuel oil was originally installed for the power plant however, approximately 10 years ago the entire system was converted to number 2 fuel oil at which time a new double wall 12,000 gallon buried fuel oil storage tank was installed along with all supply and return piping installed in a secondary containment conduit. Two (2) individual gear pumps installed during the original construction transfer the fuel from the oil tank through duplex strainers and heat exchanger to where the oil is heated and distributed to the individual burners. What the burners do not fire is returned back to the fuel oil tank for redistribution. The heat exchangers located at the fuel oil transfer set are no longer used. Minor leakage was evident around the fuel oil transfer area, however; there were no signs of near failure. Distribution piping between the transfer set and the burners is through a schedule 40 uninsulated system located overhead. Minor leakage was indicated around the boiler burner unit, however; a system failure is not indicated. With the exception of the tank and buried piping the overall condition of the fuel oil transfer system would be considered poor. Condensate which is returned from the general building heating apparatus is collected in a floor mounted condensate receiver boiler feed water unit. Located under this storage tank are centrifugal pumps which provide feed water to the individual boilers through a feed water control valve on each boiler on a signal from the low water cut off switch in the boiler operating controls. We did confirm that this feed water system does operate adequately. The level controls located within the boiler feed water unit indicated a very low water level suggesting inadequate condensate flow back from the building. It would also indicate with his low water condition city water is introduced to maintain adequate feed water levels to each boiler. We understand that the city water is not chemically treated before its introduction into the heating system and if this is the case, the excess oxygen suspended within the city water could potentially be eroding away the interior of the piping systems. We were also advised that at the beginning of each day after the buildings have started water must be drained from the boilers to maintain adequate water levels. It is our understanding through maintenance personnel that this condition has existed for a long period of time which would give strong indications that the piping systems are more than likely near complete failure. The power plant is provided with a blowdown system which connects to each mud drum of each boiler and distributes to a floor mounted receiver tank which appears to be insulated with asbestos with a canvas jacket. As the condensate is transferred city water is mixed with the high temperature condensate where it is cooled and then removed from the power plant to drain. It appears that the city water cooling system in this condensate blowdown circuit is not operating. If this is the case, higher than allowed condensate temperature is discharging from the building to the sanitary sewer.
L21366/101 090 00.00/Page 4 Combustion air for the boiler room also appears to be inadequate. Located at the ceiling of the original boiler room is an air handling unit which is completely taken out of service. Located in the boiler room addition are two individual combustion air ducts one located high within the room and the other discharging to the floor each of which are provided with motor operated dampers. It does not appear that the motor operated dampers are operating. The overall size of the combustion air openings is inadequate for the total connected powerplant rating. The automatic temperature control is of the pneumatic design. Located within the boiler room is a single air storage tank with dual tank mounted compressors and motors which generates compressed air for distribution through a dual pressure day night control system. Located adjacent to the air storage tank is a refrigerated air dryer with oil water separators as well as pressure regulators. Compressed air circulates throughout the boiler room and the building thru a combination of copper tubing and polyvinyl tubing to the individual control devices. Located on an adjacent wall are automatic temperature control panels all of which was noted to be extremely antiquated and do not appear to operate. It does appear that this automatic temperature control system is original to the building and it was noted that the compressed air tank does have surface contamination and slight leaking, as does the adjacent control devices. Considering the age and antiquated nature consideration should be given to upgrading. Addition Building Mechanical Room Steam is distributed to the addition building through an underground trench system which appears to run throughout the existing building and into the new addition. Located within the mechanical room is a depressed mechanical pit adjacent to the incoming trench which allows steam piping to rise to the ceiling to feed various pieces of equipment as well as contains a condensate receiver tank with pumps to return condensate back to the boiler room. The tank is of the steel wall design insulated with what appears to be either calcium silicate or asbestos with a canvas jacket. The system is provided with a primary and standby discharge pump which discharges within the trench through a fiberglass insulated schedule 40 black steel condensate return pipe which terminates in the original boiler room. The tank and its associated pumps and controls was noted to be an average condition with slight surface soiling. It was noted that the vent pipe was discharging condensate which could be the result of bypassed steam from either failed steam traps or the incorrectly installed orifice traps. A direct source of low-pressure steam is provided to a floor mounted domestic hot water heater which is utilized year-round for domestic hot water distribution.
L21366/101 090 00.00/Page 5 Student Center The student center, which is the former cafeteria of the original building, is provided with six vertical discharge classroom unit ventilators located along the exterior of the space. Each classroom unit ventilator appears to have been recently installed and is provided with a lowpressure steam heating coil with valve control which ties into the existing steam distribution system located in a floor mounted trench, supply air through a vertical discharge grill, return air drawn at the base of the unit, filters, a direct expansion cooling coil which is circuited to an internal compressor and condensing cycle, and a direct source of outside ventilation air drawn through a wall mounted louver. Condenser air for air-conditioning cycles are also drawn through the same wall mounted louver. The overall condition of the equipment was noted to be very good however, the units were very noisy when they operate but are providing adequate total air circulation. Automatic temperature control for these unit ventilators are through equipment installed standalone electronic sensors installed at the time the unit ventilators were installed. All systems were operating satisfactorily. There were no central exhaust systems installed to facilitate the flow of ventilation air and as a result could be compromising be code required outside air requirement of the building code. Administration Area The administration area which is located in the original building is provided with a continuous length of fin tube radiation located along the entire exterior wall and is controlled by various wall mounted pneumatic thermostats in the individual offices. All of the radiation is fed from the overhead steam distribution system and the condensate piping runs at the rear of the fin cover and discharges to a mechanical pit in an adjacent mechanical room. A condensate receiver a located within this mechanical pit discharges condensate back to the boiler room. The overall condition of the fin tube radiation was noted to be very poor and was noted to have surface damage in surface soiling all of which was original and in general need of replacement. All thermostats were original and were extremely antiquated and questionable if any operate. The condensate receiver is extremely antiquated with excessive surface soiling and contamination also in need of replacement.
L21366/101 090 00.00/Page 6 Ventilation air for the entire administration area is through the use of operable windows located along the exterior wall. A central exhaust system which includes a roof mounted exhaust fan is provided to facilitate the flow of ventilation air through the windows, however; it is generally undersized for the area served as well has noted to be soiled. Although the percentage of openable area is adequate to meet the natural ventilation requirement of the building code it is not a recommended application and should be upgraded. The administration area is also provided with two vertical discharge 100% recirculation air-conditioning units one of which is located in the nurses area and the second located in the vault. Each unit is provided with a length of horizontal supply duct work which is uninsulated and serves at various wall and ceiling diffusers in the individual areas. Each unit is provided with a roof mounted air cooled condensing unit and is controlled by two individual electric wall mounted thermostats. Both systems were noted to be extremely antiquated, soiled, and the unit located within the nurses area was in a general state of disrepair as well as exposed to the general public. Both systems have reached their maximum serviceable life and are in need of replacement. Auditorium The auditorium is provided with a single heating and ventilating air handling unit, which is located above the ceiling of the auditorium at the rear adjacent to the projection room. The air handling unit is provided with a supply fan, filters, steam heating coil which ties into the overhead steam distribution system, return air which is drawn from two individual return air registers located approximately 8 inches above the floor under the air handling unit, and a direct source of outside air through a wall mounted intake louver. Supply air is provided to the space through an insulated galvanized sheet-metal distribution system to series of ceiling diffusers. It does appear that the amount of air provided to the space is adequate for the overall population. All grilles were noted to be slightly soiled, and original to the building approximately 35 years old. Considering the general antiquated nature of the supply system, as well as its age all systems appear to have reached their maximum serviceable life and generally in need of replacing.
L21366/101 090 00.00/Page 7 The stage area was not provided with any direct supply or exhaust ventilation air all of which is non code compliant. Located at the front of the stage in the auditorium area are two wall mounted exhaust registers which communicate to individual roof mounted exhaust fans through a galvanized exhaust system. As we understand it the exhaust fans were upgraded recently during a roofing upgrade project and do appear to operate however, we could not confirm if they were balanced to code conditions. Entrances, Vestibules, Corridors The individual communicating corridors were not provided with any supply or exhaust ventilation air all of which is non code compliant and should be improved upon. The primary and secondary entrances and exits throughout the building were not provided with vestibule interlocks to prevent infiltration of cold air during frequent use. This present condition is not code compliant under the current building code and is extremely energy wasteful allowing the large amount of cold air to enter the building which must be heated. Vestibule interlocks at all entrances and exits are highly recommended. The primary and secondary entrances were provided with convection heating which are extremely undersized. This condition is allowing cold air to filter throughout the corridor areas and affect overall building temperature control. Convection heaters were also provided throughout the communicating corridors and once the exterior doors are closed are adequate for overall space heating. The overall condition of all heating equipment in their associated thermostats is extremely antiquated, some of which are damaged, all of which are recommended for replacement. Classrooms The original building classrooms are provided with a vertical discharge classroom unit ventilator located along the exterior wall of the building. Each unit is provided with a supply fan which discharge is vertically into the space, steam heating coil with valve control which ties into a main steam line which travels at the rear of the classroom unit ventilator, return air drawn at the base of the unit, filters, and outside air drawn directly at the rear of the unit through a wall mounted louver. Each unit is controlled by a wall mounted pneumatic thermostat. The classroom unit ventilator and the thermostat are original to the building and were noted to be extremely antiquated, the unit ventilators were damaged and had severe surface soiling, the interior areas of the cabinets were extremely soiled, and it does not appear that the outside intake louvers are operating and therefore ventilation air is compromised below building code requirements. All equipment has reached its maximum serviceable life and is in need of replacement.
L21366/101 090 00.00/Page 8 Located on the interior wall of each classroom is a wall mounted exhaust register which communicates to a roof mounted exhaust fan through a series of galvanized sheetmetal exhaust ductwork. The interior of all registers were extremely soiled and all grilles were antiquated. It does appear that all roof exhaust fans were replaced during a recent re-roofing project and do appear to operate however, we have no assurance that code required amounts of ventilation air are being exhausted at this time. With the exception of the roof mounted exhaust fans all systems are extremely antiquated and are need replacement. Condensate is returned to a common condensate return line generally located above the floor at the rear of the unit ventilators in a wall mounted enclosure. As we understand it in recent years various sections of the condensate piping has been failing indicating corrosion and that the system is nearing its maximum serviceable life. The condensate collects at common points throughout the building and discharges into mechanical pits containing condensate receivers where it is discharged through a pressurized system back to the boiler room. All condensate piping is original and approximately 45 years old and with the apparent recent failures indicates the system has reached its maximum serviceable life and is in need replacement. The condensate receivers are provided with a primary and standby distribution pump however, all systems were antiquated and in need of replacement. The computer classrooms are provided with vertical discharge classroom unit ventilators located along the exterior of the space. Each classroom unit ventilator appears to have been recently installed and is provided with a low-pressure steam heating coil with valve control which ties into the existing steam distribution system located behind the unit ventilators in a wall mounted enclosure, supply air through a vertical discharge grill, return air drawn at the base of the unit, filters, a direct expansion cooling coil which is circuited to a grade mounted air cooled condensing unit, and a direct source of outside ventilation air drawn through a wall mounted louver. The overall condition of the equipment was noted to be very good however, the units were very noisy when they operate but are providing adequate total air circulation. Automatic temperature control for these unit ventilators are through equipment installed standalone electronic sensors installed at the time the unit ventilators were installed. All systems were operating satisfactorily, were clean, and in very good condition. The addition building classrooms are provided with a vertical discharge classroom unit ventilator located along the exterior wall of the building. Each unit is provided with a supply fan which discharge is vertically into the space, steam heating coil with valve control which ties into a main steam line located below the floor, return air drawn at the base of the unit, filters, and outside air drawn directly at the rear of the unit through a wall mounted louver. Each unit is controlled by a wall mounted pneumatic thermostat. The classroom unit ventilator and the thermostat are original to the building and were noted to be extremely antiquated, the unit ventilators were damaged and had severe surface soiling, the interior areas of the cabinets were extremely soiled, and it does not appear that the outside intake louvers are operating and therefore ventilation air is compromised below building code requirements. All equipment has reached its maximum serviceable life and is in need of replacement.
L21366/101 090 00.00/Page 9 The addition building classrooms were also provided with a cabinet exhaust fans located adjacent to the classroom unit ventilator which is designed to remove the code required amount of ventilation air. Each cabinet fan was noted to be soiled, some of which were damaged and it did not appear that any of these fans were operating. With the non operating condition of these exhaust fans the code required amount of ventilation air is not being provided at this time. The steam piping feeding the addition building is located throughout a series of floor trenches beneath the first floor level and feeds all equipment from this trench. All steam piping is schedule 40 black steel and appears to be insulated with fiberglass insulation. The condensate piping is also located in the same floor trench and returns by gravity to a central condensate receiver located in the addition building mechanical room where it is returned to the existing boiler room. All piping is nearing its maximum serviceable life and generally should be upgraded. Gymnasiums The original building gymnasium is provided with two horizontal discharge air handling units located at the ceiling. Each air handling unit is provided with a supply fan, steam heating coil which ties into the overhead steam distribution system, filters, return air drawn at the base of the unit, and outside air drawn in through a wall mounted louver. Each air handling unit discharges into a soffit area located over the dividing curtain, and through a series of wall mounted registers provides ventilation air to the entire space. It does appear that the amount of ventilation provided for the space is undersized by current building code requirements. With the return air opening drawn directly at the base of the air handling unit the close proximity of the supply and return is short-circuiting a percentage of the total air therefore compromising overall air quality and air volume distributed. Each air handling unit is noted to be original and does contain surface contamination. It does not appear that the outside air dampers are operable and therefore outside ventilation air could be compromised below building code requirements. All systems are extremely antiquated and have reached their maximum serviceable life and air and general need of replacement.
L21366/101 090 00.00/Page 10 Each side of the gymnasium associated with each air handling unit is a wall mounted exhaust register located approximately 8 inches above the floor. Each register is connected to a roof mounted exhaust fan through a galvanized sheetmetal exhaust system. The interior condition of each register was severely contaminated with dirt and debris. The exhaust fan is designed to remove the minimal amount of code required ventilation air. It does appear that the exhaust fan was recently replaced during a roofing modification however we cannot be certain of code required amounts of ventilation air are being controlled. The space was not provided with economizer relief to allow for higher amounts of outside air when outside temperature permits. The addition building gymnasium is provided with four separate air handling units located in mechanical mezzanines at four corners of the space. Each air handling unit is of the vertical discharge design and is provided with a steam heating coil which ties into the overhead steam distribution system, filters, return air, and outside air drawn into a wall mounted louver. It does appear based on the size of the equipment that the amount of the air is undersized and is not compliant with building code requirements. The supply registers of each unit were noted to have slight surface soiling and with the close proximity of the supply and the return a percentage of the overall volume of air is short-circuiting and therefore limiting overall distribution to the space which is further compromising overall air quality. It does not appear that the outside air dampers are operable and therefore ventilation air is not compliant with building code requirements. Based on condition and overall age of equipment, and the questionable design of the individual systems all systems should be considered to upgrading at this time The space was provided with exhaust air to provide minimum ventilation air requirements which is through four individual wall mounted registers located approximately 8 inches above the floor which communicate to roof mounted exhaust fans through a galvanized sheetmetal exhaust system. Each exhaust fan is sized to provide a minimum amount of code required ventilation air and as we understand it each fan was replaced recently during a roofing modification however we have no confirmation that the fans are balanced to allow building code required air volumes. The space was not provided with any means of economizer relief to allow higher amounts of outside air when outside air temperature permits.
L21366/101 090 00.00/Page 11 Locker Rooms The boys and girls locker rooms are similar and are each provided with two horizontal discharge classroom unit ventilators located at the ceiling of the space. Each unit is provided with a supply fan, steam heating coil which ties into the overhead steam distribution system, return air drawn at the base of the unit, filters, and outside air from a roof mounted intake hood. It does not appear that the outside air dampers are operating and therefore ventilation air is not in compliance with building code requirements. Each unit free blows into the space and with the close proximity of the return air to supply air, is short-circuiting a percentage of the total air therefore compromising overall air quality and ventilation air provided to the space. All units were noted to have surface soiling and contamination and some units were damaged. Based on overall condition and age all systems have reached their maximum serviceable life and are need of replacement The entire locker area is also provided with a central exhaust system which includes ceiling exhaust registers generally located over the shower and toilet areas which communicates to roof mounted exhaust fans through a galvanized sheetmetal exhaust system. All systems were noted to have surface soiling and contamination and all systems were extremely antiquated. Many systems located within the boys locker area were also damaged. It does appear that the roof mounted exhaust fans were replaced during a recent reroofing project and do appear to operate however, it does appear that the systems are undersized and are not in compliance with current building code ventilation requirements. With the exception of the exhaust fans, based on overall condition and age all systems have reached their maximum serviceable life and are need of replacement. Cafeteria Each cafeteria area is provided with three vertical discharge classroom unit ventilators to of which are located along the exterior wall of the building and one is located on interior wall. The combined volume of each unit ventilator does appear adequate to meet building code ventilation requirements. Each unit is provided with a supply fan which discharges vertically into the space, steam heating coil with valve control which ties into a main steam line which travels in a trench beneath the classroom unit ventilator, return air drawn at the base of the unit, filters, and outside air drawn directly at the rear of the unit through a wall mounted louver. Each unit is controlled by a wall mounted pneumatic thermostat. The classroom unit ventilators and the thermostat are original to the building and were noted to be extremely antiquated, the unit ventilators were damaged and had severe surface soiling, the interior areas of the cabinets were extremely soiled, and it does not appear that the outside intake louvers are operating and therefore ventilation air is compromised below building code requirements. All equipment has reached its maximum serviceable life and is in need of replacement.
L21366/101 090 00.00/Page 12 Located on the interior wall adjacent to the classroom unit ventilator are two wall mounted exhaust registers which communicates to a roof mounted exhaust fan through a series of galvanized sheetmetal exhaust ductwork. The interior of all registers were soiled and all grilles were slightly damaged. It does appear that all roof exhaust fans were replaced during a recent reroofing project and do appear to operate however, we have no assurance that code required amounts of ventilation air are being exhausted at this time. With the exception of the roof mounted exhaust fans all systems have reached a maximum serviceable life and should be replaced. Kitchen The kitchen is provided with a single canopy hood located over the entire cooking area. The hood discharges vertically to a roof mounted exhaust fan and is controlled manually by a wall mounted switch. The hood is provided with removable cleanable cartridge filters, vaportight incandescent lighting, and fire protection. The entire hood is of the single wall stainless steel design and is of the proper height and size to completely cover all cooking equipment. The hood was noted to be very clean and in very good condition. It was not possible to determine if the proper air volume is being exhausted through the hood however, we did note that there was no mechanical make up air provided and is could compromise adequate air volumes. It does appear that make up air was intended to come from the adjacent cafeteria areas however the amount of outside air provided in each cafeteria is in adequate to maintain code required make up air. Although no recommendations are made for the exhaust hood make up air should be provided to maintain code volumes of exhaust air. The kitchen area was provided with a horizontal discharge classroom unit ventilator located at the ceiling of the space. The unit is provided with a supply fan, steam heating coil which ties into the overhead steam distribution system, return air drawn at the base of the unit, filters, and outside air from a roof mounted intake hood. It does not appear that the outside air dampers are operating and therefore ventilation air is not in compliance with building code requirements. The unit free blows into the space and with the close proximity of the return air to supply air, is shortcircuiting a percentage of the total air therefore compromising overall air quality and ventilation air provided to the space. The unit were noted to have surface soiling and contamination and slightly damaged. Based on overall condition the unit has reached its maximum serviceable life and is in need of replacement.
L21366/101 090 00.00/Page 13 Woodworking Shop The woodworking shop is provided with a horizontal discharge classroom unit ventilator located at the ceiling of the space. The unit is provided with a supply fan, steam heating coil which ties into the overhead steam distribution system, return air drawn at the base of the unit, filters, and outside air from a wall mounted intake louver. It does not appear that the outside air dampers are operating and therefore ventilation air is not in compliance with building code requirements. The unit free blows into the space and with the close proximity of the return air to supply air, is short-circuiting a percentage of the total air therefore compromising overall air quality and ventilation air provided to the space. The unit were noted to have surface soiling and contamination and extensive damage. Based on overall condition the unit has reached its maximum serviceable life and is in need of replacement. The space is also provided with an overhead dust collection system which is made up of a galvanized sheetmetal exhaust system which connects to various woodworking appliances which is ducted to an exterior mounted duct collection system. The dust collection system is of the 100% recirculation design and is located directly outside of the building. The recirculation air defuses back to a storage room through a secondary filter where it is recycled back to the space. When the system does operate it is extremely noisy. Although antiquated and dirty the entire system does appear to operate and maintain reasonable dust control. RECOMMENDATIONS When considering the overall age and poor performance of the HVAC systems, their general state of disrepair, and for the most part a non operating automatic temperature control system, all mechanical systems should be replaced. We do not recommend upgrading the components of the systems on a sectional basis since the mechanical systems and their components work together as a single system and, as an example, changing the boilers without the piping systems, or the classroom unit ventilators without changing the automatic controls and the piping, would not experience the benefits of the investment of upgrading the components since a failure is eminent at any point within the existing components. Any interruption at any point in the system would essentially render the entire system inoperative, or poorly performing at best. As the building presently exists, there are no life safety concerns associated with the HVAC systems however, the building code has specific requirements relating to ventilation air of which is severely compromised within this building. It would be possible to manipulate the existing control system and air handling equipment to provide a limited amount of ventilation air possibly to meet minimum building code requirements however, we would not recommend this condition as a "fix" to the problem and only endorse this as a temporary repair.
L21366/101 090 00.00/Page 14 Because of the poorly performing automatic controls, more than likely energy consumption within the building is well above average when compared to similar buildings, and considering the general state of disrepair, maintenance costs and repair costs would also be considered above average. The only alternative to correct on a long-term basis the ventilation code deficiency, high operating costs, and high maintenance and repair costs, would be in overall system replacement utilizing energy conservation design techniques. Considering normal air-conditioning areas to include administration, cafeteria, media center, and auditorium would have an associated construction cost based on present day dollars to be approximately $ 22.00 per square foot.