Plumbing and Mechanical Assessment
The following report on the building's existing plumbing and mechanical systems is by John Greenlaw, P. E., Principal of the Greenbusch Group, Seattle. It documents conditions observed during his site visit to the Snohomish Carnegie Library on October 6, 2004:
The purpose of our visit was to determine the condition of the mechanical system and identify the scope of work of any repairs or modifications that we would recommend to condition the historic building.
Existing Plumbing Conditions
Domestic water service is indicated to be 1-1/4” and enters the Carnegie Library on the west side. The service splits just downstream from the meter to serve the original construction and 1968 Addition and is connected to the original building’s water supply at 1” and the Addition at 1-1/4”. The service could be separated at or near the curb by isolating the piping to each building and adding an additional water meter.
The sanitary sewer serving the Addition exits the building on the south side. The main cleanout for the existing building is located in the Men’s Room in the basement of the Carnegie Library. We plan on reviewing the original sewer card to determine where the connection to the original building might occur.
Roof drainage is by external rainwater conductors drained to splashblocks. The roof drains from the south side of the original Carnegie Library onto the roof of the 1968 Addition. There is significant ponding on the flat roof of the newer construction.
Domestic water piping appears to be mostly copper piping. Sanitary waste piping appears to be cast iron hub and spigot.
Domestic hot water is heated by an electric domestic hot water heater, located in the 1968 Addition. The domestic hot water pipe is not insulated as is required now by current energy codes.
Water pressure at the fixtures was average to good. Water flowed clear at the fixtures.
The plumbing fixtures all appear to be of a modest grade in both the Carnegie Library and the 1968 Addition. The condition of most of the fixtures is average primarily due to worn finishes. Faucets and trim are a mixture of various brands and types due to repairs made over the years.
The individual drains appeared to be mostly clear. Most fixtures drained relatively freely with the faucets running for an extended period.
We estimate that the system is operational, and could remain so for some time, but has exceeded its service life.
Renovating the plumbing system should be a high priority. Some of the domestic water piping may be able to be reused, along with some of the drain piping. Drains should be rodded out, and new plumbing fixtures provided to respond to the proposed rehabilitation plan.
Fire Sprinkler
The building currently has no sprinkler fire protection system. (A fire sprinkler is not required if the building is categorized as an A-3 Occupancy, but is required under an A-2 Occupany. - Architect's Note)
Existing Heating
Heating systems for both the original structure and the 1968 Addition building are electric. The Basement of the original building is heated by electric baseboard heaters with local wall mounted thermostats providing temperature control. Ventilation is by operable sash windows. The Restrooms and the Kitchen in the Basement of the Carnegie Library are ventilated through the operable windows; there are no exhaust fans.
The Upper Floor of the original building is heated by an electric fan coil heating system. The fan coil unit and ductwork are located in the attic and supply heated air to an arrangement of ceiling diffusers. The fan coil was recently replaced; the inspection tag indicates it was inspected in 2002, which would make this unit only two years old. Heating capacity appears to be adequate for the Upper Floor. However, the arrangement of the system is not ideal for air conditioning the space. Providing heated air through ceiling diffusers in this 17' tall space provides an opportunity for the air to stratify and remain at the ceiling without providing useful heating at the floor level. Ceiling fans have been installed to help push the heated air down to the floor level.
The current enclosed Work Space/Office under the Mezzanine does not receive any direct heat or ventilation.
The 1968 Addition is served by three electric fan coil units, which are located over the Restroom/Electrical Room core area. The 1968 Addition is separated into three temperature control zones served by each fan coil unit. These are the Work Room area on the north side of the Restrooms, the west side of the display area, and the east side. Heated air from the fan coil units is ducted to a system of ceiling diffusers. The equipment is in reasonable condition considering its age and appears to have been regularly maintained. The location above the Restrooms is not optimum for maintenance because access is restricted.
The does not appear to be an outside air connection to the fan coil units to provide ventilation air. Although required by present code, it was fairly common in the 1968 era of construction to omit this.
Window glazing is thermally fairly inefficient in both the original and Addition.
Recommendations for Heating and Ventilation:
The following recommendations are intended to improve the building comfort, function and energy utilization.
General Recommendations
There are no major obstacles to separating the original Carnegie Library building from the 1968 Addition from a mechanical engineering standpoint. The two buildings share a water service that may be separated at the street. Domestic hot water is generated in the Addition, and a heater could easily be added to the existing building to make it stand alone. None of the heating and ventilation systems are combined between the buildings.
Plumbing
We recommend replacement of the building plumbing systems in both buildings after their separation. Domestic water piping should be replaced in the Carnegie Library to respond to a new arrangement of fixtures in insulated copper including the service entrance and piping throughout the building.
The domestic water heater should be replaced during this rehabilitation, and a water heater added to the original building.
Site sanitary sewer piping should be snaked to insure that there are no major root blocks or breaks. Some of the site sanitary piping may be clay tile which is prone to settlement cracking. Intermittent blockage may be anticipated in a building of this age. We will need to review original sewer records or have a locate performed to determine if the sewer connections need to be separated to create separate buildings.
The 1-1/4” service line is adequate to serve the newer Addition as long as a similar number and style of plumbing fixtures are utilized. The proposed rehabilitation calls for additional fixtures, however. A one inch service to the original building would support tank style fixtures. Flush valve fixtures would require an upgrade to 1-1/4” service.
Heating Recommendations
There are several options for modernization of the existing building heating systems.
1. After separation the systems in each building can remain as-is and repairs performed on-going and as required to maintain system operation.
2. Either one or both building systems could be upgraded and made more energy efficient by replacing the electric fan coil units with air to air electric heatpumps. Duct systems would remain the same and the fan coil units would be replaced by heatpump indoor units. Heatpump outdoor units would need to be situated within about 100 feet of the indoor units with this option. This option would also provide air conditioning but would not be optimized for it because of utilizing the existing heating distribution ductwork. Air to air heatpumps would reduce yearly energy consumption.
3. The heating system in the original building could be replaced with a system of hot water radiation for a more original appearance. A boiler could be situated in the original or new boiler room, and supply heated water to a system of cast iron radiators located under each window. This would be similar to style and appearance to the original system. However, the architect has indicated that historic style radiators are not necessarily a character-providing feature, and thus simpler, wall-mounted radiators could be provided. The boiler would be smaller and more efficient than the original and parasitic losses would be significantly reduced by using insulation. Radiant heating systems perform better than air systems in spaces with tall ceilings since radiation heats surfaces and not the air, but the ceiling fans should probably still be utilized with this alternative to reduce stratification.
4. New HVAC systems designed and optimized for both heating and air conditioning could be provided for both the original building and Addition. We anticipate the fan coils and ductwork would be replaced to respond to the anticipated cooling loads. The original building would be zoned for the Upper Floor and Basement, and served by separate systems. The Basement would be served by an arrangement of ceiling diffusers. The Upper Floor would probably be more optimally served by perimeter floor diffusers. Ductwork would be routed through the Basement in soffits to an equipment room on the north side housing air handlers for the Upper Floor and Basement respectively.
5. New mechanical equipment could be placed in the Basement or, with additional modifications, on the Mezzanine level of the Carnegie Library. Two new units would be adequate for the 1968 Addition and these could be located in the existing ceiling space above the service core in the 1968 Addition, to replace the current three units.
Acoustics
The Upper Floor conforms to a classic “shoebox” shaped performance space. Typical acoustical treatments for conventional theater are comprised of an acoustically absorptive back wall, and reflective clouds to reinforce stage program material. A shell is frequently added to reinforce vocal performances or electronic amplification is sometimes also used. A performance space can generate significant cooling loads due to lighting and patrons, and would argue for an air conditioning system to condition the space. AC will require additional electrical power and a ducted air moving system.
Miscellaneous
Power exhaust ventilation should be provided for the Restrooms.
The chimneys, if retained and reused by the heating system, should be relined. If abandoned and removed, the former vertical space could be reused for vertical chases.
The building insulation envelope should be improved wherever and to the greatest extent possible.
Any new suspended equipment and hot water tanks should be braced or strapped for seismic resistance.
Once the final program and architectural plan are selected we will provide more specific recommendations.
Mechanical record drawings can be found in the Appendix.
Foundation Board
Melody Clemans, president
Rebecca Loney, secretary
Anne Eason, treasurer
Greg Guedel
Dan Reynolds
Candace McKenna
Rosanna Sze
Leah Harrison
Fred Lighter, board consultant
Ex Officio Members
Dwight Knechtel
Elizabeth Grant
Bill Bates
Cathy Reines
Ed Poquette