Temperature & Humidity Controls Folger Shakespeare Library Preserving the world’s largest collection of Shakespeare’s works Types of Spaces Exhibit Spaces (70F & 45%RH) Exhibition Hall (AHU7) Reading Rooms (AHU6, AHU14, AHU15) Founder’s Room (AHU8) West Wing Hallways (AHU8) Collection Spaces (65F & 45%RH ) Deck B (AHU2) Deck C (AHU1) STC Vault (AHU5) Art Vault (AHU5) All of these areas struggled to provide adequate temperature and humidity control in 2010. Seasonal setpoint changes : +/- 5 RH. IPI Consultation (Image Permanence Institute) Investigation Monitored existing conditions remotely Space conditions AHU conditions Outside Air conditions Onsite Coordination Duration was 1 year (2010-2011) All 4 seasons Recommendations Upgrade Controls Add chiller & AHU4 replacement Renovate 3 AHU’s AHU7 AHU14 AHU15 Implementation Immediate Changes Continue to monitored existing conditions Climate Liaison & Facilities Coordination Daily Operational Changes Tweaks to PM schedule Material changes Damper changes Initiate Phased Controls Upgrade Long-Term Changes Begin design phase with Mueller Implemented IPI’s recommendations Energy Management VFD’s and Heat Recovery chiller Specific DDC system (JC FX Server) Focus on collection requirements Dry Bulb Temperature the familiar “air temperature” measured by an ordinary thermometer which has a dry sensing bulb (displayed on horizontal axis) Wet Bulb Temperature – the temperature at which evaporation takes place (diagonal parallel lines) Psychometrics Relative Humidity expresses the air’s moisture content as a percent of its maximum capacity at its current dry-bulb temperature (displayed as a series of curves) The 100% rh curve forms the upper boundary of the chart (saturation curve). Psychrometrics Dew Point Temperature The temperature at which moisture will begin to condense from the air (move horizontally to the left to intersect the 100% rh curve). When the dry-bulb temperature of the air cools to the same value as the dew point temperature, the air is said to be “saturated” – it has reached 100% relative humidity. Psychrometrics Dew Point Temperature Air in the boundary layer near a cold surface gives up some of its heat to that surface. If the air cools sufficiently, it may fall below its dew point temperature, so it can longer retain all the water vapor it carried originally. The dew forms on the nearest surface, as shown in the photo. The surface temperature of the shaker is 32°F, and the dew point of the surrounding air is 60°F (80°F / 50% rh)° Psychrometrics Most dehumidification in commercial buildings is accomplished by cooling coils. Air is chilled low enough to drop its dry-bulb temperature below its initial dew point temperature. As the air drops below its dew point temperature, water vapor condenses on the cold surfaces of the cooling coil, and drains away from the air as liquid condensate Dehumidification Using Cooling Coil Dry Bulb Temperatures Dew Point Temperatures Outdoor Air Ambient Annual Conditions Rare Collections Conditions Rare Collections Outdoor Air Unit Rare Collections Chilled Glycol System Exhibition Hall & Reading Room Exhibit Hall & Reading Room Conditions Exhibition Hall & Reading Room AHU Schematics Current Status AHU7, AHU14, AHU15, AHU4, and supplemental chiller have been completed. Including new equipment and controls. T&B and Commissioning have been completed. Replacement of Primary Steam Convertor Installation of multiple hot water reheat coils to assist with recovered heat from chiller Phased Controls Upgrade Upgraded main master controller Upgraded all AHU controllers Upgraded all defective sensors or valves Tied in all stand alone DX units, dehumidifiers, and humidifiers Currently upgrading all steam convertor sensors and valves. To be completed in March. Delivery of new Clean Steam Generator tomorrow Replacement of many smaller components. Continuing Efforts Software Modifications Full range of management Seasonal reset schedule Deficiency Alarms Heat recovery chiller Seasonal Set point changes Hot Water Loop (Steam Convertors) Upcoming Mechanical Upgrades Replacement of 6 Steam Convertors Replacement of additional hot water reheat coils Replacement of AHU5 (Summer 2015) Continue to upgrade all defective sensors or Commissioning of AHU6 & AHU8 valves Questions? David Conine, Head of Facilities (202) 608-1705 [email protected] Todd Garing, Vice President (410) 646-4500 [email protected]
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