Blackstone Building 10A Progress Report March 13, 2006

1
Blackstone Building 10A Progress ReportMarch 13,
2006

• Demi Ajayi
• Lauren Broughton
• Florence Evina-Ze
• Rotimi Okunade
• Alex Paddington
• Matt Smith

2
Outline for Todays Update

• Site visit status
• Building envelope
• Experiment plan
• Sunload model refinements
• Heat balance calculation for 10A
• Heat balance calculation for Ops Center
• Dynamic heat transfer model

3
Site Visits

• Visits to Blackstone MWF afternoons each week
  with Cate
• Each Blackstone team should send one member to
  collect data and reposition HOBOs
• Data collection using class laptop
• Serial-USB adapter

4
Envelope

• Control Volume of Building 10A
• Basement 42,520 ft3
• 1st Floor 54,330 ft3
• 2nd Floor 54,330 ft3
• Total 151,180 ft3
• Square Footage 4,360 ft2 per floor
• Total 13,080 ft2

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Envelope

• Surface area of windows and brick walls on each
  exposed side of the building

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Envelope

• R-value of 10As walls

Sources www.coloradoenergy.org www.icynene.com
/InsulationSystem.aspx
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Experiment Plan

• Plan for HOBO placement based on the 4 HOBOs
  currently available
• We have requested 4 more
• Plan is easily scalable
• Ideally will be moved every MWF
• Will note outside conditions as well

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Experiment Plan

• Approach
• Take advantage of downtimes such as evenings,
  weekends
• Measurements must be independent of factors like
  construction activities, propane heaters
• Currently
• 4 hobos in 10A measuring stratification

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Experiment Plan

• Stratification
• Objective
• determine the vertical distribution of
  temperature on a floor in 10A
• Setup
• 4 hobos mounted at known heights on a pillar
• Take measurements over 1 day, 1 night
• Repeat for each floor, and at different locations
  within floor
• Purpose
• Empirical basis for stratification modeling

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Experiment Plan
1st Floor Example

• Stratification

4 HOBOs
Plans Omitted
11
Experiment Plan

• Temperature mixing between buildings
• Objective
• Determine the manner in which heat is transferred
  between the buildings
• Setup
• Heater in bldg 10B attached to timer, watt meter
• 1 HOBOs in 10B, 2 at interface, 1 in 10A
• Modulate heater, take data overnight or over the
  weekend
• Repeat for each floor
• Purpose
• Empirical basis for modeling mixing between
  buildings

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Experiment Plan

• Temperature mixing between buildings

Plans Omitted
13
Experiment Plan

• Temperature mixing within 10A
• Objective
• Determine the manner in which heat is transferred
  within 10A
• Setup
• Heater in bldg 10A attached to timer, watt meter
• 4 hobos mounted in bldg 10A
• Modulate heater, take data overnight or over the
  weekend
• Repeat for each floor
• Purpose
• Empirical basis for modeling mixing within the
  building

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Experiment Plan

• Temperature mixing within 10A

Plans Omitted
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Experiment Plan

• Others
• Repeat light intensity measurements on a sunny
  day
• Use IR thermometer to try and compute R-values
• Use thermocouples to try and compute R-values
• Concerns
• Use of a space heater overnight night at
  Blackstone (fire risk?)

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Suggestion

• Post data from HOBOs on the ES 96 website
• List Excel and .txt version of each log
• Comment beside each log with
• Date of data collection
• Group (i.e. 7, 10A, 10B, MD)
• Location (zone number on Blackstone Plans)

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Sunload Model Refinements

• Objective obtain hourly variation in solar
  radiation (Btu/hr/ft2) for each surface
• North
• South
• East
• West
• Roof
• Purpose incorporate this data into a dynamic
  model

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Sunload Model Refinements

• Three ways to get this data
• Collect it ourselves with an experiment
• Simulate the data using a model
• Use experimental data that someone else has
  collected
• What to do with the data once we have it

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Sunload model refinements

• First idea Collect data ourselves
• Record light levels at blackstone w/ Hobos
• Normalize by average sunload (NOAA website)

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Sunload model refinements

• Mather

N
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Sunload model refinements

• Second idea Simulate data with a model
• http//www.builditsolar.com/Tools/RadOnCol/radonco
  l.htm
• Inputs
• Day of the month
• Elevation angle (90 for walls, 0 for roof)
• Azimuth angle (0 for N, 90 for E, )
• 1 square foot collector area
• Latitude 42.3 (Boston)
• Altitude 0 ft above sea level
• Output
• Solar insolation in Btu/hr/ft2 per hour

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Sunload model refinements

• South-facing, by month

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Sunload model refinements

• Winter, by direction

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Sunload model refinements

• Summer, by direction

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Sunload model refinements

• Action Items
• Continue to verify the models predictions
• Take more light-intensity data at Blackstone
• Incorporate into dynamic model

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Heat Balance

• Back-of-the-envelope calculation
• Look at net heat transfer for a fixed inside temp
• Purpose
• Can the valance units in 10A provide a
  comfortable internal environment during the worst
  external conditions?

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Heat Balance

• Assumptions and simplifications
• Entire building treated as control volume
• Model as a large, air-filled box
• Conduction and convection through eastern,
  western walls and roof only.
• Operations Center omitted (for now)

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Heat Balance

• Some of the numbers used
• Toutside 0 F (winter), Toutside 100 F
  (summer),
• Tinside 70 F
• houtside 4.4 Btu/hr/ft2-F, hinside 0.8
  Btu/hr/ft2-F
• Rroof 60
• Rwalls 12.1 (recall previous slides)
• Rwindows 2.0 (double-pane www.coloragoenergy.org
  )
• 109 people in building, each generating 341.2
  Btu/hr
• 39 valance units in 10A
• Heating 10,000 Btu/hr/unit (19 are capable of
  heating)
• Cooling -5,300 Btu/hr/unit (all 39 are capable
  of cooling)

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Heat Balance

• Results (winter)
• Valance units ON
• 330,000 Btu/hr net heat transfer into the
  building
• 125 F/hr rate of temperature increase
• Valance units OFF
• 140,000 Btu/hr net heat transfer into the
  building
• 53 F/hr rate of temperature increase
• Therefore even in the winter without heating,
  people will want to open windows

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Heat Balance

• Results (summer)
• Valance units ON
• -9000 Btu/hr net heat transfer into the building
• -3 F/hr rate of temperature increase
• Valance units OFF
• 200,000 Btu/hr net heat transfer into the
  building
• 75 F/hr rate of temperature increase

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Heat Balance (Ops Center)

• Back-of-the-envelope calculation
• Look thermal load from equipment versus cooling
  capacity of Ops Center HVAC (labeled AC-1 on
  plans)

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Heat Balance (Ops Center)
Courtesy of www.apc.com
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Heat Balance (Ops Center)

• Thermal load from equipment
• Preliminary figures based on tour of chilled
  water facilities in SC basement
• Currently confirming quantity and type of
  equipment with Ops Ctr manager
• 18,000 Btu/hr (computers, monitors, racks, etc.)
• Cooling capacity of HVAC
• 148,400 Btu/hr (according to plans)
• Therefore surplus of cooling capacity

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Heat Balance (Ops Center)

• Additional modeling work for Ops Center
• Deduce interactions between ops center control
  volume and rest of 2nd floor
• Temperature stratification and spatial
  distribution
• Humidity

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Dynamic Heat Transfer Model

• Treat the building as one big air-filled box
  (oversimplification at first)
• Look at average temperature
• Incorporate same aspects as the steady-state
  calculations above

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Dynamic Heat Transfer Model

• Governing equations
• where

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Dynamic Heat Transfer Model

• The Point
• Simulate cooling or heating cycle
• See which control algorithms yield the best
  efficiency, comfort
• Accomplished so far
• Extremely simple version implemented (single
  temperature-dependent heat source)
• Uses Euler method to solve the ODE

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Dynamic Heat Transfer Model

• To do (by next meeting)
• Incorporate additional heat sources (like the
  heat balance Demi showed)
• Improve ODE solver
• To do (by spring break)
• Incorporate humidity
• Add multiple control volumes