Back From the Field

1
Back From the Field

• Team 10A
• A Work in Progress
• Demi Ajayi, Lauren Broughton, Florence Evinaze,
  Rotimi Okunade, Alex Paddington, Matt Smith

2
Long-Term Objectives

• Determine the efficiency of Buildings 7, 10A, and
  10B
• 10A in particular for our group
• Need to define efficiency
• Understand temperature dynamics in 10A
• Control algorithm ? Comfort? Efficiency?
• Modeling and simulation
• Suggest improvements?

3
Areas of Specialization

• Lauren
• Contact/Permissions
• Modeling
• Florence
• Materials/equipment
• Data acquisition
• Understanding the physical properties of the
  building
• Demi
• Main HVAC system
• Main control system/algorithm
• Modeling

4

• Rotimi
• 2nd floor Operations Center
• Operations center modeling
• Alex
• Sunload Modeling
• LEED Standards
• Envelope calculations
• Modeling
• Matt
• Modeling
• Integration (bldg model sun model control
  laws to simulation)

5
Contact/Permissions

• Emailed Cate Crompton at Blackstone on Friday
  2/17 still awaiting response
• Asked about
• Procedures for visiting the site
• Another site tour, either in one large group or
  smaller team groups
• Team meetings with Cate or another member of the
  Blackstone team to ask questions
• Sent list of preliminary questions

6
Envelope

• Consider surface area of all walls, windows,
  doors, etc.
• Measure the total area of brick walls, windows,
  other walls by floor and side of building
• Calculate the K-value for each of the surfaces

7
Physical Properties

• Determine wall building materials and their
  properties (R value)
• R values for gypsum (plasterboard) and brick have
  been found
• Need to find out what type of spray foam was used
• Can confirm these values at Blackstone by
  measuring the temperature difference on each side
  of the wall and plugging the values into the
  appropriate formulas
• Possible collaboration with other groups

8
Physical Properties

• Determine window manufacturer(s), model number,
  and properties
• Manufacturer Kawneer
• looking into the properties double-panes,
  coating, and leak rate
• Determine roof properties (insulation,
  reflectivity, etc.)
• Could not determine much from the plans but
  hopefully communication with Blackstone will help
  us learn about the roofs properties

9
Materials/Equipment

• Obtain valance unit specs
• manufacturer Edwards Engineering
• Coordinate with other groups regarding hobo units
• Contacted other groups and Xuan hobos are three
  to a group and ready for use
• Determine the heat output of a typical computer
• Heat output of a Dell Dimension computer ranges
  from 460.7 BTU/hr (485 kJ/hr) to 853 BTU/hr (900
  kJ/hr)
• need to find values for monitors, printers, etc
• need to find out usage profile and quantity of
  computers to be used in Blackstone

10
Valence Unit

• Manufacturer Edwards
• 2 pipe change over
• 3 way valve (motorized)
• hot/chilled water coil governed by zoned demand
  and outdoor temperature
• heating enter temp180 F, leaving temp 160F
• cooling enter temp 45 F, leaving temp 53 F
• Controlled by facility management system (FMS)
• Each contains temperature sensor

11
Control System Rules

• Building divided into thermal regions
• Each controlled by a change over circuit
• Valence units
• Heating/Cooling temperature control each
  modulated by control valve (controlled through
  sensor), to have set temperature of 70 F, 75 F
  respectively (adjustable).
• Unoccupied control 60 F (winter), 80 F (summer)
• Building level chilled water/hot water controls
• Radiator only circuit interior space cooling
• Heating outdoor temperature lt 55 F or gt2 zones
  in region call for heating
• Cooling outdoor temperature gt70 F or gt2 zones in
  region call for cooling.

12
Discussion

• Tasks
• Contact Christopher Schaffner (HVAC engineer) and
  Building Automation System Contractor (discuss
  details of plans)
• Obtain main ventilation system specs and plans
• purpose form foundation for modeling control
  system

13
Basement

• Plans Omitted

14
First Floor

• Plans Omitted

15
Second Floor

• Plans Omitted

16
Operations Center

• Own HVAC system with continuously running fan and
  chilled water supply manufactured by Liebert
• Unable to retrieve information about control
  system algorithm/sensor information in place
• Looking to Cate for information about equipment
  (placement, type and quantity)
• To schedule visit to current Ops Ctr in SC
  basement

17
Operations Center

• Fire rated 1 hr, specific info on floor
  insulation and material values still needed
• Occupancy for 2nd floor generalized to 136
  seeking projected space-by-space occupancy info
• Comparing current UOS utility costs to projected
  savings in Blackstone
• Thermal conductivity and specs of glass partition

18
Ops Ctr. Modeling

• Understanding DDC controllers modes of heating
  in relation to occupancy
• Building stratified into number of thermal zones
  how were those determined and how are they
  expected to interact with one another?
• In describing spatial distribution of heat
  especially between offices, identifying hot and
  cold spots in relation to Tset and effect of
  temp. control in offices
• Continued follow-up on peculiarities of Ops Ctr

19
Solar Radiation Modeling

• Look online for the website modeling solar
  radiation
• Develop a way to figure out the radiation (W/m2
  or Btu/ft2) that falls on a given face of the
  building at a given time of day, and how that
  changes seasonally
• Look up detailed LEED standards

20
Accomplishments so far

• Model of insolation on different faces of a
  building was found at http//susdesign.com/window
  heatgain/index.php
• Actual insolation data for Boston was obtained
  at http//rredc.nrel.gov/
• The model at susdesign.com showed the best fit of
  any model found to the actual data obtained and
  helps to assert the validity of the actual data
  obtained.

21
Sunload Modeling

• The average sun load for 4 different faces and
  the roof for each month was found and graphs such
  as the one to the left were plotted

Shows the average insolation power within each
month.
22
Sunload Modeling

• Data on the hourly variation of insolation on a
  horizontal surface in Boston was also obtained
  from http//rredc.nrel.gov/ and this will develop
  the real time model of sun load on any face in
  the building.

23
Sunload Modeling

• Using hourly variation in sunload data in
  addition to data obtained for monthly insolation
  totals, Matlab can be used to develop a model for
  sunload on any face of the building at any point
  during the day, at any time during the year

24
Thermal Load Model

• Based on the Adaptable Temperature Model from
  2002 ES 96 report on MD (see 6.1)
• 4 control volumes
• Basement
• 1st Floor
• 2nd Floor Operations Center
• 2nd non-Operations Center

25
Thermal Load Model

• From 1st Law of Thermodynamics
• where in our case,

26
Thermal Load Model

• Heat sources ()
• People t
• Computers/monitors t
• Light fixtures t
• Solar radiation (sunload model) t
• Variable sources ( or -)
• External walls (conduction convection) t
• External windows (conduction convection) t
• Ventilation airflow t?
• Leakage between floors (floorboards, stairwells)
  T
• VALENCE UNITS (where the control comes from) T

27
Thermal Load Model

• So the equation will go from,
• to something of the form,
• which can be solved numerically with MATLAB (see
  ode45)

28
Thermal Load Model

• Benefits
• Allows us to simulate the interaction between
  heat loads and the HVAC system
• Provides estimates of energy usage
• Drawbacks
• Control volume is a whole floor, so it only
  considers mean temperature (head in the oven,
  feet in the freezer -W. Yang)
• Macro-scale model will miss some micro-scale
  details

29
Looking Ahead

• Lauren
• Consider stratification and fan usage
• Funneling information as it is received from Cate
  to other groups
• Envelope calculations and modeling with Alex

• Florence
• Continued research into building and material
  properties
• Determining optimal utilization of devices for
  data acquisition

30
Looking Ahead

• Demi
• Understanding HVAC specs and functioning
• Locating sensors and current control algorithms
• Accounting for floor-to-floor and
  building-to-building air mixing

• Rotimi
• Continued follow-up on Ops Ctr data acquisition
• Describing spatial distribution of heat
  (horizontally) by identifying hot spots and cold
  spots
• Use of digital thermometers remote temp. sensing
  to understand properties of glass partition

31
Looking Ahead

• Alex
• Obtain hourly variation in insulation for each
  side of the building using Hobos.
• Develop data set of real time outside temperature
  (incl. apparent temp.).
• Modeling sunload and weather conditions in
  Matlab integration with building model.
• LEEDS criteria how are they met
• Work out way to measure efficiency of building.

• Matt
• Implement in matlab a small-scale, simplified
  version of the thermal load model to verify its
  feasibility
• Speak with other group modeling people to learn
  about their approaches

32
Questions

• How are other groups going to model the building?
  Will it be real-time, will it encompass an entire
  building or just specific rooms? How can the
  different groups work together to create a
  standard model?
• How should we define efficiency?