CEE 243 - Predicting and Measuring Building Energy Use Agenda: May 26 Original class overview  Introductions  Motivating problem  Course overview / roadmap  Today’s lecture: intro to HVAC systems  Wednesday: Building performance database introductionQ8 1. For each assigned system and a few associated points for each:  System or component description, e.g., AHU1 or Hot Water Supply Temperature  ID, e.g., 1127  Point source, i.e., one of: Control, Sensor measurement  On one or a small set of SEE IT graphs of 2011 measured CEE 243 May 26 2Q8 2. Re Query 7 … elaborate your analysis of significance.  Estimate the CO2 abatement potential of some change that you suggest that might make the predicted data either better or worse: Plot ∆$ vs. ∆CO2  Assume: – Change: ~ $1000, $10,000, $100,000 – 1.3 lbs CO2 to generate 1 kWh electricity; – 125,000 pounds CO2 to generate 1 billion Btu; – 12,000 Btu for 1 ton of heating or cooling.  Annotate business significance in plot. CEE 243 May 26 3Q8 3. SEE IT graphs that represent system performance from the perspective of one or a small set of related points. Identify the important features and implications of each graph and of comparisons between related graphs 4. Add a title for each section of your wiki w/ green/ yellow/ red light status. 5. Add a Guide for users page to your wiki that explains how to: Browse, … 6. PowerPoint deck for final presentation CEE 243 May 26 4Lingo  Enthalpy: – total energy of a thermodynamic system [joule; Btu, calorie]  Heat – Latent and sensible: – Sensible heat changes temperature – Latent heat changes state, e.g., gas , liquid – In air conditioning, sensible capacity lowers temperature; latent capacity removes moisture from air CEE 243 May 26 32Lingo  Infiltration: – air leaking into or out of a building through cracks, frames, outlets, walls, floors, roof, etc. [Air Changes per Hour (ACH)]  Units – IP vs SI: – IP: inch-pound – SI: Systeme Internationale, i.e., metric  Air wall (air curtain): – A narrow stream of air directed across an opening to deter the transfer of hot or cold air, contaminants, and insects from one side to the other, e.g., in grocery store refrigerator cases CEE 243 May 26 33Lingo  Models – Design and analytical: – Design models describe, e.g., 2/3D graphics – Analytical models allow analysis  Space boundary: physical barriers to energy flow between spaces – 1st Level: depend only on building elements – 2nd Level: depend on spaces behind the boundary, typically a subdivision of first level space boundaries CEE 243 May 26 34Lingo  Transmittance: – Measure of ability of anything to transmit radiation: transmitted / incident flux [%]  Plenum: – Enclosed space in a structure that allows air movement, typically for return air CEE 243 May 26 35Lingo  R-value: – Measure of thermal resistance (inverse: conductivity) – Heat loss per m2: ∆ Temperature / R value  U –Factor: – Heat transfer through glazing (function of temperature) [BTU/ sq. ft./hr. degrees F]. T – Lower U-Factor = better the glazing insulation CEE 243 May 26 36ORID - Objective: What facts did you see this quarter? What factual statements can you make based on the data?  e+ GUI difficult  2011 results better than 2009  Problem types – sensor – system  If we change objectives, we can meet them CEE 243 May 26 37ORID - Reflective: What surprised you? What encouraged or discouraged you?  It is difficult to figure out if something works – to diagnose problems  Data sample intervals and sampling durations matter – a surprise  We got better with practice  Y2E2 has an admirable intent but the reality does not match  question of what hope we have  Lab downstairs uncomfortable (184)  Amount of bad data, often from sensor problems  Ambiguity – we needed to make our own assumptions 38ORID - Interpretive: What sense to you make of what you did this quarter?  You (we) can make a difference in performance with real effort  Looking at the $, people pay attention  Free (student) labor helps (or has been crucial for) Stanford with analysis CEE 243 May 26 39ORID - Decisional: What are our proposed next steps? What is your action plan for next steps?  Get a job  Need to be very smart to do the work – it is complex  Update data manual  Communicate findings to owners and future students  Try to leave a product of class more of what we would liked to receive CEE 243 May 26 40CEE 243 May 26 41 Recommendation: Predict and Measure