[Bldg-sim] [Ibpsausa] DOE Job Task Analysis for EnergyModelers: Open for public comment until Nov. 28th

[Michael A. Eustice]

My experience is different than yours Varkie.  We often need to simulate buildings to a high level of accuracy (too high in my opinion) in order to obtain state and federal rebates and incentives.  An entry level designer will most likely not be able to hit those targets and I would even say most staff level engineers would have a difficult time.   It takes some senior level engineering to understand how the building systems operate; what is a normal result; and most importantly, how the program is going to react when the inputs are changed.

I guess if the output reports are not reviewed with any scrutiny and the targets have a wide range of acceptance, you could hand it off to an entry level engineer.  But hitting an electric and natural gas utility bill, month-to-month and a yearly overall, simultaneously within +/- 10% accuracy will take a senior level understanding.  Also, it’s not the time that is important as much as the ability to do it.  The cost to my company for my time to perform the simulation is irrelevant compared to the rebates and incentives that will be unavailable, and as a consequence the construction project that won’t move forward,  if the simulation can’t be performed.

Michael

From: bldg-sim-bounces at lists.onebuilding.org [mailto:bldg-sim-bounces at lists.onebuilding.org] On Behalf Of Varkie C Thomas
Sent: Friday, November 18, 2011 11:29 AM
To: Jeff Haberl
Cc: Kendra Tupper; ibpsausa at lists.onebuilding.org; Building Simulation
Subject: Re: [Bldg-sim] [Ibpsausa] DOE Job Task Analysis for EnergyModelers: Open for public comment until Nov. 28th







I don�t think there is need for �sponsoring a project to develop (1) job task analyses (JTAs), which identify and catalog all of the activities a worker performs in a given job; and (2) the knowledge, skills, and abilities (KSAs), which define the minimum requirements necessary for a person to adequately  perform those tasks, for the following six commercial building job categories: - Energy modeler - Operating engineer/building technician - Building energy auditor - Energy/sustainability manager - Commissioning/retro- commissioning practitioner - Facility manager�.



A JTA is not required for US President.  Energy analyst is not equivalent to a surgeon.  Life is not at stake.  But there is a need for such a document for education and certification.



At large A-E design firms the task of using energy programs is usually assigned to mechanical engineers who have recently graduated because engineering theory is fresh in their minds.  The programs are based on physics and engineering theory.  A 1 or 2 year graduate program would save the A-E design firm of the expense learning this subject on the job.



However a program like eQUEST can be used by someone with little knowledge of theory.  It is like driving a car without knowing the theory of internal combustion engine.  The analogy should be the car designer and not the driver.  Education (not 3 day seminars but 2 year graduate programs) and certification are important but so also is design experience to perform the energy analysis within a full understanding of the building life-cycle process.



Why is there so much emphasis on building energy modeling and simulation?  The importance of this work is exaggerated.



The results of energy programs are not used in design and therefore not used in construction and operation. Energy program results are used to compare alternative design options and make decisions when selecting envelope, systems and plant.  They are also used to show energy code compliance and for sustainable buildings certification.



A-E design affects the building products & equipment selected, construction and operation.  Design decisions are also based on * first & maintenance costs; * reliability & durability of systems, plant and equipment;  * ease of operation and maintenance; * availability of parts & maintenance staff at the location; * environmental impacts.



Given a set of drawings, schedules and specifications, two expert users of the same energy program will come up with different results.  The same person using different energy programs will have different results.  The results of energy programs for energy code compliance and for sustainable buildings certification are rarely checked with the completed building performance in operation.  I cannot find this information for any energy program.  There is also no information of which energy program was used for a LEED certified building and for all buildings that now have to comply with energy codes.



California and Florida had energy codes before the year 2000.  Most other States introduced energy codes after 2000.  10CFR434 is not stringent.  Computer energy analysis before the year 2000 was rarely done but the buildings were designed for efficient energy use by reputable A-E design firms. ASHRAE Std. 90.1 describes standard existing practice (except the 40% windows) by A-E design firms.



One million sqft office bldg (40 stories, 25,000 sqft/floor) in a large city downtown (including the land) costs $250 million at $250/sqft.  The A-E design fee is 3% or $7.5 million.  At an average A-E labor cost of $100/hour (including overheads) the design time is 75,000 hours. Energy analysis of an office bldg using eQUEST or TRACE takes about 100 hours (2.5 weeks at 40 hours/week) or 0.13 % of A-E design time or 0.004% of total building cost.



The importance of building energy analysis is inflated.



Varkie Thomas













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