eQUEST DETAILED EDITOR
Post-Wizard Shell Editing
- Add any missing upper level shell exterior walls.
- Import the following BDL code fragments from the eQuest library directory:
- Envelope_WSEC_Complaint.inp
- Envelope_ASHRAE_90.1G_Zone_4_Baseline.inp
- Assign the baseline envelope shell components corresponding to ASHRAE 90.1 Appendix G.
- Remove the roofs of lower-level shells where upper level shells are placed.
- Verify that the floors of the upper level shells are adiabatic; it may be helpful to separate the shells by temporarily specifying z-coordinates of 100 feet or more between them.
- Define air-walls between zones where appropriate.
- Specify the number of people per square foot under the 'Basic Specifications' tab of the Space Properties dialog box for each space.
- Do the preceding step now or else eQuest will calculate the people density for you, and it will be low
- Specify 31 persons for classroom, multiply the number of classrooms in the space, and divide by the total square footage of the space.
- Specify the maximum number of occupants of the school for gymnasiums, cafeterias, auditoriums and multipurpose rooms; scheduling will account for daily diversity.
- Specify 75 SF/person for administrative areas and libraries
- Specify 1000 SF/person for restrooms, corridors, and support areas; this will help to moderate outside air demands.
- Note that when the area per square foot is specified, and the number of people are reset to the default or 'green' value, this default value is calculated by eQuest to be the total area divided by the people factor per square foot.
- Renaming shells, spaces, zones and systems to improve the interpretability of simulation output and improve the accuracy of internal load factor assignment is best done at the beginning of detailed edit mode. The 15 minutes to half-hour spent doing this will pay great dividends going forward, for even modestly complex projects.
- Rename Shells: By default all shells are named "ELn Ground Flr", where "n" is the sequence number of the shell in the order in which it was added to the project. Rename the shell to something more descriptive like "EL1 Bldg 100" or "EL2 Second Floor" while retaining the shell designation prefix, which is used throughout the project by eQuest for the automatic naming of related components.
- Renames Spaces: In Component Tree view, next rename spaces for each shell to something more descriptive. For example, a group of classrooms may be automatically named "EL2 North Perim Spc (G.N1)"; rename to something like "EL2 Classrooms North Space", retaining the shell designation prefix and adding the "Space" suffix.
- Renames Zones: Switch to the Air-Side HVAC tab. Starting at the top of the component tree, double-click on each zone and rename it corresponding to its space. For instance, continuing the previous example, rename "EL2 North Perim Zn (G.N1)" to "EL2 Classrooms North Zone"; note that the corresponding space is listed in the properties dialog box of the zone for easy reference.
- Renames Systems, Single-Zone: For packaged single zone systems, rename the system to correspond to the zone. For instance, continuing the previous example, rename "EL2 Sys2 (PSZ) (G.N1)" to "EL2 Classrooms North Sys"; note that the corresponding zone is listed in the component tree view below the system for easy reference.
- Renames Systems, Multi-Zone: For multiple zone systems, rename the system to a using a general geographic designation. For instance, continuing the previous example, if the system type of "EL2 Sys2 (PSZ) (G.N1)" is changed from 'packaged single zone' to 'packaged multizone', the automatically assigned system name will not be changed by eQuest. Hence change the system name to something like "EL2 Multizone North System"; with the name selected to enable easy recognition when reading DOE2 reports.
Post-Wizard System Editing
- Specify minimum CFM per square foot values for each system under the 'Flow Parameters' subtab of the 'Fans' tab of the Air-Side HVAC System Parameters dialog box for each system.
- Do the preceding step now, or else eQuest will calculate the value for you, and it will be low.
- Specify 1.3 CFM/SF for classroom, administrative and other high-occupancy areas
- Specify 1.0 CFM/SF for gymnasiums, cafeterias, multipurpose rooms and corridors
- For cooling-only systems, remove the drybulb economizer lock-out. The default is 65°F, which is OK if mechanical cooling is provided. However to reduce the number of unmet load hours in natural, displacement and conventional ventilation systems without mechanical cooling, this constraint should be removed.
Using spreadsheet view, set Daylighting to 'No' for all zones, for the baseline case.
Create the following four parametric runs in the "working copy" of the project after it has been saved with all shell & envelope modifications captured:
Envelope Improvements
Lighting Improvements
Daylighting
Demand Ventilation
Others may be added, specific to each of the particular systems studied, after the working copy of the project is saved in system-specific versions.
Any 'Appendix G' baseline generally does not require parametric runs. [more detail]
Note: This is a work-in-progress procedure, additional details forthcoming time permitting
Doors & Windows
Generally custom door and window placement should be accomplished in Wizard mode. The following procedures may be useful when doors and windows need to be defined in detailed edit mode.
Assure that the total area of the windows does not exceed total wall area, else an error will result. This is problem can arise particularly on all glass stair towers, entryways, and corridors where the wall is essentially all glass. To prevent this from happening, the following user expressions may be used for positioning and defining the width and height of "glass wall" windows:
X = 0.1
Y = 0
HEIGHT = {PARENT("HEIGHT")}
WIDTH = {PARENT("WIDTH")-0.2}
(NOTE: When entering user expressions into the Detailed Edit dialog, include only the portion of the expression to the right of the equal sign, and enclosed within but not including the curly braces)
The following expression may be used to center doors and windows in the parent wall:
X = {PARENT("WIDTH")/2-LOCAL("WIDTH")/2}
The following expression places doors or windows centered on the one third or two thirds points from the origin of the parent wall, respectively:
X = {1*PARENT("WIDTH")/3-LOCAL("WIDTH")/2}
X = {2*PARENT("WIDTH")/3-LOCAL("WIDTH")/2}
Use the following expression to create windows of a fixed height as wide as the parent wall:
WIDTH = {PARENT("WIDTH")}
Use the following expression to right-justify doors and windows:
X = {PARENT("WIDTH")-LOCAL("WIDTH")}
Editing Windows Frame and Spacer: In order to eliminate window frames, first go to the Building Shell mode and click on Spreadsheet. While on the Component Tree tab, click on one of the windows (i.e E1 South Win).
Change the Frame Width of the window to default (zero) - this can be done easier and faster using multi-edit if you working with thousands of windows. Next, change the frame spacer type from the default 'Aluminum' to 'Insulated'. Write-up UltraEdit method using regular expressions.
Schedules
Follow this link for schedule sharing. Implement common schedules now so you don't have to do it 3 or 4 times going forward.
Fan Schedules
After implementing the schedules sharing, the "Fan Schedules" in the Fan Power and Control tab needs to be adjusted. The Cooling should be set automatically to ESM Fan Sch after the schedule input; however, the Exhaust tab will still be empty. ESM Exhaust Fan Sch need to be selected in the Exhaust tab.
Simulations
Change the TITLE, LINE-1 parameter at the beginning of each baseline INP file.
Rename systems appropriately (e.g. PVVT, PSZ etc.) to for instance, GSHP using UltraEdit (expound).
Noted if system name is changed via GUI or inp, any reference to the system name in the parametric run definition (.prd) file must be changed manually, most easily via text editor.
Run trial simulation for each system type.
Eliminate any errors (e.g. 'LOOP has ZERO FLOW') to obtain valid trial simulations.
Examine .SIM output file for each valid trial simulation, and update .INP file to eliminate warnings and errors.
Exceptions: __ warnings are insignificant (list).
Run the 'Annual Energy Consumption by Enduse Report' for the baseline for each system (need graphic).
The lighting, misc. energy usage, ventilation, domestic hot water and ___? should all be the same.
If not, there is a variance in the energy densities or scheduling...correction needed.
Posted by Brandon Nichols at 10:48 AM 0 comments
Friday, October 31, 2008
eQuest Wizard Checklist
Topic: eQuest requires that once "detailed editing mode" is entered, changes can no longer be made using the "wizards", else detailed edits are lost.
Since it is important to be sure that all edits that are best done using the wizards are complete before moving on to detailed edit mode, use the following checklist as a guide (and please comment if items need to be added, deleted, or modified). For purposes of the checklist, "screen numbers" refer to individual screens within each of the "Design Development Wizard" components.
In general, building geometry, zoning and schedules are best specified within the wizards. Also, detailed window placements are somewhat easier in the wizards. When a point is reached in wizard editing where geometry and zoning are well defined and will not be changing in a thermodynamically significant manner going forward, then the wizards may be left behind in favor of the detailed editor.
Items that are more efficiently accomplished by the wizards are noted in the following checklist.
DESIGN DEVELOPMENT WIZARD COMPONENTS
Components of the design development wizard are accessed from the Project Navigator screen. Click the buttons on the left of the Project Navigator screen with titles in bold below to access the screens referenced in the checklist.
Project / Site / Utility
Project location data and weather station. Be sure to specify this information correctly upon project initiation.
Input the basic project information (Screens 1-7) including weather, utility and schedule data.
Be sure the utility data is correct! Going forward, this is not easy to change via the detailed edit interface; it is however easy to change using a text editor.
Be sure the schedule data is correct! eQuest creates a multitude of schedules and changing them individually in the detailed editor is a tedious affair. Use the following as an example of a typical schedule for a school in Washington State, note 'Full Nine Months, No Summer Session" selection in the first dropdown:
(click on the image to see a larger version)
Edit Session #2 to eliminate spring break; this will bias annual energy consumption figures conservatively and provide a load profile curve more consistent with expectations.
If the project contains any existing buildings, then be sure to get the ball rolling to obtain historical utility bills!
Historical utility bills are valuable without substitute to calibrate the energy model.
Releasing the historical utility bills requires owner approval, and the process may take a week or two.
Suggest e-mailing the owner's project manager the release request, and cc'ing the utility company contact.
The owner's project manager simply needs to 'Reply to All' to authorize.
Edit Selected Building Shell
(Envelope Components)
Screen 1: Entered general information & be sure to enable daylighting by selecting 'Yes' from the Daylighting Controls drop-down (this option will be unavailable for below-grade shells).
Screen 1: Entered the area of the shell, or the total area of all multiple shells, in the 'Building Area' field. This number defaults to 150,000 ft.², and is overridden by the actual area in many calculations. However as matter of good practice, use the number calculated from the AutoCAD area takeoffs. Be sure to do this before custom door and window placement. If this step is overlooked and doors and windows are placed, skip until detailed edit mode.
Screen 2: Use the 'custom' option to trace both building footprints and zones (Screen 2), using the zone outline drawing created from AutoCAD as a template. Trace the CAD files, refer to eQuest tutorial for instructions.
FOOTPRINTS
A Most Important Note for Multi-Shell Buildings: Be sure to start with the same vertex for each shell (i.e. footprint). This vertex ideally will be one that is X,Y common to all shells.
All other things being equal, the lower left-hand corner is a good choice. If you have an offset shell, where say the top floor is smaller than the bottom four, then for the top floor use as the first vertex the vertex closest to the first vertex of the main shells.
Organizing footprints out of the gate saves valuable re-work time going forward when it comes time to line up the shells and stack them into a coherent model.
Remember, all wizard-defined zoning data and custom window/door placements ARE LOST if a shell (i.e. footprint) is subsequently moved or re-sized.
You will not fully appreciate the gravity of the preceding statement until such time that you lose a day or two's worth of pre-deadline production work.
ZONES
Regardless of where the interior walls fall, be sure to trace the outline of any pop-ups, clerestories, gymnasiums, band/music rooms etc. which rise above the surrounding roof lines as zones.
Be sure to split up lower-level zones to assure that lower- level zone boundaries fall coincident with upper-level shell perimeters.
Lastly, assure that large zones such as corridors are split into separate zones where daylighting is a potential.
Doing so enables the selected zones to:
Be easily specified as multilevel in the next step,
Simplifies the deletion of extraneous roof components in detailed edit mode, and
Makes the definition of daylighting zones more accurate in detailed edit mode.
Be sure to do this now, modifying zone definitions and splitting roofs in detailed edit mode is painstakingly tedious!
In general, mechanical penthouses and mezzanines may be ignored.
Screen 2, cont'd: Be sure to specify any multi-level zones by clicking on the "Zone Characteristics" button and working through the ensuing dialogue. Doing so will raise the roof and the extrude exterior walls of the selected zone.
Screen 2, cont'd: Specify the floor-to-floor height as 12 or 14 feet in general for single-story and multistory structures respectively. Specify a floor-to-ceiling height equal to the floor-to-floor height in order to eliminate nuisance plenums.
Screens 3-6: Accept the default values.
Screen 7: Change shade depths to 0 ft. for all exposures, unless shading is known to exist is part of the design, and clear the 'has overhang' checkboxes.
Repeat the preceding steps for each shell!
Edit Selected Building Shell
(Internal Load Factors)
Screen 8: If daylighting is to be considered for any core zones, add skylights where appropriate. Be sure to add skylights for any perimiter or core zone that has clerestory-type skylights.
Screen 11: Verify the zones to be modeled for daylighting.
Screen 12: Verify the building operational session break down is the expected three sessions (Breaks, School in Session, No Use Summer); if not, go back to the Project/Site/Utility module and correct it now. Then use the following time of day operation schedules for schools in Washington state:
Breaks: 'Closed' every day.
School in Session: 7am - 4pm weekdays; secondary 6am-5pm weekdays; closed weekends.
School in Session schedules have been increased 1 hour at the beginning and end the day over actuals to increase the simulated heating load, which is typically low when compared to utility bill actuals.
No Use (Summer): 9am - 2pm weekdays; closed weekends.
Screen 13: Activity areas are defined by the general function of the space. eQuest is limited to eight activity areas in the wizard, which is generally sufficient for the high-level analysis of a typical educational facility. A suggested predefined activity area selection for schools is as follows:
Classrooms/Lecture
Corridor
Exercising Centers and Gymnasium
Dining Area
Kitchen and Food Preparation
Office (General) or Library (stacks)
Auditorium or Library (reading) or Mech/Elec Room
Restrooms
Screen 14: Zone groups may be defined by the type of system which will serve them. Using this approach, "Classroom Systems", "Administrative Systems", "Single Zone Systems" and "Exhaust Only Systems" will cover the majority of schools.
Screen 15: For schools in general, check the following 'Interior Enduses':
Interior Lighting
Office Equipment
Exterior Lighting (first floor shell only)
Domestic Hot Water (DHW)
Check 'Cooking Equipment' if a kitchen is present
Be sure all others are unchecked
Screen 16: While the 2006 Washington State Energy Code lists maximum watts per square foot values for lighting power densities by functional area (see list below), use 1.20 w/sf for all areas of a school as the baseline (blue denotes change from 2004 code).
Classrooms/Lecture: 1.2
Corridor: 0.8
Exercising Centers and Gymnasium: 1.0
Dining Area, Cafeterias: 1.0
Kitchen and Food Preparation: 2.0
Office (General): 1.0
Library (stacks): 1.3
Auditorium: 1.00
Library (reading): 1.3
Mech/Elec Room: 0.9
Vocational: 1.4
Restrooms: 0.8
Storage Areas: 0.5
Screen 17: Use the following values for office equipment loads, some adjustment may be for the necessary to bring the baseline EUI up to the expected value of between 40,000 and 50,000 BTU per square foot per year:
Classrooms/Lecture: 2.0
Corridor: 0.5
Exercising Centers and Gymnasium: 0.5
Dining Area, Cafeterias: 0.5
Kitchen and Food Preparation: 0.5
Office (General): 4.0
Library (stacks): 0.5
Auditorium: 0.5
Library (reading): 4.0
Mech/Elec Room: 0.5
Vocational: 5.0
Restrooms: 0.0
Screen 17: Click on the ellipses (...) button next to the load profiles, and edit 'Office Equipment S3' profile, which is the summer profile. Click on the maximum value at the right, and change it to '20'. Repeat for each day of the week by clicking on the load profile icons across the top of the screen.
Screen 18: For the kitchen area only enter the following values, using a sensible heat ratio of 0.5 for all entries:
Elementary: 15 W per square foot electrical and 200 BTU per square foot natural gas.
Middle Schools: 25 W per square foot electrical and 1000 BTU per square foot natural gas.
High Schools: 35 W per square foot electrical and 1600 BTU per square foot natural gas.
Screen 23: Use an exterior lighting load factor in watts per square foot such that when multiplied by first floor shell area, the result is the exterior lighting load in kilowatts. Lacking better information from the electrical engineer, 3 to 5 kW is a standard range for typical school buildings.
Screen 25: Accept the default value for domestic hot water (DHW).
Repeat the preceding steps for each shell!
Finish
(Check Schedule and Load Factor Assignments)
Click the 'Finish' button and temporarily exit the Project Navigator
As a check for proper schedule and load factor assignment, run a simulation and view the "Monthly Energy Consumption by Enduse" report, which may look something like this for a typical school projects without a kitchen:
(click on the image to see a larger version)
This profile is more typical of an elementary school project with a kitchen:
(click on the image to see a larger version)
If the load profiles look anomalous, inspect the individual components closely and review the steps above to determine the root cause of the differential, and edit the input data accordingly.
Future: Add EUI check example; EUI expected to be 40,000 to 60,000 BTU/SF per year.
Edit Selected Air-Side System
Restart the Project navigator and define all of the air-side systems that will be simulated.
Review the ELCCA Workplan and note the systems to be modeled in each of the alternatives.
Create a single representative air-side system type for all of the baseline system types that will be modeled in each of the alternatives:
Be sure to select "hot water heating" for one of the representative systems if a boilers is to be modeled in any of the alternates. This will assure that a boiler and hot water circulating loop are added to the model.
Similarly be sure to select "chilled water cooling" for one of the representative systems if a chiller is to be modeled in any of the alternates, to assure that a chiller and chilled water circulating loop are added to the model. Specify whether the chiller has a condenser water loop (less likely) or is air cooled (most likely).
Be sure to select ground source and water source heat pump system types at this time if they are to be modeled as one of the alternates. Specify cooling tower or closed-circuit fluid cooler at this time for the water source heat pump system.
Return to Screen 14 and assign the "baseline" system types to the appropriate zone groups.
The baseline system types comprise generally the lowest first-cost alternative.
In the simulation phase
The first simulation run will be the baseline alternate system types;
The project will be saved with the variant name to simulate the other alternates.
Adding all systems to be modeled at this time assures that they will be available when needed in the simulation phase.
Edit Selected Building Shell
(Custom Shell, Window & Door Placement)
Shell placement, Screen 1: Precisely place shell components relative to one another using the "Specify Exact Site Coordinates" checkbox. For example,
Specify the coordinates of the first floor as 0,0,0 and measure the distance from a common point (e.g. a common building corner) on the second floor shell to the first floor shell in AutoCAD.
Specify the XY coordinates of this measurement in decimal feet, and the height of the first floor as the Z-component of the second floor's site coordinates.
If the shells seem to be farther apart than originally, reverse the signs of the XY coordinates -- you may have measured in the wrong direction.
Custom window and door placement, Screen 6: Be sure to place windows and doors only after satisfactorily completing the previous steps. In other words, review all the steps above and be sure they have been completed before proceeding.
Do this now because once the windows and doors are placed, changing parameters such as the floor-to-floor height will cause all custom window and door placements to be lost!
Enter double-doors individually, to provide an accurate door count. The simulation report does not provide door square footage, just a door count. Thus for most facilities, door square footage may be estimated by multiplying the door count by a nominal 21 square feet per door. If the facility contains roll-up or other odd sized doors, then these must be accounted for individually.
Once windows and doors have been placed satisfactorily, you're ready to leave the Design Development Wizard behind and work in Detailed Edit mode for the remaining duration of the project.
