Result sheet - The assignment of REM/Rate software PDF

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The assignment of REM/Rate software by working with a completed model, the Building File report and the HERC Performance report...

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48752 Intro to REM/Rate Modeling Spring 2017, REM/Rate v 15.3, Assignment 1 Name: _Fauzan Wassil__________________ Due Tuesday in class: this assignment sheet, the Building File report and the HERC Performance report. This assignment will introduce you to REM/Rate software by working with a completed model. You’ll also use your understanding of heat loss and gain and the building envelope to make improvements to this home design. 1. Download and save the assignment file (REM1.blg); be sure to notice where you save it. Open the file in REM/Rate. If you get any pop-up messages when you open it about adding new equipment or materials temporarily to the library, click yes to all. I added assemblies to the software library for this project and left the original library entries intact. Since you’re going to be modifying the file, you may want to change the file name now so you preserve the original file. Note: the spreadsheet and notes screens are optional tools. You may want to minimize them when you’re not using them. 2. Get familiar with the software and the model by reviewing the current entries. Use the pointing hand icon at the bottom of the screen to advance through the screens. On the 4 th screen, Site Information, click on the button with 3 dots to the right of Miami, FL. The new screen that opens shows you the climate information for Miami. This is also the screen you’d use to change the location. a. On the right, you’ll see HDD and CDH. What does CDH mean? CDH is cooling degree hours. b. How would CDH differ from CDD? The difference would be the accuracy of cooling load will be much detail by using hourly data (CDH) 3. When you’re done, hit OK or Cancel in the location selection screen to close it. Move to the next screen, General Building Information. Click on the Building tab (word) at the top of the software and look at the drop-down list. This shows you the full range of main screens REM/Rate contains. You can navigate through the software with the pointing hand buttons OR can use the drop-down list to move from one screen to another. a. Describe the home as it currently exists: the dimensions, framing, building envelope, windows, size, and mechanical systems.   

Conditioned floor area: 2250 sqft Area of walls: 600(S), 600(N), 240(W), 240(E) - U-value: 0.08. Area of windows: 180(S), 180(N), 90(W), 90(E). U-value: 0.36, SHGC: 0.45 for double-pane lowe

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Area of ceiling: 2250 ft2 - U-value: 0.036. Heating system: Natural gas-fired air distribution furnace, 32kBtu Cooling system: Air conditioner, 60kBtu Hot water system: Conventional water heater, water tank 40 gallons

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b. Where is the thermal boundary? (hint: notice the “location” entry at the bottom of every screen that describes part of the building envelope). The bottom thermal boundary is above basement, (unconditioned basement) and the top is in the attic ceiling. 4. Check how this baseline model is predicted to perform by clicking on the lightning bolt icon just above the entry screen to get a quick energy analysis at the right. a. What’s the total annual energy consumption of this home in million BTUs? 60.9 MMBtu b. What are the annual heating and cooling design loads? 0.0 MMBtu (heating) and 100.7 MMBtu (cooling) c. What’s the difference between the Design Loads, the Annual Loads, and the Annual Consumption? Give the meaning of these, not the quantitative info listed on the screen. If you have questions, you can use the “?” icon to open REM/Rate help. d. How much are annual energy costs estimated to be, based on the utility rates entered? $1,591 5. There are tabs at the bottom of the energy analysis: the other tabs are Area and Compliance. Click on each tab to see what information is shown. a. What is the Window to Wall Area ratio? 32.1% b. Window to Floor Area ratio? 24% c. What is the current HERS Index for this home? Is this a good home for 2017? Explain your answer. HERS index is 98. According to Resnet website, the average HERS index for residential in Florida is 68 (2015), so 98 is not a good number. 6. Before you being to upgrade this model, see how the software can help you understand its performance. Click on the Reports tab at the top of the software, then click on New View/Select Reports. The screen that opens shows you all report options. If you click on the “Group of Reports to Consider” drop-down on the top left, you’ll see that you can narrow your choices by energy reports, code reports, graphs, and ratings. To view one or more reports, you click on it and Add it to the Selected Reports screen, hit OK, then view the results. Review the reports to understand which components of the home contribute most to energy consumption and costs. a. List the reports you found most useful to understand the home’s performance and, next to each report, describe what you learned from it.  

Building File Report – It covers almost everything basic about the building’s info and performance eval Hers Report – It is useful to see the comparison of the scores

7. You’re going to begin modifying the model to improve it. To become familiar with how the software entry works, let’s try a couple of changes. From the Building tab dropdown list, go to Above Grade Walls. You’ll see that this model has a wall for each orientation. Some modelers don’t do this, but this approach helps when you have more complex geometries and when you want to explore alterations for particular orientations. 2

In the main Above Grade Wall screen, you can see the U-value for each wall, but you don’t see anything about its construction. For one of the orientations (AWS, AWN, AWE, or AWW), click on the button with 3 dots next to the wall type. You’ll see the “Quick Fill Site Built” entry screen with details about the wall construction. For this assignment, you can use this screen to make modifications rather than using the “Path Layer” approach. Let’s say that you want to add some additional cavity insulation to this wall. It has 5.5” stud depth and is only using 3.5” now for R-13 insulation. You could get R-19 insulation in this cavity. In the upper part of the screen, “Miami Wall” should be highlighted. Click copy and paste to create a second version of this wall (so you can preserve the original). Change the name of the second version to Miami Wall 2 (or something similar). Change the cavity R-value to 19 and the cavity insulation thickness to 5.5. While you’re in this screen, also check what the “insulation grade” means, using the help key. Hit Okay when you’ve made your changes. Be sure to change the wall for each orientation! a. Now do a quick energy analysis check (lightning icon) to see if this change helped. If so, save the modified file and list the new energy performance, cost and HERS Index here. If not, you can reverse the changes or go back to the original file you saved. VERY IMPORTANT: REM/Rate does not save more than one version of a model in the same file so it’s important to save the file with a new name every time you make a change that you want to keep. If you don’t want to keep a change, reverse it before you continue. Your challenge for this assignment is to make 4 changes to the file to improve its energy performance and HERS rating and/or lower cost. Three (3) of these changes must be changes to the assembly (foundation, floor, walls, windows, roof, airtightness). The 4 th can be a change to one piece of mechanical equipment. Every time you make a change you like, save the file to a name you recognize indicating that change. 8. If you retained the above-grade wall change you made above, you may want to double-check the reports to see whether any of your planned 3-4 changes have shifted. Then, proceed with the other modifications you want to make. For each change, list the specific changes you made and its impact on annual energy consumption, energy cost, and HERS score. If any of your changes results in an Error or Warning at the bottom of the screen, you need to clear these before you proceed. Ideally, you’ll test each change separately so you know the impact of each change. Then combine all 3-4 changes in one file to show the final home performance. a. Change 1 and its impact: Above-Grade Wall into SIP 12-3/8” with U-Value of 0.018  Annual Cooling Loads: 96.5 MMBtu/yr, Annual Consumption: 59.8 MMBtu/yr  Annual Energy Cost: $1,566/yr, HERS Index Score: 96 b. Change 2 and its impact: Window and Glass Door into Double ref Clear Arg with U-Value of 0.320 and 0.12 SHGC plus complete adjacent shading for summer  Annual Cooling Loads: 70.5 MMBtu/yr, Annual Consumption: 52.9 MMBtu/yr  Annual Energy Cost: $1,405/yr, HERS Index Score: 72

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c. Change 3 and its impact: Ceiling into R-50 Blown, Attic with U-Value of 0.02, Reflective roof colour and Radiant Barrier  Annual Cooling Loads: 99.2 MMBtu/yr, Annual Consumption: 60.7 MMBtu/yr  Annual Energy Cost: $1,586/yr, HERS Index Score: 93 d. Change 4 and its impact: DHW Equipment into 40 gal. 0.95EF Electric Water Heater  Annual Cooling Loads: 105.7 MMBtu/yr, Annual Consumption: 57.3 MMBtu/yr  Annual Energy Cost: $1,521/yr, HERS Index Score: 97 e. Final annual energy consumption, energy cost and HERS score with the 3-4 changes you made:  Annual Cooling Loads: 53.6 MMBtu/yr, Annual Consumption: 43.6 MMBtu/yr  Annual Energy Cost: $1,202/yr, HERS Index Score: 66 9. If you have any unresolved problems with the software or questions about what you did, please list them at the bottom of your answer sheet. For Tuesday, bring to class to hand in a hard copy of this assignment sheet with your answers, a hard copy of the “Building File Report” (3nd from the top when you list all reports), and a copy of the HERC Performance (1) report (toward the bottom of the full list of reports). B&W copies are fine.

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