Jessica P. DeBord Arch 491 GE: Chelsey Effinger Project 3: Wall Assembly 1) Opaque Wall Assembly (8 points) a) (4 points) Draw an annotated wall section (at 1 ½” = 1’ scale) that clearly shows all the Components See Appendix A for Annotated Wall Section b) (2 points) Provide an analysis that describes your intent. - - - - The intent of this opaque wall is to serve as a barrier for views and light for our studio spaces, as well as filter the heat and cold with the changing seasons. Since we live in a climate that is typically cold and rainy, I’m using the closed shell approach in this design. Wind: Sheathing the entire building in plywood, plastic film, 1” foam insulation, and siding, assuming they are properly installed, should be sufficient enough to deal with any winds in the area. However, envelope materials are subject to human error and can be left with holes if installed incorrectly. Rain: In addition to the use of overhanging roofs to protect the facade, the Humidity: A vapor barrier is applied to the outside of the warm side of the assembly, allowing humidity to equalize between the interior of the wall and the interior of the room. Heat: Both batt and solid foam insulation have been used. Solar Radiation: Wood is an excellent material in combating solar radiation, as it is poorly conductive. c) (1 point) Describe one ECS strength and one ECS weakness of your wall section. Standard light wood framing isn’t exactly the most efficient building system, I don’t know enough yet to look into advanced wood framing solution, but I do know there are more efficient systems than light wood framing. However, in an area like Oregon, timber is extremely sustainable, and timber framing, sheathing, and exterior finishes are all commonly used. This sustainable resource also doesn’t have to travel very far to get from its growth site to the construction site. This term in my studio I’m working with alternative materials, so picking a standard framing system serves two purposes for me - it allows my to establish a baseline that I can use to compare other wall constructions to, as well as giving me the opportunity to look at the most logistically viable and common building system used in the Pacific Northwest. d) (1 point) Discuss how you think your wall assembly will perform relative to minimum energy efficiency requirements and why. Working off of the International Building Code 2017 (IBC), I believe this wall assembly will perform above minimum requirements. The addition of rigid foam insulation and an air gap can significantly improve the R-value of a wall assembly and thus efficiency overall without adding too much labor cost to the overall constructions. I predict at least a 20% improvement from the IBC minimum standards. 2) R-Value (2 points) In a table format, assemble R-value data for each component of your wall assembly presented in Part 1. Material R - Value Wood Siding, 16 in., 7.5 in exposure 1.15 1” Foam Insulation, Expanded Polystyrene 5 Plastic Film Vapor Barrier 0 ¾” Air Gap 1 ½” Plywood Sheathing .62 5.5” Batt Insulation 21 ½” Gypsum Board .45 Interior Finish 0 Interior Air Film .68 Exterior Air Film - Winter .17 Total R - Value for Wall Assembly 30.07 3) U-Value (1 point) Calculate the U-factor for your wall, showing your work and units. U=1/ΣR U = 1/30.07 = .033 Btu/(hr)(ft2)(°F) 4) Embodied Energy (4 points) Calculate the estimated embodied energy for one square foot of your wall assembly. EECmat x Vmat= EEest Embodied Energy Coefficient x Volume of material per sq. ft. of wall = Estimated Embodied Energy per sq. ft. Material EEC x Volume/sq.ft. = EE Wood Siding, 16 in., 7.5 in exposure 37039.2 x 1 = 37,039.2 1” Foam Insulation, Expanded Polystyrene 2612605.6 x 1 = 2,612,605.6 Plastic Film Vapor Barrier - x .0625 = - ¾” Air Gap 0 x .75 = 0 ½” Plywood Sheathing 153525.8 x .5 = 76762.9 5.5” Batt Insulation 26034.8 x 5.5 = 143,191.4 ½” Gypsum Board 158087.6 x .5 = 79,043.8 Interior Finish - x .0625 = - Total R - Value for Wall Assembly = 2,869,599.1 Which component of your assembly contributes the most Embodied Energy? Is there an alternative material that would consume fewer resources while serving the same function? The foam insulation seems to be the biggest contributor to total embodied energy, but I’m also not sure I’m using the correct coefficient. That being said, making the wall thicker and using more batt insulation may be the more efficient solution, or using a hybrid system of fiberglass and something a little more dense in terms of r - value when weighing costs. 5) Windows (3 points) a) (2 points) Describe your thermal design intent for a typical window in your studio. Select a window product that you believe best meets this intent. Clearly describe the design of this product and cite the source of your information. Discuss how the window product meets your intents. The windows for our project should operate as switches between the interior and exterior environments. During the heating season, south facing windows can let light and heat into the space, while during the cooling season, windows on the north, as well as the east and west sides depending on the time of day, can be used to promote circulation and natural cooling. Beyond that, the windows should be positioned to frame views that can be pleasant year round, keeping in mind things like sun angles and glare. The window I am selecting to focus on is a Tafco 32” x 24” Awning Window. It features a vinyl frame that reduces the opportunity for thermal bridging around the window, and the window uses double pane insulated glass. The awning style opening provides an opportunity to create a protective overhang whenever the window is open, allowing the windows to be open while it rains. This can help keep things more comfortable on humid days, as well as just generally planning around Oregon’s less than consistent weather. b) (1 point) List the U-factor, solar heat gain coefficient (SHGC), and visible transmittance (VT) values for your selected window product. Identify data source(s). U-factor - .51 SHGC - .65 VT - .86 Source:https://www.homedepot.com/p/TAFCO-WINDOWS-32-in-x-24-in-Awning-Vinyl-Wind ow-White-VA3224/203164722 6) Calculating Material CO2e using the Athena Impact Estimator for Building Software Calculator (2 points) I couldn’t get the Athena program to work, so I used another source to get an approximate GWP number and the worked through the steps from there. Source:https://ac.els-cdn.com/S1877705817318374/1-s2.0-S1877705817318374-main.pdf?_tid= 2543ddd7-514c-4c60-95a6-fbcbd128b401&acdnat=1548850440_c0c3918f172e6d4c9d1de1d174 53a905 a) What is the total GWP (Material CO2e) of your wall assembly? GWP (Material CO2e) = 24.8 tons b) Convert this measurement to lbs / sf floor area. 24.8 x (2000 lbs / ton) / [192 sf] = 258.33 lbs/sf c) Divide your answer from (b) by the estimated lifecycle of the building (assume 60 years) in order to distribute your Material CO2e over the lifetime of the building. 258.33 lb/sf / 60 years = 4.31 lbs/sf/yr d) How does the Annual distribution of Material CO2e compare to the Annual Operational CO2 calculated in Project #1 Question 5.b? (The ratio of Material CO2e: Annual Operational CO2e is typically about 1:10) 4.31 : 104.38 Annual Material CO2e Annual Operational CO2e This was due to the incorrectly high power estimate from project one.
