Project Location: City, Neighborhood, Site
Pasadena, CA
1411 N Oxford Ave. Pasadena, CA 91104
N. Oxford Ave.
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Project Location: Site Dimension
1.1
Dimension of Lot: 49.70 ft x 145.22 ft = 7,217.43 sq. ft
Length: 145.22 Ft.
Width: 49.70 Ft.
Project Model: Plan and Perspective
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4. 6. 5. 7.
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GROUND FLOOR 1. Living Room 2. Dining Room 3. Kitchen 4. Master Bedroom 5. Bathroom 6. Laundry 7.Bedroom 8. Patio
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Project Model: Elevations
North Elevation
South Elevation
East Elevation
West Elevation
2.1
Climate Analysis
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The average low is lowest in the month of February for my climate and the average high is highest in the month of September. My optimal shading for my South facing windows will have overhangs as opposed to louvers because through my studies, I have found that there was little to no difference in the amount of sunlight being let through the windows the entire day with either option.
Temperature Range Chart
Sun Shading Charts for December 21 to June 21
Sun Shading Charts for June 21 and December 21
Shading Optimization: South Windows
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According to the 2030 Palette. It directed me to face most of my glass to the South in order to maximize sun exposure. During my studies I also found that there was a big change in the amount of energy coming through my windows once I added overhangs. For the overhang the max was at 1.23 while it brings the max up for the base scheme to 1.86 (3.09 kBTU/Hr) This is because the overhangs are providing a substantial more amount of shade all day long.
Based on the Sun Shading Charts of summer and winter time, windows on the South need shade at noon at 60 degrees.
Shading Optimization
Shadows and Sunlight Analysis for Noon on June 21
4.1
The overhangs for the windows in the south facade provides enough shade during the warm days of the year for the windows (June 21 at noon)
The overhangs for the windows in the south facade do not stop the sun and let the windows have sun during the colder days of the year (December 21 at noon)
The west side windows are shaded by the garage so they do not receive the bad radiation in the afternoon of the warm days of the year. (June 21 at 5pm)
Building Envelope Optimization
Opaque High Mass Wall Assembly
The Psychometric Chart guided me to make decisions about the walls of my home. It directed me to utilize high mass walls which will work for 1,724 hours in my climate. l used concrete and brick because they are high thermal moss materials which will store and absorb heat for the coldest days which is 33.8 degrees.
Time Lag: 11.03 Decrement Factor: 0.28
Winter Design Low and Surface Area Design Summary
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R-Value: 22.68 U-Value: 0.045
September Wind Wheel
February Wind Wheel
Natural Ventilation and Cooling Analysis
Temperature Range Chart
Ventilation openings will work for the South and East walls in the hottest months because most of the wind is coming from the South and East. As for the coldest months, wind is coming from the East and the West .
Hottest Month: September Average High: 92 Average Low: 77
Coldest Month: February Average High: 65 Average Low: 44
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Natural Ventilation and Cooling Analysis
3D Results Hottest 12 day period and the impact on indoor temperature
6.1
This 3D result shows the 12 days in summer, left side indoor and right side outdoor, with closed window and no air circulation. At nights outside is cool but indoor has high temperature.
This 3D result shows the effective temperature of the 12 days in summer, left side indoor with open windows and right side the room without opening the window.
By opening the windows manually and adding a whole house fan we can easily balance the inside temperature in the warmest days of the year. The Lower graph is showing after opening the window the inside temperature was dropped from 87.36 to 81.81 which is truly effective.
Passive Heating and Mechanical System Sizing
Heating Peak Hour for February 31 at 1AM: Peak Heat Loss: -2,992 BTU/Hr Biggest Sources of Heat Loss: 1. Ventilation: -169 BTU/Hr 2. South Windows: - 723 BTU/Hr 3. Slab on Grade: -831 BTU/Hr 4. Roof: -573
HVAC Sizing Summary: The base Scheme Design Heat Loss was -11,641 kBTU/HR but with better insulation, the New Design Heat Loss is -8,236 kBTU/HR which got reduced 3,405 kBTU/HR so we can use an smaller HVAC system.
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Cooling System Sizing - Mechanical Equipment Sizing
Cooling Peak Hour September 31 12:00AM: Peak Heat Loss: -3,763 BTU/Hr Biggest source of heat loss: 1. South Windows: -897 BTU/Hr 2. East Windows: -439 BTU/Hr 3. Floor: -702 BTU/Hr 4. Roof: -660 BTU/Hr
A Slab on Grade where Ventilation Cooling is turned on. versus o Raised Floor with Tile Floor where Ventilation Cooling is turned on. Although these two schemes do not change the Home Energy Rating.
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Building Optimization Analysis Options
1. Window Optimization
Gross Total Site Energy 11.96 kBTU/sq .ft. Electricity: 11.96 Fuel: 0.00 PV Site Energy saved: -13.15 SHW Site Energy Saved: -3.62 Net Total Site Energy: - 4.85 kBTU/sq .ft.
2. Envelope Optimization
Gross Total Site Energy 2.49 kBTU/sq .ft. Electricity: 2.49 Fuel: 0.00 PV Site Energy saved: -5.54 SHW Site Energy Saved: -1.11 Net Total Site Energy: - 4.16 kBTU/sq .fl.
3. Night Flushing
Gross Total Site Energy 13.38 kBTU/sq .ft. Electricity: 13.38 Fuel: 0.00 PV Site Energy saved: -13.39 SHW Site Energy Saved: -3.65 Net Total Site Energy: -3.66 kBTU/sq .fl.
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Building Optimization Analysis
BEST OPTION:
WHY?
1. Window Optimization
Analysis:
9.1
By optimizing the windows, the Gross Total Site Energy was the highest out of all three schemes. I changed the windows glass to Clear Single Pane Glass with an SHGC of 0.64 This scheme was closest to my original scheme in regards to the energy cost as well as the Home Energy Rating. The other schemes did not do anything for a more efficient design and since the Window Optimization Scheme was the best but is very close to my original scheme, I will keep my original scheme.
Renewable Energy Analysis
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This design got to Zero Net Energy with 3W AC System which is approximate 10 panels for electricity. Utilizing the south and west facing roof is very efficient since the sun is hitting that side the most. As it can be seen in the model, The house, roof, and garage roof still have spots for extra PV panels. In this case we can place extra panels to store electricity on the site or even sell it to the electricity company in the area. An other option would be providing the spot to the neighbors who do not have enough roof space for panels and could rent them the space for placement.
Gross Total Site Energy: 11.96 kBTU/sq.ft (10% of Design 1) Electricity: 11.96 Fuel: 0.00 PV site: -13.15 SHW site: -3.62 Net Total Site Energy: -4.81
Carbon Neutral Energy Analysis
Water Heater was selected as electric (#6) from the beginning of this project.
Gross Total C02 Equivalent in lbs. 2,387.30 Electricity: 2,387.30 Fuel:O.OO PV Site Energy saved: -2,626.11 SHW Site Energy Saved: -722.17 Net Total Site Energy: -960.99 kBTU/sq.ft.
Analysis: A carbon neutral building is defined as one with significantly reduced energy consumption combined with the increased use of low carbon energy sources to meet the remaining demand. All of the design decisions I have chosen for my home has created a Zero Net Energy building. One that can produce as much energy as it uses. The solar panels, water heater, selection of flooring, HVAC units and architectural design has made it so my building won't be leaving a carbon footprint.
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Conculsion
Did We Reach A Zero Net Energy Home? My home was able to reach -5 Home Energy Rating. When considering strategies to reduce site EUI. I looked to the 2030 Palette for guidance. For my climate in Pasadena, California it suggested I look into South facing windows and an outdoor space while minimizing the amount of windows on the west facing side. This is what led me to design the home with a skylight and a patio. This patio will not only create common space between the inside and the outside but create a shaded space for my home. In addition, the thickness and the insulation of the walls is very important. Adding installation was helpful for keeping the temperature of the interior space comfortable so there is much less need for a heating-cooling system to be used. The best way to bring the fuel usage down to zero was using electrical utilities for the cooling-heating systems as well as changing the Water Heater system to full electric. I had some challenges when trying to get my home to Zero Net Energy before installing renewable energy. A big problem I had was with my floors which was becoming my biggest source of heat loss when looking at the Bar Chart. By changing my floor to Slab on Grade with Earth Under Slab, I was able to achieve the -5 Home Energy Rating. The climate in Pasadena, California does not have extreme winters but in the summer it can get pretty hot with the highest temperature being 103 degrees. I decided to use a Whole House Fan because it is the most energy efficient and cheapest option. All of my design decisions has allowed me to create my first Zero Net Energy home. The biggest question that was asked of us this semester was: "What role as architects do we want to play in the goal to Zero Net Energy?" I believe it is our job to create vernacular architecture that will be around longer than we do. It is our responsibility to leave the world as a better place than when we entered it. Architects will need to control this conversation so it goes towards the direction of a more green and efficient design plan. As architects, it is our role to avoid investment in companies that promote fossil fuels and to get rid of the buildings that are currently have high carbon energy use. Through design development, architects will be able to create not only a beautiful building but one that helps to protect our environment.
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