ARCHITECTURE 215
DESIGN FOR THERMAL - FINAL Z.N.E PROJECT
HOLLOMAN A.F.B - Z.N.E 3 UNIT BARRACKS (18 occupants) Standard
BY: CHRISTIAN LANCE S. RELLEVE (2019) University of Southern California
Z.N.E
Site Context and Section Cut PV panels
DET. 3 P.9
Project Site: Holloman Air Force Base, New Mexico Coordinates: 32°50’02.2”N 106°04’53.0”W
high termal mass floor
water collector system
Final Design Section
The goal of this single unit barrack design is to have it modulatable and connect to new unit if needed. For this project, 3 units will be analyzed interconnectably.
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Schematic Design
Due to the military’s issue budget issue regarding addition, retrofit and maintenance of infrastructures, this design’s impetus is to create a new barrack typology that will produce more electricity, therefore lowering the operating cost. In addition, to utilize systems such as: Rain collector systems, misters, thermal mass utilization, and minisplit systems with radiant heaters. Each module is 307 SF = Totaling 921 SF for 3 units interconnected.
Project Plan and Elevation
NORTH IS UP
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Project 3D model and details Exploded Axon - South East
Solar Hot Water: To be transfered to sink and bathroom
Array of PV panels: battery located underground Gutter to Water Reservoir Mister and humidifier
Thermal Mass flooring (Concrete)
6 Bunk beds: vertically place for heat efficiency
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Water Reservoir system: for misters and backup water
CLIMATE CONSULTANT - 6.0 The project goal to reach ZNE for my attachable barrack system first needed parameters: These parameters are met with the following: 1.) Choosing a site — In this case, Holloman AFB in New Mexico 2.) Using Climate Consultant’s Design Guide 3.) Using 2030 Pallette to guide schematic form that is relevant to site After creating a preliminary schematic design (P.2) The design now goes through thorough data analysis of Climate Consultant.In addition, we will be using programs such as: HEED (High Energy Efficiency Design) and OPAQUE.
DESIGN GUIDELINES by 2030 Pallette: (—) Adopted in design
42: On hot days ceiling fans or indoor air motion can make it seem cooler by 5 degrees. Less air cond. needed 60: Earth sheltering, occupied basements, or earth tubes reduce heat loads. 45: Flat Roofs work well in hot dry climates 20: Provide double pane high performance glazing on west, north, and east. But clear on south for maximum passive solar gain. 19: For passive solar heating face most of the glass area south to maximize winter sun exposure, but design overhangs to fully shade in summer. 61: Traditional passive homes in temperate climates used high mass construction with small recessed shaded openings, operable for night ventilation to cool mass 66: Traditional passive homes in hot windy dry climates used enclosed well shaded courtyards. 29: Humidify hot dry air before it enters the building from enclosed outdoor spaces with misters, etc. 37: Window overhangs (designed for this latitude) or operable sunshades can reuce air noditioning. 50: An evaporative cooler and providde enough cooling capacity. 47: Use open plan interiors to promote natural cross ventilation, or louvered doors. 43: Use light colored building materials and cool roofs. 35: Good natural ventilation can reduce or eliminate air conditioning in warm weather. 54: Provide enough north glazing to balance daylighting and allow cross ventilation. 11: Heat gain from lights, people, and equipment. 37: Window overhangs and operable sunshades. 3: Lower the indoor comfort temperature at night to reduce heating energy consumption. 32: Minimize or eliminate west facing glazing to reduce summer and fall afternoon heat gain. 39: A whole-house fan or natural ventilation can store nighttime “coolth” high mass interior suerfaces. 41: The best high mass walls use exterior insulation (like EIFS foam) and expose the mass on the interior.
Comfort Zone: 69F degrees to 75F degrees Hottest Month: July Average High: 94F degrees Average Low: 64F degrees Coldest Month: January Average High: 54 degrees Average Low: 29 degrees
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CLIMATE CONSULTANT - 6.0
June 21 to December 21
December 21 to June 21
After analyzing specific design parameters (shown on previous page), the sun shading chart is utilized. Looking at both charts, 45 degree is ideal. Due to the site context of a desert region, more overhang is better as this outweighs the cons. For June 21 to December 21, the overhang angle was chosen in which can still may receive some heat from the west. Due to the design of having an interconnecting aspects of units, the West will not be an issue. Additionally, heat requirements will be integrated in the modulated units via: (The 45 degree implementation section drawing is at page 2) 1.) thermal high mass slab located at the south face. This will creep in heat and will be emitted during night flushing. 2.) Since each unit can house 6 soldiers, each individual naturally emits body heat of 300 BTU/Hr (Equating to 1.8 KBTU/Hr at night. The placement of bunk beds as vertical will help as heat naturally rises. 3.) An optional radiant heating system located at the East Wall (Since East will also be blocked out due to the modulation of units). The heating system 6 is strategically placed for night comfort.
Shading Optimization
DECEMBER 21 @ 1200 DURING COLD PERIODS, PARTIAL SUN PENETRATION WAS EMPHASIZED. DUE TO THE DRASTIC OVERHANG, THE EMPHASIS HERE IS THE THERMAL FLOORING THAT WILL TRANSFER HEAT VIA CONDUCTION CREEPING IN THE INTERIOR SPACE AT NIGHT. JUNE 21 @ 1200 DURING HOT PERIODS, THE FAR OVERHANG OF THE SOUTH BECOMES ADVANTAGEOUS, IN ADDITION, THE HIGH ROOFING WILL PREVENT HEAT ACCUMULATION AT THE LIVING SPACE, INSTEAD, HEAT WILL ACCUMULATE AT THE SHED ROOF. THE NORTH SIDE HAVE OPERABLE WINDOW OPENINGS. (HOPPER WINDOW) JUNE 21 @ 1500 THE WEST OPENING WILL ONLY RECEIVE HEAT FROM THE MODULE THAT IS LOCATED AT THE END OF THE CHAIN. ALL ADJACENT UNITS WILL NOT RECEIVE THE WEST FACING HEAT. 7
Shading Optimization The south wall facade was optimized with its existing design overhang, but the SHGC of the window have been optimized to have the best SHGC factor. The 0.50 SHGC Glass window performed better in which was the closes at creating the “Saddle shape�. Though the KBTU/Hr may still be high, at least it can be utilized during the cold period of September to February. A way to utilize this added KBTU is to retain it using a higher thermal mass flooring, and lagging it until night-flush period. The high KBTU/Hr can also be mitigated by the cross ventilation design to flush out the accumulating heat.
0.50 SHGC Glass Window (South Wall)
0.16 SHGC Glass Window (South Wall)
The West Wall can utilize the low SHGC window due to the high amount of heat from the west face. A high thermal mass for the West face may be beneficial. Note: that the west face has a single window, but if all unit modulation connects, the unit itself will be blocking the west fall of the neighboring units. (Example on previous page of June 21 @ 1700)
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0.50 SHGC Glass Window (West Wall)
0.16 SHGC Glass Window (West Wall)
Building Envelope Optimization The walls need to be as efficient as possible to reduce heat from escaping during night hours. The time lag and decrement factor play an important role in this analysis. Stats: Wall Thickness: 9.5 inches R-Value: 20.04 U-Value: 0.04 Decrement Factor: 0.74 Time Lag: -4.81
Wall assembly 1 (10” thick)
STANDARD WALL
CUSTOM WALL FOR PROJECT SPECIFIC
- 2x6 studs @ 24” O.C. - 1” Insulation Board
(THICKENED THE INSULATION BOARD BY x3)
comfort
comfort
The walls need to be as efficient as possible to reduce heat from escaping during night hours. The time lag and decrement factor play an important role in this analysis. The exterior insulation board have been trippled to delay heat entrance, while containing heat and delaying heat escape. Stats: Wall Thickness: 11.5 inches R-Value: 32.66 U-Value: 0.031 Decrement Factor: 0.69 Time Lag: -6.22
Wall assembly 2 (12” thick)
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Building Envelope Optimization
Wall Assembly 2 of South Wall
Wall Assembly 1 of South Wall
BETTER
OK
This wall is efficient, but note the thickness of 11.5 inches.
detail of wall assmebly incorporated to project: (Detail __)
Energy Cost of Wall Assembly 2: Energy Cost of Wall Assembly 1: GROSS ELECTRIC VALUE: $4,168 AIR CONDITIONER: $416.51 FANS-BLOWER: $502.90 LIGHTS: $268.93 EQUIPMENTS AND APPLIANCES: $331.74 ELECTRIC HEAT OR HEAT PUMP: $2,648.04
GROSS ELECTRIC VALUE: $3,828.40 AIR CONDITIONER: $379.21 FANS-BLOWER: $461.77 LIGHTS: $265.15 EQUIPMENTS AND APPLIANCES: $327.07 ELECTRIC HEAT OR HEAT PUMP: $2,395.04
NET ELECTRICITY COST: $4,168
NET ELECTRICITY COST: $3,828
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SAVING OF $340
Wall Assembly 2 of South Wall
Wall Assembly 1 of South Wall
Creating a high decrement factor and time lag help significantly: The decrement factor, which is a coefficient from 0 to 1, emphasizes the heat transfer dissipation. A 0 would mean the wall mass would be very high in which heat will not reach from the opposite side from which heat entered. While a 1 in coefficient is a complete allowance of heat within the space. A decrement factor of reaching 0.5 is ideal due to the outdoor swing - indoor swing of temperature differences. The median must be reached. Finally, time lag is the number of hours before the heat reaches the opposide side from which heat entered. In this case, of wall assembly 2, which has a time lag of 6.22 will take 6 hours an 13 minutes for the heat to reach internally. In this case, the south wall of having this time lag will start having the heat come in at around the time of: 2200 from west facing. From the data shown, wall assmebly 2 have lowered the Averate KBTU/Hr lose. from wall assmebly 1. This would make the heat creep be contained within the space for the prolonged period of its need (during night periods). As morning enters, the heat can be flushed out using cross ventilation technique (bar shaped floor plan) and opening upper windows by the high pitch shed roof located at the north side — while heat can be absorbed by the wall assembly again creating a cheating and cooling cycle that is beneficial.
Natural Ventilation and Cooling Analysis WIND WHEEL FOR JANUARY: Having the climate consultant 2030 pallette strategy utilized from the very begining of the design process. The cold winds are coming almost at every face. We will use: - Operable windows (24 x 72)
double hopper
Natural Ventilation only plays about 7.9% of the suggested design strategy. Though, we will utilize the wind wheel to tweak the building overall footprint.
WIND WHEEL FOR JULY: Having the climate consultant 2030 pallette strategy utilized from the very begining of the design process. We can utilize the initial design further by preventing hot winds from the south side: We will use: - Misters at the south overhang - Operable windows
mister of south overhang: (Detail 1 OF P3)
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Natural Ventilation and Cooling Analysis
Indoor temperature versus outdoor temperature of slab on grade flooring. The chart is within the week of the hottest period. No systems for cooling implemented.
Energy Cost of Changing to Slab on Grade (Earth Under) : GROSS ELECTRIC VALUE: $3,178.34 AIR CONDITIONER: $193.9 FANS-BLOWER: $312.47 LIGHTS: $257.74 EQUIPMENTS AND APPLIANCES: $317.94 ELECTRIC HEAT OR HEAT PUMP: $2,097.10 NET ELECTRICITY COST: $3,178.34
SAVING OF $649.66
Indoor temperature with Slab on Grade flooring. No systems for cooling implemented
Indoor temperature with raised wood flooring. No systems for cooling implemented
INDOOR AIR VELOCITY FOR COOLING: - NO FAN NATURAL VENTILATION: - WINDOWS AND DOORS ARE MANUALL OPENED IF COOLING IS NEEDED
comfort level achieved and complies with ASHRAE
FAN FORCED VENTILATION: - NO FANS FOR COMFORTCOOLING Suprisingly, the initial design have reached comfort level for the interior. Therefore, adding a fan forced ventilation for the interior is not needed (optional). Since we are trying to reach Zero Net Energy, the fan will be omitted as the case of achieving a successful passive design is the primary impetus. But according to the image of the upper right data chart, switching to an on-grade slab flooring is better than using a raised wood flooring system. Therefore for the initial design, we will incorporate this.
6 units with berm added with on grade slab flooring l---------------------------------------------------------------------->
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site: http://comfort.cbe.berkeley.edu
Passive Heating and Mechanical System Sizing Analysis
1.) Initial infiltration envelope: Very Poorly sealed building envelope
3.) Initial infiltration envelope: Very Poorly sealed building envelope
2.) Initial infiltration envelope: Passive house design - Extremely tight air sealing
4.) Initial infiltration envelope: Passive house design - Extremely tight air sealing
Energy Cost of Changing to Extremely Tight Air Seal : GROSS ELECTRIC VALUE: $2,153.34 AIR CONDITIONER: $125.91 FANS-BLOWER: $219.31 LIGHTS: $238.22 EQUIPMENTS AND APPLIANCES: $293.81 ELECTRIC HEAT OR HEAT PUMP: $1,276.04 NET ELECTRICITY COST: $2,153.34
SAVING OF $1024.97
Initially, having the building envelope as a “Very poorly sealed building” made infiltration prominent towards heat loss, especially from ventilation. (img 1 + 3) This is not ideal during night periods due to the heat loss that may pertain and collected. Higher negative number means higher heat loss. Switching to “Extremely tight air sealing” have made the difference of: (Img 1 + 2) Ventilation 1 (-9,557) - Ventilation 2 (-1,961) = 7596 BTU/Hr difference. Switching to “Extremely tight air sealing” have made the difference of: (Img 3 + 4) Ventilation 1 (1,162) - Ventilation 2 (367) = 795 Component heat loss and gain. This creates an extremely efficient design in terms of retaining heat from ventilation.
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Cooling system sizing analysis and Mechanical Equipment Sizing
“Extremely Tight Air Sealing” The air conditioning system (Mini-split) can work less
“Very poorly sealed building” The air conditioning system (Mini-split) have to work more.
The flatter the bar, the more efficient the design systems are. The passive design will make mini-split be used less regardless and radiant heating system by the East wall. Though, the option to have these systems makes the design versatile and adaptable. Having an extremely tight air sealing envelope versus a very poorly sealed building can significantly change heat loss and gain, therefore saving or spending more in energy cost.
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See Detail (2 PAGE 2) for integration of mini-split and radiant heating system
Cooling system sizing analysis and Mechanical Equipment Sizing Switching from On-grade slab flooring to wood-flooring with vented flooring have increased the net dollar cost of $579. It is ideal to puruse the on-grade slab flooring for this project instead.
CHANGED TO ON-GRADE SLAB Energy Cost of Changing to Wood floor and adding fans : GROSS ELECTRIC VALUE: $2,732.58 AIR CONDITIONER: $282.18 FANS-BLOWER: $354.01 LIGHTS: $248.15 EQUIPMENTS AND APPLIANCES: $306.10 ELECTRIC HEAT OR HEAT PUMP: $1,542.15 NET ELECTRICITY COST: $2,732.58
ADDITIONAL COST OF $579.24
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Building Optimzation analysis
Base Option: 1 (Standard)
Base Option: 2 (Medium)
Base Option: 3
This is the data in where we started from the design process.
This is the data in where we started from the design process.
This is the data in where we started from the design process.
- Window: High SHGC of south window - Very poor sealing - New 2x12 wall assembly (Custom) - Slab on grade flooring - Energy Star Heat Pump (pragmatic) Net cost: Net EUI: 47 kBTU/SF per year
- Window: High SHGC of south window - Air-tight sealing envelope - Standard 2x12 wall assembly (custom) - Slab on grade flooring - Energy Star Heat Pump (pragmatic) Net cost: Net EUI: 42 kBTU/SF per year
- Window: Low SHGC of south window - Very poor sealing - Standard 2x6 wall assembly - Raised wood flooring system - Energy Star Heat Pump (pragmatic) Net cost: 16 Net EUI: 55 kBTU/SF per year
Renewables 7kWH/ PV and SDHW added
Finally, adding Photovoltaic Solar Electric Systems and Solar Domestic Hot Water is the final step in reaching Zero Net Energy. Based on the analysis: 6kW AC Systems w/ 30 Panels is enough to power 3 units and the minimum to reach Zero Net Energy. Dividing 30 panels by 3 (PV per unit). (540 SF of roof area) You will only need 10 panels per unit. (ZNE Achieved) Site Energy Use: -328 kWH / year (for all 3 units) Site EUI: -1 kBTU/ sq ft. per year Cost: -$930.67 (per year surplus)
6kWH/ PV and SDHW added (Minimum) to reach ZNE
Furthermore: with a 7kW AC Systems w/ 35 Panels, it is enough to bring back -$1427.80 of energy cost back to the grid. 35 divided by 3, each unit will only need 12 panels. (630 SF of roof area) (ZNE Achieved + surplus back to the grid) Site Energy Use: -2430 kWH/year (for all 3 units) Site EUI: -6 kBTU/ sq ft. per year Cost: -$1427.80 (per year surplus)
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Renewables Energy Cost of adding 7 kW AC Sys. with 35 Panels + Solar Water Heating System: GROSS ELECTRIC VALUE: $2,153.06 AIR CONDITIONER: $125.58 FANS-BLOWER: $219.07 LIGHTS: $238.48 EQUIPMENTS AND APPLIANCES: $293.85 ELECTRIC HEAT OR HEAT PUMP: $1,276.08 +PV GENERATED ON SITE: -$3580.45
NET ELECTRICITY COST: -$1427.8
Energy Cost of adding twice the PV + Solar Water Heating System: (Design to utilize MAX roof PV panel SF placement) 72 Panels total for 3 Units. (24 panels per unit)
NET ELECTRICITY COST: -$3000 +/-
Each Single Unit will provide -$1000 of surplus with max SF PV usage from its initial design — with 24 Panels
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Carbon Neutral Energy Analysis
Before - with no optimizations (Starting)
After - with optimizations and efficient systems added
Differences:
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Total Electricity Purchased (Net): 21,164 Cost of Electricity Purchased Net: 5595.5 EUI Net Site: 61.66 Net Carbon Dioxed Produced Site (pounds): 38,960.29 EUI Net Source: 174.17 Net Carbon Dioxide Produced Source: 115,218.74
Conclusions and Analysis
CONCLUSION: Designing a ZNE building starts with a framework of parameters of what is needed to achieve — for this case the endeavor to reach ZNE (Zerno Net Energy) is the objective. The methodology of using Climate Consultant’s design strategies is a great way to start the project, as these analysis will dictate the best design approach of creating an efficient form. As we progress, the utilization of tools such as “HEED” and “Opaque” becomes vital in terms of keeping track of energy costs and temperature analysis to stay within “comfortable range”, Energy use intensity, Floor and wall systems, ventilation system, and orientation. Finally, the application of systems (PV and HVAC systems) may or may not reach ZNE, but in this case, we have reached ZNE + a Home Energy Rating of 5 stars.
DESIGN
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FRONT WALL REMOVED
DISSECTED
Z.N.E. NEW BARRACK TYPOLOGY FOR HOLLOMAN A.F.B. IN MEXICO