Zero Energy Home Project

Transcription

1 Zero Energy Home Project October 14, 2016 Engineering Design 100 Section 020 Team CNSS & Associates: Brianna Cimino Matthew Norris Benjamin Smith Alexus Steininger Submitted to: Dr. Bharti

2 Abstract: The need for efficient and responsible energy usage coupled with long term savings has driven the creation of a market for zero energy homes. Through analysis of the successes and failures of past and existing zero energy homes, a new design was developed that also drew upon the addition of recent technological advances. A scaled-down model of the home was subjected to weather experimentation to determine the feasibility of a full size version. The project and results were then analyzed to draw conclusions about the offered design.

3 Introduction: Team CNSS consists of four student engineers tasked with designing and modeling a net zero energy home for a family of four living in State College, Pennsylvania. Net zero energy homes produce as much or more energy than they consume through the use of renewable energy sources, including passive solar, active solar, geothermal, and wind. This required learning about renewable energy in class and independent research completed outside of the classroom in order to develop a strategy for meeting our customer needs (more on that in the next section) while remaining within the constraints of the project. Customer Needs and Target Specifications: The first step undertaken in the design process was to lay out all the essential functions which the house had to fulfill to be a success. This influenced all later steps, including where research was focused and the basis of our concepts. The customer needs were updated throughout the process as new ideas were happened upon and the capabilities of the house became clearer. Overall, the needs and target specifications selected were: Needs Produce enough energy to meet all needs Specification - Annual KWH from solar panels greater than ~5500 kwh/year Maximize solar energy collection - High efficiency solar cells (HIT N330) Solar panels need to be cost efficient/affordable Should have enough accommodations for two kids and two parents - High efficiency solar panel at high initial cost to save money over time, and appeal to high budget customers - 1 master bedroom - 1 kids room with dividing curtain

4 Bathrooms adequate to support utility/sanitary and privacy needs of all occupants - Larger bathroom top floor - Smaller bathroom ground floor Minimize need for powered HVAC - Open floor plan hybridized with compartmentalization to control airflow/flow of temperature around house - Heat mass walls - Passive solar heat collection through large south windows - All windows (including large south facing banks) openable for airflow increase As many tasks as possible done without power - Clothesline for drying clothes - HVAC (see above) - House-wide ventilation - Open floor plan - Openable windows - Floor plan designed to allow hot to flow upwards through staircase to balcony window Additional active non-grid HVAC - Closed loop geothermal heat/cool piping grid through floors Appeal to customers with larger budgets - Larger floor plan - Large balcony setup - Highly efficient solar cells (despite cost increase)

5 External Research: Below are three examples of Zero Energy Homes found in the United States, specifically in a climate similar to that of State College, Pennsylvania. Relevant information to the project was gathered about them, such as square footage, number of floors and number of bedrooms, as well as information regarding the heating and cooling systems and the R-value - which is the capacity of an insulating material to resist heat flow. The higher the R-value, the better. When it comes to solar energy, it is important to note the difference between passive and active solar. Passive solar refers to the use of the sun's energy for the heating and cooling of living spaces. On the other hand, active solar uses mechanical and electrical equipment to enhance the conversion of solar energy to heat and electric power. Solar panels are an example of active solar. The first home, Green Acres #20, is located in New Paltz, New York. It is fairly big in size at 4,454 square feet over a total of three floors. It runs on electricity and has a great R-value based on the location of the home. The ambitious size of its photovoltaic system and cost factored into our final design. Location (city, state) House size (floor area in square feet) Number of floors URL of web site where info is found New Paltz, New York 4,454 sq ft 3 + basement 27/Greenhill_20_26_ _DOE_ZE

6 Number of occupants 5 Number of bedrooms 4 R-HIA_casestudy_PNNL pdf Type of heating system (forced air, hydronic, radiant floor, heat pump, etc. Main heating fuel (electricity, natural gas, wood, oil, etc.) Size of photovoltaic system (kilowatts) Solar water heater (yes or no) Ground Source Heat Pump Electricity 11.5 kw No R-value of wall insulation 22 R-value of ceiling insulation 63 Ventilation air heat recovery (yes or no) No, an energy recovery ventilator is used instead to conserve humidity. Predicted or measured annual energy use Gigajoules

7 The second home, O Neil ZEH, located in Perkiomenville, Pennsylvania is a two story home with a 2016 square foot floor plan. Unlike the first home, the O Neil ZEH runs on geothermal energy. The final design of Team CNSS & Associates adopted several features of this home, such as partial inspiration from the roof, floor area and number of floors, and heating system. However, its occupancy was too low and the photovoltaic system did not fit with our targets. Location (city, state) House size (floor area in square feet) Perkiomenville, PA 2016 sq ft Number of floors 2 URL of web site where info is found tails.cfm?who=296&feature=all&action=sh owdetails&query=multiquery Number of occupants 1 Number of bedrooms 2 Type of heating system (forced air, hydronic, radiant floor, heat pump, etc. Main heating fuel (electricity, natural gas, wood, oil, etc.) Size of photovoltaic system (kilowatts) Radiant floor and heat pump Geothermal 5.25kW

8 Ventilation air heat recovery (yes or no) No R-value of wall insulation R-23 R-value of ceiling insulation R-45 Ventilation air heat recovery (yes or no) Yes Predicted or measured annual energy use Net: -400 kwh Any other pertinent info Trees removed to make room for the site were used in the house for various things. The third home, located in Lusby, Maryland is a two story home just over 2,000 square feet. The home runs on a forced air heat pump, a fireplace and Municiple Energy. This home is the closest in floor area to the final design, and the rooftop balcony was influenced by the house. Location (city, state) Lusby, Maryland House size (floor area in square feet) 2,212 sq ft Number of floors 2 URL of web site where info is found /view/united_states_maryland_lusby_2065 7_19352 Number of occupants 4

9 Number of bedrooms 3 Type of heating system (forced air, hydronic, radiant floor, heat pump, etc. Main heating fuel (electricity, natural gas, wood, oil, etc.) Size of photovoltaic system (kilowatts) Solar water heater (yes or no) R-value of wall insulation R-value of ceiling insulation Ventilation air heat recovery (yes or no) Predicted or measured annual energy use Any other pertinent info fireplace, forced air heat pump, Municipal Energy NA solar passive NA NA part of cooling and heating system NA well water, septic system, Passive Solar-Trombe Walls, enclosed sun porch Morning Star: In addition to our online research of ZEH our team also visited the on-campus facility, the Morning Star home. One of the features in the Morning Star home that we would like to replicate in our home design is the mobile space division. This allows not only the option of privacy but for an open concept if friends and/or family come over.

10 Concept Generation/Selection: (A few early concepts. The middle concept is from early in the series that eventually led to the final design.) Concept #1 Concept #2 Concept #3 Criteria Weight Rating Weighted Score Rating Weighted Score Rating Weighted Score Energy Production Aesthetics/ Comfort 50% % Ease of Build 15% Space efficiency 15% Sum 100% Team CNNS & Associates explored several house concepts from the outset, but a series of designs based upon the very first concept were prominent. Although each iteration added new variations to the frame, this series of designs primarily centered around a very large ground floor in a rectangular shape, with a division of kitchen and living room to the south, and bedrooms and bathrooms to the north. In between ran a long hallway room to promote airflow. This eventually evolved into the final design of the team s net zero energy home, which was a variation where a second floor was developed. This evolution occurred as a result of the need to procure more floorspace for the high-end consumer, among other factors. By shifting the bedrooms and bathrooms vertically upwards, the ground floor gained space for a few more traditional fixtures in medium to large scale homes, such as generic floorspace and a dedicated dining area. The living room and kitchen were also both able to expand, and a bathroom was added to the first floor so the family no longer had to share their personal bathroom

11 with guests. The second floor also added new possibilities for unpowered HVAC, adding the dimension of elevation to control of household airflow. However, the second floor made previous plans for one or two thermal chimneys to be discarded, as they were far too complicated to construct on the scaled down model. If the design was going to be constructed with better materials at a larger size, the chimney would be reimplemented. Design/Energy Analysis: Using the ZEH Calculator excel spreadsheet provided by instructor Dr. Bharti, the designed home would consume 5,340 kwh/year (recommended PV system size of 6.83 kw), and cost $292,964. This is well within acceptable limits, as at current specs the roof could be configured to host a PV system of up to 10 kw, and we are selling to high budget customers anyways. The results of the in-class testing reveal mostly positive results for the design. During the daytime trial, the temperature rose by 5 degrees Celsius, while it fell 4 degrees Celsius during the night trial. An analysis of this finds a few likely reasons for the difference in gain vs. loss. Most significantly, the windows of the building were inoperable due to construction constraints. Furthermore, the sensor used in testing was placed in one of the hottest rooms of the house, but also one of the most sheltered from the night time fan. Furthermore, this design started at the lowest temperature of any design tested, so the diminishing returns property that thermodynamics dictates to space heating would imply that the design would have had a lower change in temperature if it had started at the same temperature as the majority of the other designs did. Overall however, the changes in temperature were well within success parameters, and still strong scores. Even better relative performance would doubtless be obtained with a full-scale model using the real material. Saran wrap and foam core are poor substitutes for triple paned glass and insulating concrete form.

12 Three Dimensional Model: *Note doors are not shown for sake of visibility Dimetric View Front of House Back of House:

13 Top Floor Layout

14 Bottom Floor Layout: Model Description: The final designed house is two stories tall with 2 bedrooms and 1 bathroom. The house features floor to ceiling windows along the south front of the parlor and hallway on the top floor. A large balcony on the second floor provides an excellent socializing location during the non-winter months. The first floor of the home incorporates and open space layout with the kitchen flowing seamlessly into the dining and living space. The parlor includes an area for growing either herbs and vegetables or flowers, taking use of the vast amounts of sunlight provided by the south facing floor to ceiling windows The floor and walls of the parlor are also thermal mass to store heat from the sunlight to keep the house warm at night time. The second floor includes a master bedroom, full bathroom and a large children s bedroom for two children to share. The roof is covered in photovoltaic cells to provide power to the home and charge batteries during the day to power the home at night. Conclusions: The design performed extremely satisfactorily, and the assigned task completed. Team CNSS & Associates net zero energy home met all customer needs and target specifications, and despite construction flaws in the model it still returned strong results. While the open floor plan, windows, choice of solar panels, layout, and geothermal radiant heating all remain very strong properties of the house, there is of course room

15 for improvement. The house would benefit from additional non-powered cooling HVAC features, and more light entering the house on the West and North sides solely for interior lighting purposes (as passive solar requirements are already met). Additionally, features such as sustainable food producing garden and thermal chimney were concepts that did not make it into the final design, but would be welcome for reimplementation in a redesign of the house. In summary, the Team s design is a strong base, and could become even stronger with refinement. References: "Lusby, Maryland, United States - Green Home Natural Home." Greens Homes for Sale. N.p., n.d. Web. 13 Oct _19352 "O'Neil Zero Energy Home." Homes Across America. N.p., n.d. Web. 14 Oct "PVWatts Calculator." PVWatts Calculator. National Renewable Energy Laboratory, n.d. Web. 01 Oct "Technical Pages." U.S. Department of Energy Recommended Total R-Values. N.p., Web. 14 Oct < Contact the Authors: Brianna Cimino: blc5443@psu.edu Matthew Norris: mjn5380@psu.edu Ben Smith: bqs5462@psu.edu Alexus Steininger: ajs7146@psu.edu