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Zero Energy Home Project

Team Tast-E

• Ben Wilson • Greg Crompton• Jeremy Ogorzalek • Brady Alford

10/19/2010

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Overview of the Project

The main goal of the project was to design a zero energy home to fit a family of four. A zero energy home (ZEH), can be defined as a building whose net energy consumption is zero or even less. The home had to be as environmentally friendly as possible while still remaining attractive to potential owners.

The most important features of the home were any that were on the south facing side of the house. Since our house is located in the northern hemisphere, the sun is most often shining from the south, and when designing a ZEH, the sun is your best friend. The southern side of our home is where the majority of windows and solar technologies, including solar panels and our solar water heater, are located so that they can utilize the sun’s energy to its full potential.

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General Info

Location Harrisburg

Electricity cost ($/kwh) 0.075

Conditioned floor area (sq.ft.) 1120

Number of bedrooms 3

Envelope Details

Wall construction

2x6 with R19 batt

& 1" foam

Ceiling Insulation R40

Window typeDouble low-

e

Upper floor ceiling area (sq.ft.) 1120

North wall area (gross) (sq.ft.) 400

East wall area (sq.ft.) 315

South wall area (sq.ft.) 400

West wall area (sq.ft.) 315

North window area (sq.ft.) 88.73

East window area (sq.ft.) 22.18

South window area (sq.ft.) 88.73

West window area (sq.ft.) 22.18

Air tightness Tight

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Research Summary

From looking at the many different designs that our fellow classmates came up with we learned that there were various other ways we could have completed the project. Some groups designed zero energy homes that were two stories. Some had garages. Some even deviated from the standard “box-shaped” house and created something a little more exciting. Most of these homes required many more solar panels and windows than we did due to our smaller size.

For instance, the recommended window space was twenty percent of the north and south walls. Our north and south walls are only 400 ft2. This means we only needed 80 ft2 whereas many of the other homes had to have much more because of their greater size.

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Envelope

Striving to be as energy efficient and environmentally friendly as possible, our team decided that a smaller home, and therefore a smaller envelope, would be the best choice. Our ZEH was one of the smallest ones out of the entire class, but we think it still allows for a four person family to live fairly comfortably.

The base part of our house is forty feet long, twenty-eight feet wide, and ten feet high. This equates to a volume of 11,200 ft3. There is also a rectangular section above this that is part of the open space of the house and has a volume of 1400 ft3. This brings the total envelope of our zero energy home to 12,600 ft3.

Our ceiling and walls have insulation values of R40 and R19 respectively, and out windows are double low-e. Our envelope is also as airtight as possible to avoid any unwanted air leakage or heat loss.

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Appliances• Refrigerator

– Frigidaire – 14.7 cu. Ft. Top-Mount

– Price: $382 – 355 Kwh/yr

• Television– 42” Panasonic

LCD HDTV– Price: $680 – 396 Kwh/yr

• Dishwasher• KitchenAid 24”

Single-Drawer• Price: $980.99• 174 Kwh/yr

• Clothes Washer• Bosch Nexxt 500

Series• Price: $699• 151 Kwh/yr

All of these appliances are more expensive then their alternatives, but make up for the difference over time due to decreased energy use

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HVACFor our ZEH, we wanted to have the most efficient, most compact

heating and air conditioning system possible. The system had to use high-efficiency electric heat in order to be as green as possible. With these specifications in mid, we settled on the Amana PTH153E50A.

The Amana PTH153E50A, is a Packaged Terminal Air Conditioner, similar to those found in hotel rooms. It is small, only 16” x 42”, and yet very efficient with a 9.8 EER rating.

Due to the very small and open nature of our home design, we decided that there was no need for any sort of ventilation system. Hot and cool air can easily circulate through every room.

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Solar TechnologiesFor our

photovoltaic system we chose to use Evergreen 200W Module ES-A-200 solar panels. These are each 200 watt systems, and with that in mind we decided to put sixteen of them on our home. At $580 each, they are a little expensive, but they are very efficient and look great.

For our solar water heating system we chose to purchase the Solahart Thermosiphon Roof-Mounted System. With a 150 liter storage tank this system insure that the owner of the house can take long showers without worry. Again, at $3,800, the system is pricey, but is expected to have a 15 year payback period.

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BehaviorEven with all the great energy saving and energy efficient

features of our home, the residents should still practice good green behavior. Some of the habits the owners should have include:

• Turning the lights off when not in use- Something we’ve all heard before

• Don’t waste water- Don’t let the sink run when not in use, don’t flush unnecessarily, etc…

• Utilize the windows- Open them on hot days, and make sure they’re closed

with the blinds open on cold days• Run appliances only at max capacity

- Only wash a full load of laundry or dishes

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Summer Solstice

All windows are shaded

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Winter Solstice

All windows receiving maximum sunlight

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South Side East Side

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North Side West Side

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Bedroom Master Bedroom Bedroom

Bathroom

Bathroom

Kitchen

Living Area

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Summary of Design

Some of the most important aspects of our design are the size and positioning of the windows as well as the photovoltaic system. The windows had to be large enough to collect enough sunlight in the winter to make a difference in heat, and the roof overhang had to be long enough to block the sunlight in the summer. We needed to have enough solar panels to collect enough solar energy to power the house, but we also needed to make it look good.

One of the greatest challenges we encountered while designing our home was the allocation of space inside the house to different rooms. Another challenge was simply researching and deciding which products to use for our appliances, photovoltaic system, and solar water heater. Balancing price with efficiency turned out to be much harder than expected.

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Favorite Features

Jeremy – “I really like our strip of windows above the roof on the south side of the house. I think it’s a creative way to use more sunlight, and looks great.”

Greg – “I like the interior design of our zero energy home. It’s a house that I wouldn’t mind living in.”

Brady – “I thought our positioning of solar panels and the solar water heater was particularly attractive to potential buyers.”

Ben – “The overall design of our home is not extremely exciting, seeing as how it does look like a box. But I think that adds a sense of modesty and conservation to the house, which is what this project is all about.”

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Lessons LearnedLess is more

The smaller a house is, the less energy it takes to heat and cool the house. Also, the shorter showers are and the less time appliances are being used, the more energy is saved.

The sun is your best friend

The energy of the sun can be used in more than one way to our advantage. Solar panels can be used to turn solar energy into electricity. A solar water heater can eliminate the need for a water heater that uses excessive amounts of energy. Windows can let in sunlight during cold seasons to heat the house. Clothes can be hung outside to dry, eliminating the need to use a clothes dryer every time.

Think about the future

Don’t just act in a way that will benefit you now. Spending a little more money on an energy efficient appliance may end up saving you a lot of money in the long run.

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Team Tast-E