You Can Go a Long Way Toward a Zero Energy Home

We need to face it... changing a few light bulbs ain't gonna do it. Reducing your energy use a few percent still means you are generating a lot of damage to the environment.

We need to start thinking in terms of moving toward ZERO impact. We don't have the luxury of risking "what if we make a few little changes in our lifestyle", and hope that's enough. Six billion people got us into the situation were in. Six billion people cutting their energy use a few percent isn't enough. What we do or fail to do will create the quality of life for children in future generations. The stakes are too high to take the situation lightly. We need BIG lifestyle changes.

It's possible to make a home that uses no energy other than what it cleanly makes from the sun or wind, or energy exchanged with the ground. True, it's not cheap. But what makes sense is to take a look at the technologies available and incorporate those that are reasonably achievable now. Then, each year, do a reassessment. The field of energy efficiency is growing fast. There will surely be lots of new technologies and products coming along in the next few years. And the price of many energy savers that you can't afford now should come down in the future. Over the course of the next five years, you should be able to get much closer to a zero energy home (ZEH).

This shows how important a single item can be, such as your refrigerator or water heater. By concentrating on key areas, it's possible to greatly reduce the energy use in a home.

Here's what a house that has greatly reduced energy use might look like:

 

Clothes washer

Asko W6022 clothes washer using cold water for most loads. The Asko is a phenomenal unit, using only 100 kWh per year. Some washers use over 400 kWh per year, according to the ENERGY STAR program. about $1200

 

Dishwasher

Asko, Bosch and Fisher & Paykel all have units that are ENERGY STAR rated at around 190 kWh per year. This compares to 531 kWh/year for the least efficient model currently made.


Refrigerator

Sun Frost refrigerator. These use between 171-254 kWh/year, depending on the size, compared to over 700 kWh/year for the less efficient units currently on the market. Older refrigerators use as much as almost 2,000 kWh per year! And a unit that's using lots of energy is also heating up your kitchen, increasing the load on the cooling system (and making your home less comfortable).

sunfrost.com

 

Home Cooling

A central air condition with a seasonal efficiency rating (SEER) of 20 or higher is used. Models include Carrier Infinity and Lennox Signature Collection XC21. Additionally, south facing windows would have window tinting designed to reduce heat gain in the home.  Either window awnings are used or shade trees are planted to minimize direct sunlight coming through the windows during the summer months. Ceiling fans are used in most rooms. A programmable thermostat is used. Warm Window Insulated Shades (or similar insulated shades with a good air seal) are used. These reduce heat loss through windows making any room comfortable all year long, as well as reduce outside noise.

ceiling fans ~$100-400 per fan

programmable thermostat: $30-100

window tinting: ~$100-200 gilafilms.com

Warm Window Insulated Shade System how they work

 

Roof

The roof is light in color, to reduce heat build up in the house during the summer. A radiant barrier is used in the attic to reduce heat build up in the attic.

Radiant Guard $100-200 (for materials)

 

Computer(s)

The Everex StepNote NC1501 is claimed to be most energy efficient notebook PC in the world. It uses only 12 watts of peak power. A desktop computer and monitor can typically use between 140-230 watts. Additionally, a TV tuner card can be plugged into the USB port. This makes an extremely efficient TV set. Hauppauge even makes a TV tuner for computers with remote control.

 

TVs

TV size is limited to 20-26 inches. A typical 20 flat screen, such as from Sharp, uses about 60 watts. A 26 inch uses 120 watts. The large screen sets use as much as 610 watts, over 10 times more than a 20 inch model.

 

Hot water

An evacuated tube water heating system is used. These work better on cloudy days than older types. This is augmented by a tankless, on demand water heater. Additionally, 1.5 gallon per minute (GPM) shower heads, such as the Jet-Stream Showerhead, are used. Faucet aerators are used on sink faucets. Hot water pipes are insulated.

shower head: ~$30 each

pipe insulation ~$50-100 (materials)

 

Lighting

A blend of lighting is used. Solar tubes are used to "pipe" sunlight into the house. These make a cheerier, more pleasant room. LED lighting is used in the most frequently used locations. LED lights are more efficient than fluorescents and generate almost no heat, reducing cooling costs. Compact fluorescent bulbs are used in areas where lights aren't on a lot.

C. Crane's LED lights

solatube.com

HUVCO tubular skylight

HUVCO tubular skylight

A solar tube, shown in these before and after images, give free natural light with no energy use. Different diameter tubes are available. This one is from Solatube.

HUVCO tubular skylight

 

Heating

Geothermal heat can pay for itself in a few years. If it's used, it is usually used to heat the homes water, too. Unfortunately, these systems haven't caught on well, despite their great merits. An alternative is the use of Solarsheat. These are panels on the roof or outside of walls. They capture heat from the sun and bring it into the house with small fans powered by solar cells. Solarsheats can either be used individually, to heat one room, or they may be used to distribute heated air to the entire home. Panels can be mounted on the roof, with the heated air ducted to the cool air intake of the conventional furnace. In a 2,000 square foot house, typically either four or five SolarSheat panels would be used. (pdf graphic of the SolarSheat Furnace Retrofit Pak) Additionally, specific rooms can be heated with radiant heat either under carpet or under the wood floors. This lets the home owner keep one room, such as a bedroom, comfortable, while the rest of the house is cooler.

more about Solarsheat

Geothermal Resources Council

 

Electric power

 
image credit: SCHOTT AG

Solar photovoltaic (PV) panels are used to generate electricity. Interestingly, all the above technologies probably give a greater return on the investment than solar panels. So it makes sense to reduce the demand for electricity as much as possible, first. Then use a PV system sized to meet the demand of the home.

 

 

 

For an existing home, there's a lot you can do to reduce it's environmental impact. You can use these technologies to get closer to having a zero energy home. Just think how much you can increase your home's resale value!

You can learn more about near zero energy homes at sites like:

builditsolar.com Half Plan (cut your energy use in half)

 Independence Energy Homes

zeroenergyhomedallas.com

Clarum Homes

 

 
 


 

 

 

Aug. 2007

 

 

 

 


     
 





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