In this segment, host Paul Ryan visits the residence of Alvin Sain -- a home that, because of its design, is one of the most energy-efficient homes anywhere in the US. The 2000-square-foot house on the outskirts of Pittsburgh was built in the year 2000, and its creation was based on an attempt to push the envelope on energy-efficient design.
Before he began building the house, Sain worked as a professional engineer and learned about a lot of new technologies designed to enhance home energy-efficiency. He decided that he wanted to build a house that utilized as many of those technologies as possible. He began work planning and building a house following a list of guiding principles and design constraints including:
- Making the house energy efficient
- Making the house healthy and safe
- Meeting all of the requirements of the American Lung Association for a health-house
- Using earth-friendly materials
- Keeping the costs below $200,000
- Completing the project within the span of 15 months
- Meeting all local building codes
- Make the house easy to maintain and a joy to live in (more livable)
Foundation, Exterior Shell and Windows
The quality of the thermal shell began with the foundation and basement wall using insulated concrete forms (ICFs) for a high-mass wall with an R-value of 20. The forms consist two outside layers of foam held apart by plastic ties. The concrete was poured directly into the forms (figure A). This system allowed the owner to construct the forms himself and get the assistance of a crew for pouring. The resulting wall is thermally sound and provides a nice structure that is easy to waterproof.
The roof and walls were constructed using structural insulated panels (SIPs) ( figure B) manufactured by R-Control B.. The panels have foam centers and arrived at the building site cut and ready for assembly. The wall sections are simply fastened to 2x6 base plates with staples. The roof assembly is similarly straightforward, with large screws securing the roof to the walls. The foam centers serve the same purpose as fiberglass insulation in a standard house. R-values for the roof and walls are R-23 and R-38, respectively and the joints are sealed with a patented product combining glue and flexible sealant.
The windows and doors are aluminum-clad wood framed with high-performance double glazing. The double-glazed windows (figure C) are argon-filled, and are highly energy-efficient. The french doors have a special lock which not only provides the security of a deadbolt, but also pulls the door tighter against the seal.
Heating, Cooling and Ventilation
The house is heated with radiant-floor heating using a VoyagerB. high-efficiency gas water-heater (figure D). The water-heater has a 45-gallon capacity and is rated at 100,000 BTUs. It is quite efficient at converting gas to heat, with a recovery efficiency of 94 percent and an annual energy factor (AEF) of 86. This unit will provide all of the heat for the house and the hot water needs of the occupants under almost any condition.
The house is divided into five heating zones: living room, master bedroom, basement, garage (radiant floor), and remaining rooms. The heating system uses a single pump to direct water into separate tubes (figure E), each dedicated to a particular zone. During construction of the house, the tubing was laid out in the floor and concrete poured over it. Hot water flowing through the embedded tubes heats the entire floor. This type of radiant heat is not only efficient, it is considered to be more comfortable than hot-air heat -- allowing the thermostat to be set back while the house is still kept comfortably warm. The separate zones allow the heating of the house to be fine-tuned to further save energy.
The air-conditioning system is a split system consisting of an air-handling unit (AHU) located in the center of the upstairs and an A/C unit located outside the house. The outdoor unit cools a refrigerant and pumps it into the house, into the cooling coil located below the AHU. Return-air from the rooms is circulated down through the coil where it is cooled and distributed to the house.
The ducts and AHU were sized to match the 2-ton A/C unit. All duct seams were sealed with foil tape and all flex connections and metal duct seams were sealed with mastic. The system achieved very low leakage rates and highly efficient flow rates. Since the actual efficiency on A/C units is typically low at the beginning of a cycle and levels off later, correct sizing will extend the running time each cycle, improving the efficiency.
The Lifebreath B. clean air furnace combines the air handling unit and heat recovery ventilator (HRV) in one unit. The HRV (figure E) brings in fresh air from outside and exhausts the same amount of stale air from inside.
Building an airtight house can create problems with stale air -- which is why the house is equipped with a heat recovery ventilator (HRV) unit. If fresh outside air were introduced directly into the air-handling system, it would be uncomfortable. This HRV (figure F) tempers the air brought into the system from the outside -- warming it in the winter, and cooling it in the summer. It does this by transferring heat from the outgoing air stream to the incoming fresh air. Heat is exchanged at a rate of 67 percent. A hot water coil tied to the radiant heating system provides the necessary heat, eliminating the need for an additional combustion source. With this system, the fresh air that ends up in the house is always at a nice, even temperature.
All of the systems shown in this segment were all professionally installed on this house during the construction process. According to Alvin, however, the same or similar systems could also be incorporated into a home addition or major re-model of an existing house.
In this segment, host Paul Ryan once again visits the residence of Alvin Sain -- an experimental home that tests the limits of energy-saving technology. Because of its carefully thought-out design, this is considered to be one of the most energy-efficient homes in the US.
Sain's career as a professional engineer taught him about a lot of new technologies designed to enhance home energy-efficiency. He decided that he wanted to build a house that utilized as many of those technologies as possible. This segment focuses on some of the innovative energy-saving devices used inside the home.
Home Automation System
An X-10 home automation system allows lighting and heating to be controlled from anywhere in the home. It utilizes the standard wiring in the walls as the communication network, so no additional wiring is needed to put the system into use. It simply uses transmitter and receiver modules (figure A) to control signals that turn electrical devices on and off.
Electrical devices, such as a table lamp, are simply plugged into a receiver module (figure B) which is, in turn, plugged into a standard wall outlet. A numeric code is set on the receiver, which is now ready to receive a signal. The transmitter -- also plugged into a wall outlet -- is set to the same numeric code as the one being used by the receiver. The transmitter can then be used to turn the lamp on and off from anywhere in the house -- as long as it's plugged into a wall outlet.
The system can be used to control other electrical devices throughout the house, such as thermostats, outside lights, alarm systems, etc. The system used here features a "sleep" button, which automatically turns off outside lights and lowers the thermostat (figure C) at night, thereby reducing energy consumption.
Installation of this home automation is an easy project for any do-it-yourselfer.
Water-Saving Devices
In bathrooms and kitchens located far away from a home's water-heater, it can take several minutes for hot water to reach the spigot once the hot-water faucet has been turned on. This results in wasted water and energy. In Sain's bathroom, a on-demand circulation pump. To get hot water immediately, a button on the basin cabinet is pushed. The switch engages the pump (figure D), which draws water from the hot water tank and simultaneously pushes the cold water in the pipes back into the tank. When the pump senses the hot water has arrived at the sink, it shuts off. Water and energy are both conserved because, rather than letting the water to flow until it gets hot, the pump does the work of transferring the water from the heater.
The installation of a pump like this is fairly easy. It comes with two flexible hoses -- one for hot water and one for cold. Plumbing t-valves (figure E) need to be installed on both the hot and cold side of the existing plumbing to accommodate the hoses. Additionally, since the pump has an electric motor, a wall-outlet may need to be installed beneath the sink. This may require the services of an electrician. The cost of this particular pump is about $200.
To further reduce hot water consumption, a pedal valve is installed at the kitchen sink. Foot operation of the valve (figure F) causes water to flow from the spigot (figure G) without turning on the regular faucet controls. This reduces wasted water during such tasks and rinsing dishes and washing hands. It can also save energy, since it may reduce use of hot water for ordinary washing and rinsing tasks.
Following the manufacturer's instructions, installation of the pedal valve is fairly simple. A hole is cut in the bottom of the cabinet, the pedal is dropped through the hole, and the valve is mounted to the cabinet bottom. There are four hoses leading attached at the back -- two connected to the hot and cold supply, and two connected to the faucet. The water simply bypasses the original plumbing, and is connected directly to the faucet (figure H).
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