The Gossamer Wind Ceiling Fan is EnergyStar rated and incorporates an advanced blade design that greatly improves energy efficiency.

I always stress that the design of a green home must start with the passive-solar-design elements before even thinking about the mechanical systems. If you focus on the overall efficiency of the entire building, you can then reduce or eliminate the electrical/mechanical systems—such as heating and cooling.  My straw bale home is designed to stay comfortable on hot summer days without the need for a conventional air conditioner. This is accomplished by careful window placement to prevent solar gain in the summer, well-insulated straw bale walls, R-55 cellulose insulation in the ceilings, and the use of interior thermal mass walls.  When the overall building is designed properly, you may find that you only need to reduce the interior air temperature by a few degrees—instead of twenty or more degrees. A ceiling fan may then be all that is needed to make a room feel comfortable. In the case of my straw bale house, a conventional air conditioning system would not only be unnecessary, it would also greatly increase the cost of the off-the-grid photovoltaic system that supplies all of the electricity for the home.

The Concept of the Ceiling Fan
Ceiling fans have made a comeback due to their energy efficiency. They were invented in the 1860’s to 1870’s and were the standard method of making buildings more comfortable for decades.  By the mid 1950’s, electric air conditioners began to appear in homes and the sales of ceiling fans waned. An electric motor spinning a propeller-type fan blade uses a lot less electricity than an air conditioning system that has both blowers and compressors. Dropping the apparent temperature of your skin is much easier than cooling an entire room. Ceiling fans work by evaporating moisture off your skin with moving air, just as a summer breeze can make a hot day seem quite comfortable. (more…)

Photovoltaic panels generate clean power by converting sunlight into electricity. This article will talk about the actual—verses the rated—power output of photovoltaic panels. Do not assume that a PV panel rated at 170 watts of power will actually give you that amount. It will probably be closer to 150 watts per panel. Because of the difference, care must be used when sizing the system for your electrical needs. Otherwise, you may find that you are generating less power than you need.

Designing a photovoltaic system for your green home starts with using energy efficient appliances and lighting inside the house. My rule of thumb is that it is cheaper to buy a new EnergyStar-rated refrigerator for under $1,000 than to spend an extra $2,000 on photovoltaic (PV) panels to power an old, inefficient refrigerator. The same goes for other appliances—particularly those that get a lot of daily use such as televisions.

The photovoltaic system for my small straw bale home (featured on the BuildingWithAwareness.com website and DVD video) cost around $12,000 in equipment. Without carefully choosing the most efficient appliances and  lighting, the cost would have been dramatically higher.  (more…)

This article will show how to attach commercially available solar panel mounting brackets to a corrugated metal roof that lacked flat surfaces. In the photo above, a ladder was used to slide the PV panels to the roof.

Photovoltaic (PV) panels produce all of the electricity for this straw bale hybrid home from sunlight. All of the PV panels are permanently attached to the south facing pitched roof.  Standing-seam metal roofs are partially flat, so mounting a rack is not a problem.  The roof on my house is corrugated metal and therefore has no flat surfaces for the aluminum mounting brackets to seat.  A stout connection is essential for the photovoltaic panels to survive high wind loads and to create a waterproof seal where the bolts penetrate the roof surface. What we needed was a mounting platform that both comformed to the convolutions of the metal roof and also had a flat surface for the foot bracket to contact.

Here is how we solved the problem. (more…)

Product Tested: ShurFlo Deluxe 24 volt DC model 2088-474-144 on-demand diaphragm pump, 3 gallons per minute output, with builtin 45psi pressure demand switch. Suggested retail price: $172.00

Ideally, a water pump for a rainwater cistern will use very little electricity, be durable and rugged, and be as maintenance free as possible. The model being reviewed was in daily use for 8 years in a small straw bale house.  Water from the cistern delivers naturally soft water to the washing machine, the toilet, and a hose bib. A 24 volt model was chosen so that it could run directly off a 24 volt photovoltaic (PV) electrical system for this off-the-grid green home. Although the PV system included a 120 volt AC inverter, it was desired to have the pump run off the DC side as this would  guarantee that the pump would have power even if the inverter was not operational. The DC pump would also be more energy efficient as some efficiency is lost by the inverter. This same pump model is also available in 24 volt and 120 volt configurations.

The advantage of a rubber diaphragm pump is that they are very immune to damage from grit and debris in the water. This is important as water is collected off the roof with only a simple sand filter. (more…)