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…)

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…)