Ceiling Fans

Behold the ceiling fan. That venerable throwback to days before AC, that reminder of lazy days on the verandah. This simple machine may seem like it's outlived its usefulness in today's home filled with complicated temperature-regulating gadgets, but it is still eminently useful, especially in these days of rising fuel and electricity costs. And not only can it help keep you cool in the summer, it can help keep you toasty in the winter! Read on to find out how...

In the summer, ceiling fans turn counterclockwise, which creates a breeze against your skin, creating a wind-chill effect and making you feel cooler. When you are hot, you sweat--simple enough. But it's the actual evaporation of this sweat that pulls heat away from your body. Circulation of the air rapidly increases the rate of evaporation. The more evaporation, the cooler the apparent temperature. This means that the air-conditioner thermostat can be set higher, saving you money!

Of course, it seems obvious to use a ceiling fan in the summer, but--while it may seem strange--they can actually be quite effective at saving you money on your heating bill during the winter. Heat rises. A large amount of heated air can collect by the ceiling before it can even be felt. In a room with 16-foot ceilings and the thermostat set at 68 degrees, the uppermost three feet of the room can reach 90 degrees or more before the heater shuts off--a huge waste of energy! In the winter, a ceiling fan's reverse setting operates the blades in a clockwise motion, producing an updraft, which forces warm air near the ceiling down into the living space. This mild circulation of air (low speed is recommended to avoid drafts) provides a more evenly heated room, shortening the time it takes the heater to work. In addition, the improved airflow in the room gives the thermostat a more accurate reading of temperature, helping you conserve energy.

So if you don't have a ceiling fan (especially in a high-ceilinged room), consider getting one. For a relatively small investment, you can rediscover an old way of saving money and energy!

Electrochromic Windows

Remember those sunglasses that would turn dark when you went out into the sun? Think of that idea applied to the windows of your home. Sound futuristic? Well, the future is now.

Electrochromic windows can block the glare of the sun with the flip of a switch, helping you save energy. Electrochromic windows are part of a new generation of technologies called switchable glazing or "smart" windows. Switchable glazing changes from transparent to tinted through the application of an electrical current, controlling the amount and kind of light that gets through a window into your home. Electrochromic windows can be set up to respond to sunlight, temperature, or an electrical control. By controlling the amount of light that passes through the window, these windows can reduce the amount of energy needed for cooling. The National Institute of Standards and Technology believes that smart windows can reduce a commercial building's energy use by 30 to 40 percent.

Mike Myser of Sage Electrochromics, makers of SageGlass, talks about electrochromic windows on bobvila.com:

"We're trying to change an industry. People want skylights, they want windows in their homes, the light it brings, but what do they do about the heat? We've solved that. Switchable control means controlling both the light and the heat."

The new Boeing 787 Dreamliner features electrochromic windows which replace the pull down window shades on existing aircraft. Better yet, here's an interesting application: There’s a bar in NYC where the bathroom doors are transparent when unlocked, and became opaque when locked.

Electrochromic windows are available from many sources. SageGlass is available to residential window manufacturers for exterior windows, doors, and skylights. While the cost of electrochromic windows can be from two to three times that of a standard window, the cost is expected to decrease significantly as manufacturing techniques improve and quantities increase. They use very little energy: the electricity used for switchable glazing is minimal compared with the energy savings they offer. Some require no energy at all. The National Renewable Energy Laboratory (NREL) has developed two types of solar-powered electrochromic devices that vary tinting based on the amount of sunlight they receive. The technology shows promise for controlling unwanted heat in skylights and windows without using an external electric source.

So be the first person on your block with the amazing glazing windows…or doors!

Geothermal Heating and Cooling

If you've been to Iceland (or Boise, Idaho), you've probably heard of geothermal heating, where natural hot springs are tapped into to provide steam and hot water to heat buildings. But did you know that there is a system that can provide low-cost, low-energy heating and cooling by taking advantage of the constant temperature of the ground just a few feet below your home? It's called a geothermal heat pump system, and here's how it works:

In most places, if you drill a few feet down into the ground, the temperature is constant year-round: around 50 to 70 degrees Fahrenheit depending on the location. Geothermal heat pump systems tap into this constant temperature: In the winter, heat energy is extracted from the earth and added to the building. In the summer, the process is reversed - unwanted heat is extracted from the building and added to the earth.

And the benefits are many:

Low Operating Cost
No Required Exposed Outdoor Equipment
Level Seasonal Electric Demand
No On-Site Combustion
Long Life Expectancy
Low-Cost Integrated Water Heating
Simplicity
Low Maintenance
No Supplemental Heat Required
Low Environmental Impact

Several residential buildings in New York City are already reaping the advantages of geothermal heat pump systems. At 360 Court Street in Brooklyn, a residentially converted church, geothermal heat pumps were selected by the developer because it was not possible to install exterior heating and cooling equipment on this historic building. And since geothermal heat pump systems require no external equipment (like roof fans or fuel tanks), the system was a perfect fit. Each apartment in this 34-unit building has its own geothermal heat pump and its own thermostat control.

The Department of Energy has a good pamphlet on geothermal heat pump systems for residential buildings.

Since these systems use heat pumps, it makes sense to get most energy-efficient heat pump available: gas-driven heat pumps. These are basically no different than other kinds of heat pumps: they transfer heat from a "source" to a "sink." However gas-driven heat pumps differ from other kinds of heat pumps in two fundamental ways: instead of an electric motor, a natural-gas engine powers the heat pump compressor; and in winter, heat recovered from the engine exhaust provides supplemental heating to the indoor space. Gas-driven heat pumps also have lower operational costs than other types of heat pumps.

Natural Cooling

This tip came to us through Green Building Blocks, a good source of information on green construction products and techniques.

Natural cooling systems incorporate shading from deciduous trees (for east- and west- facing glass), window overhangs and awnings, and radiant heat-reflective barriers installed in the attic space.

Benefits:
Natural cooling reduces the need for air-conditioning, saves money on energy bills, and makes homes without air-conditioning more comfortable.

Application:
Any combination of natural cooling techniques can be used to reduce overheating in homes. Use awnings and window overhangs primarily on south-facing glass to provide a balance between summer cooling and winter heating through solar gain. Use landscaping to shade east- and west- facing windows.

Looking for additional ways to keep the homes you build cool? Here are a few solutions to consider, from GBB’s Product Guide (which contains over 1500 independently-reviewed green products):

Scotchtint Plus All Season Films
Lutron Shading Solutions
Greenscreen Trellising System