5 Fine Energy Efficiency Technologies

Geothermal
Dehumidification and reheat capabilities are among the most useful new advances in the geothermal arena, according to Joel Sigman, president, indoor climate solutions division, Sigman Heating and Air Conditioning/Sigman Indoor Climate Solutions LLC, Belleville, IL.

"Geothermal technology is already the most efficient way to heat and cool a space, and a reheat feature on a geothermal unit allows you to heat the water in a swimming pool, or dehumidify spaces such as indoor swimming pools or spaces in which artwork or other valuables will be stored, virtually for free," Sigman says. (See a sample Sigman project at http://bit.ly/sigmanprojectcb)

Variable-speed motors and two-stage compressors also have been welcome options for geothermal system designers to present to potential customers, Sigman says, and the addition of tin-coated coils to some manufacturers' product lines should help improve the longevity of coils by protecting them from damage caused by indoor air quality hazards, such as volatile organic compounds (VOCs).

Sigman adds that one of the biggest drivers in the geothermal market right now is the green movement — as in the green money that customers can save thanks to the 30% tax credit that's available for geothermal units through 2016. "The geothermal industry often talks about the importance of customer education, and a 30% tax credit is certainly one fact about geothermal that your customers really need to know," he says.

On Sigman's wish list: control panels that would allow service technicians to proactively analyze a unit or system and identify when it isn't functioning properly — before a breakdown occurs. "I know it's possible, because they have that type of capability on the commercial side," Sigman says. "I'm looking for someone to figure out how to cost-effectively bring it to the residential market."

High Velocity
High velocity systems are benefitting from variable air volume speed blowers and zone controls, according to George Gittinger, Design/Build manager, TUDI Mechanical Systems, Pittsburgh, PA.

"It's a big plus to be able to put multiple thermostat zones on one high velocity system," Gittinger says.

He adds that TUDI is beginning to combine high velocity and geothermal systems for some high-end homeowners, especially those who live in historic homes.

"The combination of geothermal and high velocity is great for these homes," Gittinger says. "Inside, they don't have a lot of room for ductwork. The small duct openings are perfect for maintaining historic character. Outside, they don't want equipment that will distract from the aesthetics of the house. It's a nice solution, inside and outside."

Customer education is an important element of the high velocity business, Gittinger adds. He advises educating potential customers about the effect of aspiration.

"Customers look at a 2-in. round hole in the ceiling blowing straight down, or in the floor blowing straight up, and they can't image how the conditioned air is going to circulate into the center of the room. But because it's moving at such a high velocity, even a small air stream aspirates or entrains the air around it and creates an air movement to involve the whole room," he says.

Customers may also be interested to learn that high velocity systems, such as SpacePak, are often better humidity removers than traditional systems, according to Gittinger.

"The coils are a little thicker and a little colder in a high velocity system than in a traditional system, and they actually have a little bit less air passing over," he says. "In essence, that gives them a better dehumidification capability."

Hybrid
Hybrid systems can take many forms, and the term can refer to pre-packaged units that combine two technologies, or custom designed systems made up of a combination of forced air, hydronics, geothermal, and any other HVAC technologies that a contractor applies to solve a comfort challenge in a highly efficient way.

At 72 Degrees Heating & Air Conditioning, Sanford, NC, Operations Manager David Vinson prefers hybrids that combine a heat pump and a gas furnace. Such systems, he says, can reduce customers' heating costs by up to 60%, especially if customers are using propane for wintertime heating.

"Obviously the cost of electricity is cheaper during the wintertime than the rising cost of propane," Vinson says. "The price of a hybrid system isn’t much higher than the price of either a furnace or heat pump alone. There are a few extra controls with a hybrid system, but otherwise there's not a huge cost difference. That makes the payback period for the homeowner pretty short."