By Carole Hawkins, [email protected]
The worst way to move energy around a house — that means heating or cooling — is with air, said Terry Frisenda.
But people do it every day when their central air conditioner blows cooled air through ductwork for the entire length of the house.
Frisenda, a regional account manager for LG Electronics U.S.A. Inc., sells mini-splits — a type of HVAC system that carries cooling, and also sometimes heating, throughout a house by way of refrigerant in small copper tubing.
Mini-splits are popular in remodeling situations when ducting is impractical. But the system also competes in new construction for its energy efficiency and its ability to create multiple temperature zones within a house, Frisenda said.
Like central air, mini splits use an outdoor condenser. But the system then distributes refrigerant to several small indoor units, which supply chilled or heated air to one or more rooms. Also called “ductless” air conditioning, the system has been used worldwide for 45 years, but is still relatively new in America.
At the August E-Council lunch for the Northeast Florida Builders Association, Frisenda laid out its advantages.
Energy efficient
The upfront equipment cost for a mini-split system is about 30 percent more per BTU than for a central air conditioning system, not counting the cost of ductwork, according to the U.S. Department of Energy.
But, mini-splits beat central air on operating costs because they are more energy efficient. Duct losses can account for as much as 30 percent of a house’s energy consumption, the department said.
Frisenda installed a mini-split system two years ago on a 2,500-square-foot home in Lakeland. Its air-conditioning bill today runs $22 per month.
Zoned heating/air conditioning
According to an independent industry survey, the top reason people are dissatisfied when they replace an HVAC system is because one part of the house is always too hot or too cold.
“It’s because by the time the air gets through the ductwork, it loses its heat or cooling,” Frisenda said.
With mini-splits, each indoor unit has its own thermostat, which means homeowners can set individual room temperatures.
Also, if there are rooms in the house that aren’t being used as much, like guest bedrooms, thermostats can be turned to different temperatures for better energy efficiency.
No ductwork
On a house with existing ductwork, replacing central HVAC with a mini-split costs more. But on new construction, ductwork costs disappear, making mini-splits a more attractive option.
Ducts are bulky, making them inconvenient to install in some situations, like:
• Room additions: When enclosing a porch or converting a non-heated space, the small 3-inch penetration needed by a mini-split is easier to accommodate.
• Architecture: Mini-splits can eliminate the need for fur-downs – boxed in areas of the ceiling – on homes that have no attic space for ductwork.
• Historic buildings: Mini-splits can better preserve the original structure when air conditioning is added, because the system doesn’t cut large holes into walls or ceilings.