Furnaces and boilers are the primary heating source of most homes in America. Both boilers and furnaces are rated by their annual fuel utilization efficiency, or AFUE, which measures the percentage of fuel that is wasted through their normal operation. Old, low-efficiency systems can squander nearly half of their fuel. New, high-efficiency systems utilize more than 98 percent of their fuel. The best system, the worst system, and every system in between can benefit from supplementary heat from a cost-effective, efficient, electrical split-ductless system to offset wasted fuel and cost, while optimizing comfort and control.
Furnaces work by heating air and then distributing that air through ductwork and vents throughout the home. A furnace's Annual Fuel Utilization Efficiency (AFUE) does not take into consideration the amount of heat lost when traveling through ducts, which can add up to a loss of up to 35 percent if ducts run through cold attics or garages. That waste is on top of normal energy loss and fuel waste calculated by the furnace's AFUE.
Closing vents in unused rooms of a furnace-driven heating system offers only limited zone control. By installing split-ductless heat pumps in commonly used rooms, homeowners can rely less on their furnace — even the most efficient of which is less efficient than a heat pump — and dramatically diminish the amount of fuel lost to the operation of the furnace itself, as well as the heat that escapes on its journey through ductwork.
Boilers produce heat by boiling water and delivering either steam or hot water to radiators, heat pipes, radiant floor systems, baseboard radiators or air-heating coils. Boilers use either oil or natural gas as a fuel source, and are required to have a minimum AFUE of between 80 and 84 percent. Since boilers are not permitted to have perpetually running pilots, a thermostat has to do its best to automatically regulate the temperature of the water to match the amount of heat required.
By providing supplementary heat through one or more ductless heat pumps, the amount of required heating can be regulated through precise thermostats in individual rooms and zones. This takes the burden off the boiler, and its inexact master thermostat.
Many consumers who install ductless heat pumps never intend to use them as their home's primary heat source. Modernized, efficient boilers and furnaces can do the heavy lifting, but the amount of fuel they waste and the level of heat they lose can be dramatically reduced when they're supplemented with strategically placed ductless heat pumps.
This article and its content are sponsored by Mitsubishi Electric US Inc., Cooling & Heating Division.