HYBRID/ADD-ON/Dual-Fuel Heat Pumps

They all mean the same thing. A dual-fuel heat pump is an electric heat pump and a gas or oil furnace all in one. A heat pump is the most efficient way to heat your home above freezing. In those few instances when the temperature drops below freezing, a furnace provides heat more economically. By combining the two, you can have the benefits of both systems.

How it works

When the temperature is above 35 degrees or so, the dual-fuel heat pump uses electricity to transfer outdoor energy (heat) into your home as necessary. This type of heat circulates evenly throughout your home, and isn't too dry. When it gets really cold outside (around 35 degrees or lower), the heat pump automatically switches to supplemental gas or oil heat for better efficiency. In other words, the electric resistance auxiliary heat found in conventional air-to-air heat pump systems is replaced by the gas or oil furnace. Because there are advantages and disadvantages to both a heat pump and gas/oil furnace based on the outdoor temperature, the dual-fuel solution really does give you the best of both worlds. It's the most comfortable heating system at any outdoor temperature, as well as one of the most efficient, versatile, and economical heating-and-cooling systems you can buy. It also gives you the option of how much of which one depending on higher or lower fuel costs. The add-on heat pump unit is popular for installation on older homes with central systems that were not previously air conditioned, or for homes whose cooling system needs replacing and the furnace is still in good shape. Besides providing air conditioning, add-on heat pumps increase the overall efficiency of the heating system because both the heat pump and the fossil fuel furnaces are operating at their optimal efficiency levels.

Cost

A dual-fuel unit costs more than conventional heating and cooling systems because you’re getting essentially two systems in one. But the amount you'll save in the next two to three years from lower heating costs will more than make up the difference you'll spend on a better system.

Choosing a system

There are several different brands and models to choose from. The most noticeable differences between them will be the price, and whether they'll be installed inside or outside your home. There are fewer packaged models available on the market. These systems are also more expensive than split systems.