Conventional Vs. Heat Transfer Furnaces

Conventional

• A conventional furnace is commonly referred to as a “Type B” furnace and is fueled by natural gas, propane or oil. The majority of conventional furnaces are found in older homes. Conventional furnaces have the some of the lowest energy efficiency ratings of furnaces in use, ranging from 55 percent to 78 percent. In 1993, the federal government required all new conventional furnaces to have a minimum energy efficiency rating of 78 percent. Many older conventional furnaces vent exhaust fumes through a home’s chimney system, while newer, high-efficiency models can vent directly through walls to the outdoors.

Heat Transfer

• Heat transfer systems convert and transfer heat from the soil, the water or the air, hence the term “heat transfer.” For example, geothermal heat pumps leverage the Earth’s ability to store heat in the ground. Ground temperatures typically remain constant, between 45 and 75 degrees Fahrenheit, depending on the region and climate, according to the U.S. Department of Energy. In a heat transfer system, the stored heat is moved through pipes buried below ground to the home, and transferred and pumped into the home. During the summer, a geothermal heat pump and heat transfer system reverses and transfers heated air from the home back to the ground to keep the home cool.

Similarities

• Conventional and heat transfer systems are both components of a home’s overall heating ventilation and cooling system. A conventional furnace does the lion’s share of its work during the winter heating season and turns over activities to the condenser and compressor components of the HVAC system in the summer to provide indoor cooling. A heat transfer heat pump system also provides heating and cooling. You can combine a conventional furnace with a heat pump as a back-up during severe cold weather. This type of system is called a hybrid system or a dual-fuel heat pump. Just as conventional systems use different types of power and fuels (gas, propane, oil and electricity), heat transfer systems can use air, water and thermal energy to generate heat.

Differences

• Heat transfer systems and heat pumps have actually been around since the 1940s, but they are still considered to be a new alternative. Conventional systems are easy to understand -- you buy gas, oil, propane or electricity, then you turn on your thermostat to a desired temperature, your home is heated or cooled, and the utility provider bills you for the energy you used. Geothermal heat transfer systems are more complicated; dependent on the heat stored below ground level, and some systems might not be as effective in cold climates, such as areas of the upper Midwest and Northeast. A heat transfer heat pump system can cost as much as $10,000 and more to install, as opposed to a conventional HVAC system, which could cost $5,000 and up, as of publication. According to EnergySavers.gov, new all-climate heat pumps on the horizon will work in temperatures down to minus 15 degrees and reduce heating and cooling costs by 20 to 60 percent each year.