When it’s time to replace your home’s heating system, there are several options to consider. Furnaces, the traditional choice, remain the most common way to heat homes across the United States. However, heat pumps, which have become increasingly popular, actually outsold furnaces for the first time in 2023. To help you make an informed decision, let’s break down the key differences between these two heating solutions.

Short-Term Versus Long-Term Costs

When it comes to upfront expenses, furnaces generally have a lower equipment cost compared to heat pumps. However, the installation of a fuel-burning furnace tends to be more complex and costly due to the need for gas piping and a venting system. A furnace must have a venting system to expel combustion byproducts like carbon monoxide. Even with these additional installation steps, the overall initial cost of a furnace is typically lower than that of heat pumps because of the expense of the heat pump itself. A heat pump is typically 20% to 50% more expensive to purchase than a furnace.

However, the two systems differ significantly in long-term operating costs and efficiency. Furnaces, especially older or non-condensing models, lose a significant amount of the heat they generate through venting. The combustion process inside a furnace generates heat by burning fuel, producing hot exhaust gases. These exhaust gases must be vented outside through a flue or chimney to prevent harmful gases like carbon monoxide from building up inside the home. As these hot gases escape, a portion of the heat they carry is also lost to the outside, reducing the furnace’s overall efficiency.

Modern high-efficiency furnaces, called condensing furnaces, reduce this loss by capturing some of the heat from the exhaust gases and reusing it to heat your home. However, even with these improvements, the combustion process in furnaces remains less efficient than the heat transfer method used by heat pumps.

Heat pumps, by contrast, don’t generate heat through combustion but instead transfer it. They use refrigerant to absorb and move heat between the inside and outside of your home, making them more efficient.

Primary Power and Fuel Sources

Most heat pumps operate by consuming electricity. There are electric furnaces, but they’re uncommon due to the cost of electricity. Electricity use isn’t an issue with heat pumps due to how much more efficient they are. Most furnaces in American homes burn fuel. Natural gas has traditionally been the most popular fuel option. It’s relatively cheap and clean. Natural gas is also convenient if you can access a municipal gas network; it’s automatically piped to your home. The most prevalent options for homes without access to natural gas are propane and fuel oil. These are fuels that homeowners have delivered and stored on their properties in tanks.

Components

The components of heat pumps and furnaces differ significantly due to the way each system operates. Heat pumps use parts similar to air conditioners, including an evaporator coil, condenser coil, compressor, and pumps to move refrigerant. In contrast, furnaces rely on an ignition system to produce heat. Gas and oil furnaces feature combustion components like burners, a pilot light, and a heat exchanger, while electric furnaces use a heating element to generate warmth. Both systems use a blower to circulate air throughout the home and a filter to remove dust and other particles from your home’s environment.

Safety Considerations

Modern heating systems are well-regulated and have many safety mechanisms. That said, there are additional safety considerations with all fuel-burning heaters. Furnaces that burn oil or natural gas create carbon monoxide (CO) as a byproduct. If there is a heating system problem, CO can mix with your air supply and cause CO poisoning.

Temperature of Heated Air

When the heated air from a heat pump reaches your living spaces, it’s generally between 85 and 90 degrees Fahrenheit. On the other hand, the air from a furnace is usually between 120 and 130 degrees. While 85 degrees is plenty warm enough to heat your home, some homeowners prefer the instant heating provided by furnaces.

Heating Output at All Temperatures

A benefit of furnaces is that the heat output is consistent and not affected by outdoor temperatures. This is not the case with heat pumps. As temperatures fall, less ambient heat is available for them to transfer into your home. Heat pumps have trouble keeping your home comfortable as the weather drops below freezing. Most models have an auxiliary heating strip to solve this problem. However, running a heat pump in auxiliary mode consumes a lot of electricity, similar to baseboard heating.

Heating and Cooling

A heat pump works similarly to an air conditioner by using refrigerant to provide cooling. However, it also features a reversing valve that enables it to switch modes and provide heat as needed. In contrast, a furnace is designed to provide heat exclusively. If cooling is required, it must be paired with a central air conditioning system.

Inside Versus Outside Installation

Heat pumps operate as split systems, meaning their installation involves indoor and outdoor components. Specifically, the indoor unit handles air distribution and temperature control, while the outdoor unit, primarily the condenser, is responsible for expelling heat. In contrast, all equipment associated with a furnace is installed indoors.

Maintenance Requirements

Both furnaces and heat pumps require seasonal maintenance. Most HVAC warranties require it. An annual tune-up by a professional reduces operating costs, helps avoid repairs, and ensures a system ages more gracefully. Furnaces need a tune-up in the fall before the heating season. Heat pumps need that, too, but also a tune-up in spring before the cooling season. The nature of the maintenance is different, too. Primary tasks with heat pumps include cleaning the evaporator and condenser coils. Main tasks with furnaces include cleaning the combustion equipment and ensuring that the system is venting gases properly.

Energy-Efficiency Ratings

Energy-efficiency ratings for heat pumps and furnaces are measured differently. For furnaces, efficiency is assessed using the annual fuel utilization efficiency (AFUE) rating. AFUE measures how effectively a furnace converts fuel into heat over the course of a year. For instance, a furnace with an AFUE rating of 90% converts 90% of the fuel it consumes into heat, with the remaining 10% lost as waste. Generally, a higher AFUE rating indicates a more efficient furnace, which translates to lower operating costs.

On the other hand, heat pumps use the heating seasonal performance factor (HSPF) to gauge their efficiency. HSPF measures the heating performance of a heat pump over a winter season. It reflects how well the system heats your home compared to its energy consumption. A higher HSPF rating means greater efficiency.

Your Local Heating and Cooling Professionals

At [company_name], we are a family-owned business that has been serving the residents of San Antonio, TX and the surrounding areas since 1985. We install, repair, and maintain heating and cooling systems. Additionally, we can help with all your indoor air quality, ductwork, and smart thermostat needs. Contact us today to schedule an appointment with one of our experienced team members for our heating services.