What’s Wrong with My Current Furnace, Stove, or Radiator?

Absolutely nothing! In fact, you likely still require it. A heat pump can complement your existing combustion heater, leading to cost savings and lower emissions.

Most current home heating methods rely on combustion and heat transfer principles. Fuel (natural gas, propane, oil, or wood) is burned to generate heat, which is then distributed throughout the house via air or water. Furnaces utilize an integrated air handler (a large fan) to circulate warm air through ducts, while boilers send hot water through pipes to radiators.

For convenience, I will refer to furnaces, stoves, radiators, and boilers collectively as combustion heaters. It’s worth noting that electric resistance heaters can also be included in this group. When properly maintained, combustion heaters can produce a consistent amount of heat, regardless of external temperatures.

Although combustion heaters can be efficient, the fuels they rely on come with a significant carbon footprint and are often the largest source of emissions in a household. Additionally, fossil fuel prices can fluctuate greatly month-to-month. In contrast, an all-electric heating system has the potential to be cleaner, more cost-effective, and more efficient.

Understanding Heat Pumps

A heat pump (HP) functions similarly to an air conditioner (AC).

It’s crucial to stop equating heat pumps with combustion heating. Heat pumps are compressor-based reverse heat engines, similar to air conditioners, but with the added ability to provide heating.

In moderate temperatures, heat pumps are generally more cost-effective and efficient than combustion heaters. However, during extreme cold spells, heat pumps may struggle to provide adequate heating, necessitating the use of an auxiliary combustion heater.

Should I Replace My AC with a Heat Pump?

Absolutely! If you are considering a replacement for your AC, opt for a heat pump instead. If you currently lack cooling options, a heat pump is worth exploring.

A heat pump will cool your home as effectively as an AC while also providing heating during colder months. Since an AC is typically used for only a few months each year, a heat pump can be utilized nearly year-round.

Keep in mind that a heat pump may require an additional wire to connect to the thermostat for controlling both heating and cooling functions, and a smart thermostat may be necessary for optimal control.

Why Do Air Conditioners Still Exist?

Heat pumps often come with a higher initial price compared to similarly efficient AC units, and without careful tracking, it can be difficult to estimate their impact on your utility bills and carbon footprint.

Don’t be misled! Heat pumps may qualify for subsidies, making it easier to recoup the costs over time. Personally, I save around $100 annually on heating costs, and had the current subsidies been available at the time of my purchase, my heat pump would have been less expensive than an AC.

In today’s market, it’s challenging to find scenarios where opting for an AC over a heat pump makes financial sense. The primary factors driving AC sales seem to be a lack of familiarity with heat pumps and their seemingly higher price tag.

Returning to Your Existing Furnace, Stove, or Radiator

Upgrading to a heat pump or AC will not directly affect your combustion heater. If you switch from an AC to a heat pump, your combustion heater may remain untouched and serve as an auxiliary heating source. A system that includes both a combustion heater and a heat pump is classified as a Dual Source system.

To utilize your heat pump effectively, you may need assistance from an HVAC professional to install and configure a thermostat that switches between the heat pump for mild conditions and the combustion heater for extremely cold weather. Most technicians usually set the initial switch point at around 40°F (4°C), but finding the optimal temperature for your home can require some effort.

Do I Need to Keep My Combustion Heater with a Heat Pump?

It’s difficult to provide a definitive answer. In most cases, yes, you will likely need to keep it. The decision doesn’t have to be made immediately, as it can vary significantly depending on your home’s size, building materials, and local climate.

Consider an HVAC upgrade as a multi-phase project. Starting with a home that uses an AC for cooling and a furnace for heating, the first phase involves replacing the AC with a heat pump while leaving the combustion heater in place.

After the heat pump installation, see if you can endure a winter without activating your combustion heater. In many cases, the heat pump may struggle during the coldest days, necessitating the use of the combustion heater as supplementary heat. Maintaining a dual-source system can yield optimal results.

For those in smaller homes, milder climates, or with highly efficient heat pumps, it’s possible that the heat pump may become the sole heating solution. At this stage, you might contemplate removing the combustion heater altogether.

Keep in mind that ducted homes still require an air handler to distribute warm air. This component is integrated into the furnace, so simply removing the furnace isn’t feasible without replacing it with a dedicated air handler. Conversely, ductless heat pumps, like mini-splits, come with built-in fans and do not require additional air handling equipment.

Is It Possible to Achieve Zero Carbon Footprint with Auxiliary Heat?

Yes! Ensure you have access to a zero-emissions electricity source (consult with your provider). Then, select the highest efficiency heat pump your home can accommodate. Higher efficiency (HSPF/SPF) means that your heat pump will continue to function effectively at lower temperatures (below 0°F, -18°C as mentioned by some users).

You may find that some auxiliary heat is still necessary. Electric resistance heaters can serve this role, but keep in mind they are essentially oversized toasters.

Electric heaters use resistors to generate heat, which is often inefficient and more costly than combustion methods. If your electricity source isn’t clean, an electric heater can produce more emissions than a natural gas furnace.

However, if you utilize zero-emissions electricity, pairing resistive electric heating as an auxiliary source with a heat pump can be a practical approach for achieving emissions-free heating.

Quick FAQ

Q: What should I get to replace my old, broken furnace/boiler/stove? A: A new, essentially identical furnace/boiler/stove.

Q: What should I get to replace my old, broken AC? A: A heat pump with the highest efficiency your home can accommodate. It will provide the same cooling capabilities as an AC while saving on heating costs in the long term.

Q: I don’t have any way to cool my home and I want an AC. A: Opt for a heat pump instead.

Q: If I replace my AC with a heat pump, do I still need my furnace/boiler/stove? A: Try to get through at least one winter solely using the heat pump. If you’re confident that auxiliary combustion isn’t necessary, removal might be an option. If your home is ducted, keep your furnace! You’ll still need a method to distribute the air. If the furnace fan fails, you can replace it with an air handler, which is cheaper than a full furnace.

Q: I want zero emissions. What’s my best option? A: First, ensure your electricity is clean (consider solar panels or work with your utility). Then, replace your AC with a heat pump. If the heat pump is insufficient for your home’s heating needs, add an electric heater as your auxiliary heat source.

Q: All my equipment is functioning well! Should I still invest in a heat pump? A: New equipment comes with substantial carbon and financial costs. It’s advisable to replace only at the end of an item's lifespan. If you aren’t ready for a replacement, this is an excellent time to start monitoring your energy usage to understand heating costs at various temperatures. When it’s time for a replacement, you’ll be better equipped to evaluate the right system for your home.

Q: Where can I learn more about heat pumps? A: Check out my growing collection of articles on heat pumps!

In Summary: Rethinking Your Home HVAC Improvements

Dissociate the relationship between heat pumps and combustion heaters, as replacing one does not directly influence the other. A local HVAC installation expert can assist you in exploring your options. Here’s how to steer the conversation toward the right system for your needs.

Begin by inquiring about options for replacing your air conditioner with a heat pump. Grasp the efficiencies of the new units to estimate your cost savings and compare this with the additional installation costs of a heat pump over an AC. Investigate any subsidies or rebates available for heat pumps in your area.

Only after addressing these points should you ask if using a heat pump as a single heat source is practical. This may not be an immediate priority, but the insights gained can help inform your decision on whether to retain an auxiliary heating source in the future. By following these guidelines, you can secure a cost-effective, low-emission HVAC system.

Feel free to reach out with any questions in the comments, and don’t forget to check my other articles on heat pumps and HVAC systems.