Can You Add A Heat Pump To An Existing AC Unit Or Furnace?

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A centralized temperature-controlling system can make managing indoor heating more convenient than before. Now you’re wondering if you can install a heat pump on an existing furnace. Additionally, is it possible to add a heat pump to an AC unit? We researched for you and consulted with industry experts to give you the following answer.

It’s possible to add a heat pump to an existing cooling or heating system. However, homeowners need to think about certain factors to accomplish a proper installation. The nature of the existing indoor temperature control system, the home’s ductwork, and electrical wiring are some elements that may or may not allow these setups.

Proceeding with these projects often requires sufficient knowledge about different matters, including wiring electronics. Continue reading as we talk about the process to wire a heat pump to a furnace in closer detail. We’ll also tackle the possibility of adding a heating unit to an air conditioner.

A gray colored air heat pump installed outside a house, Can You Add A Heat Pump To An Existing AC Unit Or Furnace?

Can A Heat Pump Be Installed With An Existing Furnace?

You can install a heat pump to an existing gas furnace by using a dual fuel system. This framework uses a split or packaged unit to pull energy from two sources: electricity and gas. The resulting construct combines the heating consistency of the existing gas furnace and the heat pump’s improved temperature-providing performance.

How To Add A Heat Pump To Existing Furnace

Two Hvac air conditioning units placed in the side of the house

Proper wiring is essential to create the dual or hybrid heating system brought by a furnace and heat pump. Additionally, a thermostat should connect the two heating units, and it’ll act as the temperature control center for the home.

Check out this thermostat on Amazon.

The resulting setup allows the thermostat to regulate the temperature automatically and more efficiently than before. First, the thermostat will increase the premises’ temperature to a certain temperature using the heat pump. Then, once the outdoor ambient temperature reduces to a specific level, the thermostat will activate the furnace to support the system.

Before proceeding, be wary that you shouldn’t run both heating units in ‘Heat Mode’ simultaneously. Otherwise, the system’s overall heat will exceed normal levels, causing issues like physical damage to the heating agents and dehydration to household members and guests.

Take note that the items needed for this operation should come with the different devices involved. Don’t hesitate to reach out to your local hardware store if you lack certain components for this setup.

Finally, make sure you have sufficient knowledge about electronics, particularly with connecting wires. Otherwise, you should leave this project to certified technicians to prevent expensive mishaps.

After completing the necessary preparations, you can move to the next step of this operation.

Step-by-Step Guide

  1. Connect the red 24-volt wire from the furnace’s control board to the thermostat.
  2. Attach the orange wire from the thermostat to the furnace’s board. Make sure that this connection goes through the heat pump’s board for the thermostat to automatically reverse the cooling mode when necessary.
  3. Link the wire in the yellow or 'Y' terminal from the thermostat to the furnace’s board. Then, connect the same wire to the heat pump’s board.
  4. Connect the green wire from the thermostat to the appropriately labeled terminal in the furnace’s board. You’ll know that it’s the correct station if it has the letter ‘G’ adjacent to it.
  5. Join the aux/e terminal from the thermostat with a white wire to the 'ww1' station in the furnace’s board.
  6. Connect the 'w2' terminal of the heat pump’s board with the same white wire used in the previous step to the furnace’s 'ww1' station.
  7. Use black and brown wires for the thermostat’s 's1' and 's2' terminals and connect it to its outside temperature sensor. Ensure that this connection runs through the furnace’s board.

Watch the video below to learn more about these steps in greater detail:

After finishing the setup, you may need to use the emergency heat in some scenarios. If so, you can read our post on the right time to use the emergency heat setting on a heat pump for you to learn more about this particular feature.

Can I Add Heat To My Air Conditioner?

A huge house with two air heat pump placed on the front lawn

Many air conditioning systems, especially central models, often have heating equipment to supply sufficient warmth to homes. Although this possibility exists, it might not be a cost-effective solution to install a heat pump to an existing AC. Consult with a certified indoor heating specialist if you’re unsure about your options.

At What Temperature Do Heat Pumps Become Ineffective?

A boiler room in the basement of the house

Heat pumps generally become ineffective if the outside temperature falls between 25 to 30 degrees Fahrenheit. At this temperature range, the air in the area should freeze moisture. In turn, the potency of a typical heat pump would lose efficiency as it struggles to supply warmth.

Properties in regions that experience this issue might install backup heating systems. These options may include:

  • Natural gas furnace: Ideal for emergency heating without the worry of paying for significant electricity costs.
  • Electric heat strips: Supplementary heating sources with fairly reasonable pricing structures. Although, these products might only increase the supplied heat up to a certain extent.

Check out this electric strip heat kit on Amazon.

How Much Does It Cost To Add A Heat Pump?

A heat pump’s overhead often depends on its type. The following are the average costs to expect when purchasing and installing a new heat-pumping system:

  • Geothermal: $13,000 to $36,000
  • Gas: $4,300 to $8,000
  • Air-Source: $3,300 to $7,500
  • Ductless Mini-Split System: $1,500 to $5,000

Other factors that influence the total costs of adding a heat pump include:

  • Size
  • Brand
  • Seasonal Energy Efficiency Ratio (SEER)
  • Heating Seasonal Performance Ratio (HSPF)
  • Professional Labor

If you’re looking at furnaces, keep in mind that these heating systems don’t usually use SEER ratings to measure their supplied heat. Read our post on the SEER rating to learn more about this energy-efficiency coefficient.

What Is Cheaper To Run Heat Pump Or Gas Furnace?

A black colored air heat pump on the side of the house

Some scenarios entail running heat pumps to be less expensive than using gas furnaces. However, some cases might also create ideal cost-effective setups to allow gas furnaces to require fewer expenses than heat pumps.

It’s advisable to look at this matter in terms of value instead of overall expenses. For instance, gas furnaces often provide better value than heat pumps.

Homeowners using natural gas-powered furnaces can expect to pay $260 to $1,550 in annual energy costs for these systems. That range fits well into the national average of paying $661 in natural gas costs.

On the other hand, a sealed-system boiler may deliver reduced heating costs. Moreover, this option is usually less laborious to install than other heating frameworks. In turn, installation, maintenance, and usage expenses are generally less expensive with the boiler than other heating systems.

But you may also save money on professional labor costs if you opt for DIY installation and maintenance procedures. If so, you can save from $850 to $5,500. Moreover, you can gain additional skills by familiarizing yourself with your chosen heating system.

Final Words

A gray colored air heat pump installed outside a house

The possibility of installing a heat pump to an existing AC or furnace exists. Check your home’s current heating setup if adding an extra heating unit is a feasible solution. Also, proceeding with these projects typically requires expertise on different matters, which means you may need professional help to experience pleasing results.

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