​​​Should you buy a ne​w air conditioner and furnace together?​

How does a furnace work with an AC unit?

Your furnace and your air conditioning unit are separate components of your home’s HVAC system. The furnace is used to warm the house during the colder months, while the AC unit is used to cool it off during the warmer seasons. While they operate independently, there are some ways in which the two systems work together:

• Thermostat - the temperature in your house is set by the thermostat, whether you are using the furnace or the air conditioner. 
• Vents and ducts - the vents in your house are used to transfer warm air from the furnace as well as cool air from the air conditioner.
• Blower - both components use the furnace blower to move cool or warm air through the vents.​

When does it make sense to replace both at the same time?

An effective and efficient HVAC system should deliver consistent comfort by providing warmth in the winter and cooling in the summer. When faced with the scenario where one unit breaks down while the other is still functioning, it is understandable that you might opt for only replacing the malfunctioning unit. 

However, there are times when replacing both the furnace and the AC at the same time could be the best option.​

• Old age - if your still-working unit is 15 years or older, you may want to consider replacing it along with the unit that has malfunctioned.
• Performance - if you notice that the performance of both your furnace and the air conditioner has declined of late (with such signs as a reduced output of air or loud noises coming from the units), you may want to consider  replacing both. Mixing a poorly-performing old unit with a new one in your HVAC system could lead to increased issues with the older unit.
• Energy efficiency - if you notice that your recent energy bills have increased substantially, or that you’re not able to keep your home at a comfortable temperature throughout the year, it could be a sign that both units need to be replaced.
• Replacing your AC - an oft overlooked aspect of your HVAC system is that your air conditioner unit relies on your furnace for its blower motor. These components are used throughout the year, even when the furnace is not being used to warm your home. If you are replacing your AC unit​, it’s worth your time to look into how your new unit will work with your existing furnace.
• Installation costs and complications - having both your AC and furnace replaced at the same time can save money on the combined cost by not having to pay for two separate installation fees. Additionally, some homes have complicated installation processes due to the unit’s placement, making installation more labor intensive and, therefore, more cost effective when installed at the same time.
• Equipment sizing - having an improperly sized AC or furnace unit (units with too much or too little power) can lead to your home being too hot or too cold, and can reduce the lifespan of your units.
  

What are the benefits of replacing your AC and furnace at the same time?​

While replacing your AC and furnace simultaneously can result in a higher cost upfront, there are several benefits to replacing both units at the same time.

• Improved efficiency - replacing your AC and furnace at the same time with new, energy efficient equipment can increase your home’s energy efficiency and potentially reduce your energy costs.
• Promotions and special offers -  some manufacturers or service providers run special promotions throughout the year when buying both of their units together.
• Compatible systems - some HVAC systems have components that communicate to each other and the thermostat. When upgrading to a new unit, you want to make sure it will be able to communicate with the other unit, and this may work best when both units are purchased together.
• Convenience - combining the purchasing and installation processes of your furnace and AC unit can save you both time and money.​