How to Know if You Can Add Air Conditioning to a Heat-Only Home

This is one of the most common questions we get from buyers touring homes without air conditioning: Can I add A/C?

The short answer is yes—you can add A/C to almost any home. The longer answer? It depends on the home’s existing heating system, the budget, and how much work you're prepared to take on. Here’s a quick breakdown of what to consider when evaluating this with your clients.

Key Factors to Consider:

1. Forced Air Furnace = Easiest Path
   If the home already has a forced air furnace, that’s great news. The ductwork is already in place, so installing a central A/C system is typically straightforward and cost-effective.
   

2. Boiler System = Bigger Lift
   Homes heated by a boiler (radiators, baseboards, etc.) do not have ductwork, so adding central A/C will require installing a separate duct system. An increasingly popular alternative? Ductless mini-split systems, which are easier to retrofit and provide room-by-room control.
   

3. Evaporative Cooler Present?
   It’s a common misconception that an existing swamp cooler limits your A/C options. In reality, evaporative coolers and A/C systems operate independently. A home can technically have both—but most homeowners opt to remove the evaporative cooler once A/C is installed.
   

BOTTOM LINE:
Almost every home can be upgraded with air conditioning, but the cost and complexity vary greatly depending on the existing heating setup. Knowing what system is in place—and what alternatives are available—can help set the right expectations for your buyers and open the door for helpful vendor referrals.

Pro tip: If installing A/C, consider heat pump options that provide both heating and cooling. Split system heat pumps are available that look and operate just like a traditional A/C, but with the added benefit of providing efficient heating to supplement a furnace. 

R-410A Is Out, R-454B Is In – Here’s What You Need to Know

Another big shift is happening in the HVAC world that you need to be aware of. As of January 2025 the HVAC industry began phasing out R-410A refrigerant in A/C units and is switching to R-454B.

Didn’t this just happen with R-22?

Yes. The HVAC industry just completed the transition from R-22 to R-410A in 2020, and now they’re doing it again.

Why? Simply put, R-454B was chosen as a replacement to R-410A because it offers similar cooling performance but is about 4 times more environmentally friendly from an ozone and global warming standpoint.

Here’s what this means for you and your clients:

- Older A/C Systems: If a home has an HVAC unit with R-410A, it will still work - but servicing it will get pricier as the refrigerant becomes less available.

- Newer A/C Systems: After 2025, all new units will use R-454B, which isn’t compatible with older systems. That means replacing just part of an HVAC system won’t always be an option.

- For Buyers & Sellers: If a home’s A/C is 10+ years old, it’s worth checking the refrigerant type and planning ahead for potential costs.

Fortunately this phase out will be less abrupt than the R-22 phase out, but it’s good to be aware of so you can make informed decisions over the coming years.