A typical air conditioning system will last twenty years or less, even if well-maintained. Beyond this point, repair costs tend to become too high, or critical components can start to fail. Of course, every rule has exceptions. Systems that are exceptionally well-maintained or that only see infrequent usage may last much longer, and some homeowners may simply get lucky.
As a result, your home may have an old system running well beyond its expected lifespan. When these systems inevitably fail and require replacement, they can come with many challenges that newer systems won't face. If you're about to replace an ancient air conditioning system, here are three factors you may need to consider.
1. Refrigerant Plumbing
Your refrigerant is the lifeblood of your AC system. This chemical absorbs and releases energy as it transitions between liquid and vapor states, allowing your system to transport heat away from your home. AC systems have utilized numerous refrigerant types over the years, including several with known environmental concerns.
When replacing an AC system, keeping the line set (the refrigerant plumbing) is often possible. However, this cost-saving measure may not be available if your system uses discontinued refrigerants such as R12 or R22. In these cases, you'll usually need to replace everything, including the line set, to avoid contamination and prevent issues with your new system.
2. Ductwork Sizing
Modern air condition systems require between 350 and 400 CFM (cubic feet per minute) of airflow to function correctly. Installers may adjust the overall system airflow slightly to accommodate environmental conditions such as humidity, but most modern systems will fall into this range. Unfortunately, older systems don't always meet these requirements.
Installer a newer system with a more powerful blower can stress older ductwork or create airflow restrictions. Your system may run poorly without adequate airflow or even suffer premature failures. If replacing an older system, ensure your installer checks your ductwork for compatibility. If there's a sizing issue, you'll need to replace your home's existing ductwork.
3. Furnace Incompatibility
Central air systems and furnaces typically share numerous components, including the ductwork and whole house blower. Most installers recommend matching systems since compatibility issues can arise between the heating and cooling sides of the system, especially if one unit is much newer than the other.
While replacing your furnace with your AC isn't always necessary, you're more likely to face problems dealing with a very old system. You may also need to consider replacing your furnace if your new air conditioner has advanced features, such as a variable stage compressor. Make sure you discuss compatibility concerns with your installer before choosing your new AC system.
For more information on residential AC, contact a professional near you.