Matched Heating/Cooling System and Size

Matching is usually a term that relates to colors, but it’s also important when talking about heating and cooling systems. Simply put, a matched system provides the best efficiency and performance.

All air conditioners and heat pumps are specifically designed to work with matched indoor units (furnace or air handler) for optimum efficiency and performance. While a new outdoor cooling system may "work" with existing indoor units, including older systems, it will only operate at its peak potential when it’s paired with the right sized system for your home.

Bigger isn’t necessarily better when it comes to heating and cooling systems. A system that is too large for your home will frequently cycle on and off, which wastes energy. Plus, it won’t run long enough to remove humidity from the air, which can impact the comfort and health of your home.

A system that is too small can’t do its job of making you comfortable. In this case, it will run continuously to keep up with the thermostat setting, costing you more on your utility bills and potentially shortening the system’s life.

The only reliable way to determine the size that best matches the needs of your home is to have your qualified heating and cooling contractor perform a load calculation to ensure sizing is correct. The load calculation takes into account the square footage of your house, the insulation value of your windows, the amount of insulation in your walls and roof and many other factors.

The answer is most likely yes, but this is mainly due to six reasons:

Matched system design
All outdoor cooling units are specifically designed to work with matched indoor units for optimum efficiency and performance. Air conditioners and heat pumps may "work" with other indoor units, but the result is a definite compromise in overall system performance.

Design advances
In recent years, indoor blower coil units have undergone numerous design advances—especially in the areas of air handling performance, filtering efficiency and operating sound levels. A new outdoor unit will also include the latest design advances.

Higher cooling and heating efficiency
The cooling and/or heating efficiency rating assigned to a given air conditioner or heat pump is based on matched system performance. While you may gain higher efficiency by replacing only the outdoor unit, the efficiency levels (and savings) will not be as high as with a matched system.

Equipment age
If an air conditioner or heat pump outdoor unit is 10 years old and needs to be replaced, the indoor unit is just as old and has been subjected to the same amount of wear and tear. Replacing both units means you won't have to replace the indoor unit in a short time and you'll have years of good service from both units.

New warranty
A new unit also gives you a new product warranty. Replacing the indoor unit at the same time as the outdoor unit gives you added peace of mind, knowing the new warranty covers the entire system.

Cost savings
At first, replacing only an air conditioner or heat pump outdoor unit may appear to be a bargain. That is, until you consider the lower efficiency, decreased reliability and high cost of ownership associated with single-unit replacement. It may cost more to replace an entire system, but this gives you more efficiency, reliability and comfort.

You can verify that the system your contracting company is proposing is a matched system by asking them to provide you with an AHRI Certificate of Product Rating or an AHRI certified reference number. For higher efficiency systems, the certificate can be used to obtain a federal tax credit or a utility rebate. Be sure to ask your trusted heating and air conditioning contractor if they utilize AHRI to provide documentation to homeowners.