To stay comfortable in the Pennsylvania and Maryland area's snowy winters and hot summers, you need your HVAC system to run at top efficiency. If your system is old or severely damaged, replacing it will keep your building's occupants more comfortable and lower your energy bills.
Replacing just the outdoor unit or indoor unit alone isn't a practical solution, though. The components of an HVAC system are designed to work together, so you'll get the greatest benefit by installing a complete system.
How Your System's Units Cooperate
A forced-air (ducted) heating and cooling system consists of two units:
- Indoor unit - This contains the furnace burner assembly, A/C evaporator coil, and the blower fan.
- Outdoor unit - In this unit is the A/C condensing coil and compressor.
Upgrading a commercial heating and cooling system is a major investment, so it can be tempting to try to cut costs by replacing a unit only when absolutely necessary. If the compressor in your outdoor unit is failing, but everything in the indoor unit still works, you might assume replacing just the outdoor unit is the most economical solution. In reality, this approach will end up costing you more overall.
Matched Systems Perform Better for Longer
HVAC equipment manufacturers design the condenser and evaporator coils, as well as other components, to work as a team. Replacing one unit and not the other is technically possible, but it results in a mismatched system.
When two units that weren't designed for each other try to operate together, they won't perform as well as a properly matched HVAC system. Replacing both units at the same time ensures a matched system that performs reliably and efficiently. You'll see benefits such as:
Fewer breakdowns and a longer lifespan - Mismatched coils place stress on the entire system, which can lead to component breakdowns. In particular, mismatching can cause floodback, a situation in which liquid refrigerant flows back into the compressor and eventually causes the compressor to fail. A properly matched system is free from this excess pressure, and therefore less likely to break down.
Optimal efficiency - Today's air conditioners are between 20 and 40 percent more efficient than those made just 10 years ago. Yet even if you buy a new high-efficiency SEER 20 outdoor unit, it will never reach its full potential efficiency if it's connected to an older, less efficient indoor unit. In a properly matched system, both units can reach their full efficiency, meaning lower energy bills for you.
Installation cost savings - Although a furnace can run for 20 years or more, it starts to lose efficiency after around 10 years. In the meantime, new and more efficient models enter the market. That means if your system is more than around 10 years old and you replace one unit now, chances are you'll still need to replace the other unit in a few years. That means added expenses and as well as more downtime for your business.
Setting up a mismatched system can involved extra work and cost. If the evaporator and condenser coil aren't correctly sized to work together, your HVAC technician may need to adjust the refrigerant charge and expansion device to reduce risk of damage.
A valid warranty - Manufacturers are well aware of the problems caused by mismatched systems and many offer warranties that are valid only if the unit is installed in a properly matched system.