The SEER rating of a heat pump or air conditioning system is based on the efficiency of the combination of the condenser (outdoor unit) and air handler (indoor unit). They are required to be matched up by the manufacturer for performance, and the system may have a slightly higher rating than the condenser alone. A system with a 14 SEER condenser may have a 15 SEER overall rating based on the performance with its matched air handler (blower and evaporator coil unit).

    Conversely, a mismatched system of a new condenser connected to a 20-year old air handler will not provide the efficiency rating marked on the condenser. It has been required since 2006 that both the condenser and air handler be replaced when either half fails, unless it can be verified that the new half of the system that the HVAC contractor is switching out is matched by the manufacturer for performance with the remaining component.

    If part of the system was replaced by a contractor willing to do it without the required building permit, the SEER rating efficiency of the new part of the system may not be achieved because of the mismatch to the older component. If, for example, your outdoor unit is LENNOX and the indoor unit is GOODMAN, you definitely have a mismatched system and there is no way to determine the actual efficiency rating. 

    To learn more about the requirement to match condenser and air handler, click on the link below to download a pdf info sheet from the Florida Department of Community Affairs.

HVACmatch.pdf

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  To learn more about heating and air conditioning systems, see these other blog posts:

• How can I find out the SEER of my air conditioner? 

• My air conditioner won't turn on. What's wrong? 

• How can I find out the size of my air conditioner? 

• How can I tell whether the condenser (outdoor unit) is an air conditioner or heat pump? 

• Where is the air filter for my central air conditioner and furnace? I can’t find it? 

• Does an old air conditioner use more electricity as it ages? 

• How did homes stay cool in Florida before air conditioning? 

• What is wrong with an air conditioner when the air flow out of the vents is low?

• Why has the thermostat screen gone blank? 

• Why does it take so long to cool a house when an air conditioner has been off for a while? 

• Why is my air conditioner not cooling enough? 

• What are the most common problems with wall/window air conditioners?  

• Will closing doors reduce my heating and cooling costs? 

   Visit our HEATING AND AIR CONDITIONING page for other related blog posts on this subject, or go to the INDEX for a complete listing of all our articles.