Home Improvement: Will My Air Conditioning System Be Sufficient When I Do My Room Addition

Will I Need A Larger Air Conditioning System Or An Additional One For The Room Addition?

The answer depends on how much additional air conditioning is required, how old the existing system is, and whether you want a back-up system if the main system has a failure.  Sometimes it’s a matter of personal choice.

Common Myth

Bigger isn't always Better

Bigger isn’t always better!

Before expanding on each option, a typical notion must be dispelled.  Air conditioning is a prime example of where more is not better.  Having too large of an air conditioning system can cause the formation of mold and mildew.  This is because an over-sized system will cool the house down quickly and shut off, but not stay on long enough to remove humidity from the air.

Industry Change

Manufacturers have stopped making one ton units due to a lack of demand.  One and a half ton units are often too large for an addition.  If this is the case, the existing system would need to be replaced with one that is one ton larger.  This is easier to justify if the existing system is 10 years old or older, but sometimes there is no other choice.

Alternative Idea

Provided the addition has at least 600 s.f. of living space, or if part of the existing house ductwork can be fed off the new system to reach 600 s.f., a separate system is the way to go.  If one A/C system goes down, you can always stay in the part of the house that has working A/C until the other one is repaired.  If you only have one A/C system and it goes down on a Friday night, you and your family could be miserable and fighting with one another, or out more money for a hotel room, if it doesn’t get repaired until Tuesday.


If you have specific questions or need a home inspection, please call me at 561-795-2551 or email me at: todd@leadingedgehomes.com and I’ll be happy to share my knowledge with you.
Leading Edge Homes, Inc. is a Florida certified building contractor specializing in improving your lifestyle through room additions, bathroom renovations, kitchen updates, hurricane-resistant screen enclosures, and more!  In business since 1991, they demolish your stress by building your trust. Contact them at 561-795-2551 or visit their website to discover how they can help you with your next home remodeling project in Palm Beach Count