This is an old Special Forces adage, and it reinforces redundancy. Why redundancy? Well, when one of your A/C’s stop working – you will quickly understand.
When given the opportunity to assist in the design of a new space, we often suggest two smaller units as opposed to one larger unit.
That way, if one unit fails, there will always be a part of the house with A/C, giving its owners some comfort in the case of waiting for service or God forbid, a few weeks for a warranty part (quite common during Covid).
In this case, the first unit, a 3.5 Ton system was in the attic to service the second floor of a Juno Beach 3,500 sq ft condo, and we had to get somewhat creative with closet ductwork on the second floor as to service the first floor with the second unit, a 2 Ton system. This way if one unit stops working, the owners will always have comfort in one part of the house.