Q - I am in the market for a new air conditioning unit and I was thinking that with summer's heat coming up should I spend extra money to get a larger sized unit which would cool my house off faster, thus saving money on my energy bill.
How does that sound to you?
Jack in Kennesaw
A - This is one of those things that sound great and look great on paper, but in reality is not really going to be great.
True, a larger unit will cool your house faster. But in this instance, faster is not better.
First of all, it's your air conditioner's job to cool your air, but its other job is to keep the moisture (humidity) out of your house. Think of your a/c as a whole house dehumidifier.
We all know that too much (over 50%) humidity in a house can and will lead to problems such as mold and mildew. Your air conditioner running on a normal setting of, say, 76 degrees will run long enough to keep your humidity in check.
But by using a larger unit, it will not run long enough to keep the humidity in your house at a good level. Its run time will simply be too short to be an effective humidity controller.
Your house, instead of feeling cool and comfortable, will have that cold and clammy feel.
Plus, unless you plan on insulating your house like a meat locker, you will lose a lot of that cool air in a hurry, which will make your system run more frequently, which defeats your whole purpose.
So make sure you purchase a high efficiency system that is correctly fit for your home, and then spend the rest of your dough on better insulation.