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I believe that it is so hot because we live in Florida, we are very close to the equator and some of it may have to do with the tilt of the Earth’s axis in relation to the sun. No wait; why is it so hot in my house is a better question. Let’s look at some of the causes and remedies for a home that will not stay cool on the hotter days.
First place to stop is the air conditioning system itself. How old is the unit and is it properly sized for the space? If it is more than 12 years old, it is naturally going to be struggling to keep up and if you have noticed that it seems to be getting worse with the years it may be time to think of replacing the unit. As to proper size, a load calculation would be required for that. Outside of getting a professional to perform a load calculation, a “get you close” reference point is you need one ton of air conditioning for every 500 square feet of space in the area you are trying to cool. So, the typical 2,000 sq. ft. home would require 4 tons of air. If you suspect your unit is undersized turn to the professionals and let us figure it out for you.
Let’s head into the attic and see what is happening up there. If your home was built before last year it is almost guaranteed the space is under insulated. Florida Building Code now requires a minimum of 12” of attic insulation or a value of R-30. Prior to last year it was 5” or an R value of 19. If you take it a step further and look to the Department of Energy, 18” or R-49 is what is recommended for our climate zone. Not only will properly insulating your attic help keep your house cooler it’ll save you a minimum of 20% on the cooling costs. Again, in our typical 2,000 sq. ft. house insulation will pay for itself in 6-8 years with the cost savings.
While we are in the attic, what is going on with the duct system is always the next question. The first thing I want to know is when was the house built? In most cases the duct system is original to the house and is probably leaking like a sieve. Why would it be leaking you ask? The simple answer is age. Our lovely South Florida attics will hit 140-150 degrees very easily on a day when it’s 95 degrees outside. After 10 years or more of that heat in the attic the bonding agent that holds the duct system together just can’t do its job anymore. For every supply air-vent you have in the home there is a minimum of two connection points in the attic, most of the time it’s more than 2, however I can promise you it is a minimum of the two. Our typical home is going to have 12-14 supply air vents so we are going to have 24-28 connection points, if each connection point is leaking 1% then 24-28% of the air you are paying to cool is being lost to the attic.
I often go into homes to find a trifecta of all of the above. It still amazes me how people are so shocked after we seal the ducts, insulate the attic and install a new air conditioner about how their house feels. There are other things to consider when it comes to a house that doesn’t cool correctly such as windows and doors, what direction has the western exposure, the color of the roof and the number of people in the home.
The bottom line is in a properly designed HVAC system, you should never hear, feel or see the system, you should just walk in and every room in your home should be within a degree or so of each other and whatever the thermostat is set at. Just for the love of all things good please don’t ask me to get your house to cool much below 68 degrees; it is just not going to happen. Alright friends I’m off to the rodeo so until we meet again to me it seems pointless to try and write with a dull pencil.
House Whisperer out!!