It’s hot in Atlanta. And humid, too.
Add hot and humid, and you get: miserable!
So with 3 or 4 months of hot & humid temperatures, what can you do to help your home’s AC keep your house comfortable?
Ideally, if you have a recent (last 10 years) AC system in your home, it was properly sized to fit the conditions of your home.
Here is some of the information the hvac company should take into consideration, as they determine the size of your hvac equipment and air ducts.
- Amount of direct sunshine on the exterior of your home.
- Orientation of the rooms, (north, south, etc)
- Number of floors the conditioned space contains.
- Percent of glass that your exterior walls contain.
- Amount and type of attic, floor, and wall insulation in your house.
- What type of windows (single pane, double pane, etc) are in your house.
- How many occupants are in your house.
There are far more specifics that your hvac tech inputs into the software, but you’re getting the right idea.
The 99% RULE
Your AC should be designed to keep your home cool during 99% of the hours in a year. The design temperature that is used as the benchmark in Atlanta is 92 degrees.
So, 1% of the hours in a year is 88 hours. The idea is that your AC is equipped to cool your home for 99% of the time. And for that rare, 1% of the time of year when it’s BLISTERING HOT and hotter than 92 degrees, your AC will simply not be enough. And it depends a lot on you and how you prepare your home – as to how comfortable you will be.
How COLD Can You Go?
The average AC system will produce temperatures from 15 degrees to 35 degrees below the outside temperature. Variables have a lot to do with IF that wonderful, cold air-flow reaches the room with your easy chair. Equipment placement and location, air duct design, location, and condition – all play a huge factor in how cool the air feels as it exits your supply vents!
A good average temperature to expect from your AC vents is 20 degrees cooler than outside temperatures. If you are getting colder air temperatures, count yourself blessed!
Unlike your car’s gas pedal being able to vary your engine speed, your hvac is not infinitely variable in speed and cooling. Most standard systems are either on or off – like a light switch. Some modern units are variable speed, and two speed – but still these units are pretty “clunky”. Either they are on or off.
Of course, if you have a mini-split “ductless” hvac, you know differently! These systems are amazingly efficient and amazingly flexible in how much they operate. They can simply “whisper” the air into the room, or blast it into the room, and anything in-between.
Here are some common tips I share with homeowners, for keeping the house cooler and not sweating through those 1% days.
- Keep your blinds closed. If you have rooms with direct sunshine hitting the windows, most definitely keep the blinds and drapes closed. Consider thermal shades or curtains.
- Check ALL of your vents. It is imperative that your vents are not obstructed with furniture, drapes, beds, dressers, etc. You want a free-flow of air into and out-of those vents!
- Use your ceiling fans. In my home, we leave them set at “lazy” speed, and the slight movement of air feels really good! And, it helps distribute air.
- Don’t let your interior temperatures get too warm. Resist the urge to turn the thermostat up while you’re gone this weekend. Even though you benefit with a lower electric bill for those two days, it will put a huge demand on your AC upon returning – adding wear-and-tear on your AC that is costly.
- Keep your doors and windows closed. Even in the evenings and early mornings. When our windows are open, humidity floods into our homes! It’s a powerful law of nature: the 2nd Law of Thermodynamics. And it teaches us that wet always moves to dry. Your AC has worked hard to dry the moisture from your interior spaces, and when you open a window or door, that thick humidity comes rushing in, trespassing inside your home. And your AC is the sheriff that has to manage those trespassers!
- Change your AC filter. Keep a clean, efficient filter in your filter-tray. Remember how miserable you were in that covid mask? Enough said! If you have a pet, regularly changing your filter gets really serious.
- Do you suspect your system’s maintenance may have been neglected? The best $300 you will spend will be when you call Vital Air Services and request a coil-cleaning. The coils inside your AC resemble the radiator in front of your car. Instead of antifreeze/coolant solution, your coils have refrigerant circulating through them. When dog hair, dust, dirt, lint, and crud start clogging up those tiny little holes, the air can’t pass freely through the coils. And this is partly why you aren’t feeling really nice, cold air from your vents. Raymond’s crew will clean those coils for easy, unobstructed airflow. See Vitalair.com
I hope this helps!
One Last Thing –
Remember, shade is your best friend during these summer months. As a Georgia Power & EMC contractor, I enjoy access to some of the world’s finest training. And we are taught that afternoon/evening shade on your roof has the equivalent effect as adding an extra TON (12,000 BTUs) of Ac to your hvac system!
While you’re waiting 30 years for that shade-tree to grow in your yard, consider calling us to install R-50 of our Applegate Bora Spray stabilized cellulose insulation in your attic. It’s an instant shade tree! And it doesn’t fall short on these 1% days, I promise.
Thanks for reading.
Bird Family Insulation