Four Silver Bullets For Saving Energy In Hot Climates

The weather outside may be frightful, but in your attic it’s quite delightful. Well, it is compared to being in your attic in July. NOW is the time to think ahead and work on a few simple projects that can have a HUGE difference before you get your summer electric bills.

I’m about to reveal the FOUR SILVER BULLETS for making your home more energy efficient in HOT CLIMATES. I’m especially talking about your typical one-story, ranch style home in the South.

Picture yourself sitting in your living room on hot August afternoon. The sun is beating down and it’s about 95º outside. What’s between you and the bazillion degree sun?
Four layers: 1) Roof 2) Attic 3) Leaking Ductwork in the Attic 4) Insulation
If you fix each “layer” between you and the heat from the sun, your home WILL BE MORE EFFICIENT AND COMFORTABLE EVERY TIME!!! Guaranteed. It is not complicated; just follow the recipe for success.

Radiant Barrier Installation
Radiant Barrier Installation

Layer #1 – Roof
Problem: It gets to be about 150º or more and basically acts like a big sponge to absorb heat. This heat is then radiated to the next layer.

Silver Bullet #1 = Radiant Barrier
Installing a radiant barrier is the next best thing to a giant tree instantly landing over your home. In certain roofing systems, radiant barrier can be applied directly under the shingles since there is an air gap.Your roof will still absorb the heat, but now rather than that heat being transferred to the home, it will be reflected AWAY.

Layer #2 – Attic

Blocked soffit vent blocks attic ventilation
Blocked soffit vent blocks attic ventilation

Problem: Because most attics don’t have enough (or proper) ventilation, the AIR inside the attic basically gets “Clogged” like a drain in a bathtub. The air has nowhere to go and it just heats up and “fills up” the attic. Hot air in the attic will heat up the insulation AND heat up your ductwork that is supposed to have nice cold air running through it.

Silver Bullet #2 = Attic Ventilation
Attic ventilation is real simple. All you need is holes in the top and holes in the bottom. The more holes, the more outside (relatively cool) air moves through the attic and the cooler the attic air. The lowest the air inside the attic can go is near ambient (outside) temperature. The overlooked key to fixing attic ventilation is usually more soffit vents.

Leaking ducts in the attic
Leaking ducts in the attic

Layer #3 – Leaking Ductwork In The Attic
Problem: Putting Ductwork in the attic is about a dumb as making ice cream in the oven. Since you can’t move the ductwork, at least keep it from leaking. Most homes have duct leakage ranging from 15-50%. Older homes and homes with old metal ductwork usually have the highest leakage. What this means is that probably 25% or more of the cold air you are buying is being blown into the attic OR Hot dirty attic air is being SUCKED into your home if the leaks are on the return side of the AC system.

Silver Bullet #3 = Seal Ducts In Attic
If 30% of your water from your sprinkler were spraying into the street, you would fix it today. Why not do the same for your ductwork? Have your ductwork sealed or replaced. A tight duct system will save energy and increase comfort. Plus, indoor air quality will improve by reducing humidity and dust from being pulled into the home.

Attic Insulation being blown in
Attic Insulation being blown in

Layer #4 – Attic Insulation
Problem: Most homes do not have enough attic insulation to create a good thermal barrier between either the heat in the summer and the cold in the winter.

Silver Bullet #4 = Attic Insulation
Increase your attic insulation to the recommend level for your area. Check the DOE (Department Of Energy) for recommendations.

There you go. Four silver bullets for fixing your summer electric bill. Your attic is waiting.

I've written several other posts on this that you might be interested in. Check these posts below:

  • Do I need more ventilation to cool my attic?
  • Why I don’t recommend electric attic fans
  • How To Vent an Attic Without Soffit Vents
  • 6 Myths About Attic Ventilation
  • The #1 Attic Ventilation Problem
  • 5 thoughts on “Four Silver Bullets For Saving Energy In Hot Climates

    1. Good points. I’ve been working on insulating a crawl space just to seal off the moisture and also for the possible varmints (we do have them down here in Georgia).

    2. Ed-

      I just bought a home built in 1929 and the inspector commented on the lack of vents and the high temp in the attic. This was in February. Summer in TX is going to be even worse. The attic only has two rotating vents on the top and no soffit vents.

      So my plan is adding soffit vents and better roof vents and adding a perforated radiant foil. No Central AC, so no ducts and the house currently has knob and tube, so I’ll wait on extra insulation until that is out this fall.

      So my question is, would it make sense to apply a mold prevention paint to the underside of the roof before the radient barrier? the current roof is in good shape, but to keep it that way I’d want to prevent any mold from forming where I cannot see it under the foil. Houston gets a ton of rainfall (40-60 inches). I’d like to keep it outside.

      1. I don’t think the paint would be a good investment, especially since simple air sealing and good attic ventilation go a long way in helping reduce the probability of moisture causing complications. The first, and best, method is to SEAL up all the holes in your ceiling. In fact, you should do this even if you’re not installing radiant barrier. Sealing up leaky holes reduces the amount of air leaking out of your home, and ultimately reduces your energy costs. Next, make sure than any vents from the inside of the home are vented to the outside of the attic. Finally, proper ventilation in an attic is essential to creating a dry space – so make that a priority! Air should come in the attic at the soffit level and leave near the peak of the attic. This natural flow allows for moisture to freely move about and eventually diffuse. Incidentally, this is why radiant barrier is perforated and why you should always use a perforated product in a vented attic. The perforations in the foil are tiny pinholes that allow water vapor molecules to pass through. In an attic situation this is exactly what you want: moisture moving freely to contribute to an overall dry attic space. So work on that ventilation through the attic, seal up air leaks from the house and then add your radiant barrier.

    3. I am interested in beefing up my 1/2″ subfloor with a layer of usb before I lay some laminate wood flooring. We are on block and beam 1978 construction. Already upped attic insulation but single layer subfloor in this end of house is always cold. Wondering if out 8 month summer 4 month winter in SE TX would be better combatted with tech shield to a either reflect toward desired conditioned air space or reflect down against existing subfloor to reduce exterior temp influence?

      1. To help rooms above the crawlspace stop heat loss in to the crawlspace, you should just staple AtticFoil across the insulation-filled floor joists in the crawlspace. Install info shown here: Radiant Barrier Under the House to Stop Heat Loss.
        If you went with TechShield, that would work too, but remember, you need to have an open air GAP (no insulation, no foam, nothing!) on the foil side, or else it will not help at all.

    Leave a Reply

    Your email address will not be published. Required fields are marked *