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

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

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

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

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:

People always ask. “Should I Add More Attic Insulation or Install A Radiant Barrier”?  I hear this often and the answer is usually BOTH.

Regular attic insulation slows conductive heat.  Radiant barrier reflects radiant heat.  Your home gets a lot of both. Think of your home as a big refrigerator.  How much heat that flows in or out of this big box is determined by basically three things:  1) Inside surface temperature, 2) outside surface temperature and 3) R-Value and thickness of what is between the inner and outer surface.

The walls and top of the refrigerator (or your home) are typically insulated with “regular” insulation. Regular fiberglass or cellulose insulation slows conductive heat. Radiant Barrier acts like shade to reflect radiant heat and make the regular insulation more effective.  A perfect home would be built like a well-insulated refrigerator and be wrapped with radiant barrier foil insulation.  Common sense says that a refrigerator in the shade will use less energy than one in the direct sun.  This is because exterior surface temperatures can easily exceed 150º in direct sun.

If you decrease the outside surface temperature and reduce the difference between the inside/outside temperature, this has a similar effect on reducing heat flow as adding MORE “regular” attic insulation.

Too much of a good thing.

Getting attic insulation up to the recommend level for your area is always a good idea.  However, at some point you reach the law of diminishing returns.  Why?  Regular insulation slows heat, but it also HOLDS heat.  At the end of a hot-sunny day, the insulation in your attic can become a big, thick 130º blanket over the top of your home.  When the sun goes down, this “hot blanket” effect continues to hold and drive heat into the home. Once the roof cools down, the insulation can easily be the hottest part of your whole house. This can make your air conditioner run later into the night.  If you have marginal attic insulation, installing a radiant barrier will make what insulation you already have even more effective.

By combining good attic insulation and radiant barrier, you will get the best of both properties.  Reduction of conductive heat flow AND reduction of radiant heat flow by decreasing surface temperatures of the attic insulation.  Lower surface temperature is like putting the house in the shade.

So, for most homes I recommend doing both.  For maximum benefit, top off your existing insulation AND add a radiant barrier.  They will work together for maximum comfort and energy savings.

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

Mixed exhaust vents: Wind turbines and ridge vent

People who know me hear this often: “Don’t Over-Think It”. Things are usually never as complicated as they seem. Of all the questions I get from customers, Attic Ventilation is probably the most misunderstood, and overcomplicated topic in the home efficiency/improvement area. So hear me now: “DON’T OVER-THINK IT”

Attic ventilation is VERY simple. You have HOLES in the bottom of your attic (usually soffit vents) and HOLES in the top of your attic (ridge vent, wind turbines, static vents or power fans). Ideally, air comes IN the bottom and OUT the top. It’s just like a chimney in your home. Pretty simple. Holes in bottom, holes in top…got it?

Think about this. If I came to your home today and started ripping out your soffits and cutting lots of holes in the top of your roof eventually the air temperature in the attic would get close to whatever the outside (ambient) air temperature is. Air temperatures would drop but surface temperatures would not drop much due to the radiant heat gain. A radiant barrier works together with decent attic ventilation to drop both air temperature and surface temps.

Here is where many people screw up attic ventilation. More is not always better. The thought process goes something like this: “If I add an electric or solar attic fan, or some ridge vents, or a few wind turbines or static vents or maybe ALL OF THEM, I’ll move more air and my attic will be cooler” WRONG!!!!

Dirty or clogged soffit vent

Let me ask you. Have you EVER seen a chimney with a fan sticking out the side in the MIDDLE? Of course not, why? Common sense would say that the fan would pull air from BOTH the top and bottom of the chimney. Your attic is EXACTLY the same. Why on earth put an electric fan 15” away from a ridge vent or wind turbine? Yes, there will be great airflow in the top 2 feet of the attic and the rest of the air will be almost stagnant.

Air always travels the path of least resistance. Mixing exhaust vents is a bad thing. The strongest vent will dominate and the other exhaust vents will probably become INTAKE vents. This short-circuits the whole concept of air coming in the bottom and out the top. This can happen many different ways from actually mixing different types of exhaust vents to having ridge vents on EVERY ridge. Usually the ridge vents about halfway up the roof will become the intake vents and totally short circuit any air coming from the soffit vents. All the exhaust vents should be within a few feet of each other from the top.

How to fix it? Start at the bottom with your soffit vents. Have you EVER cleaned your soffit vents? 95% of homes have clogged, blocked or painted over soffit vents. Or, the holes behind the vents are so small virtually no air is coming into the attic. I’ve even seen million dollar homes where they just screwed in the vents and did not bother to even cut holes. I’ve seen many homes where just cleaning the soffit vents (use a dry nylon car wheel brush) will drop the attic temperature 20º in 20 minutes. And those wind turbines that were “broken” start spinning like crazy. Get it? Air comes in and now air will go out.

Hole cut too small behind soffit vent

Next, pick one type of exhaust vent and go with it. By combining a basic strategy of holes in top and bottom your attic will be cooler in the Summer and drier in the Winter. Remember, keep it simple, and don’t over-think it…Holes in the bottom, holes in the top.