How to Prepare Your Home for Extreme Heat in Dallas

by Lee Wallender

How to keep your Dallas house cool and comfortable while saving money during the hottest days of summer

Dallas extreme heat reno

Anyone who lives in Dallas knows about its legendary heat. March and April’s fair days in the 70s are nice but they never continue. Average maximum temperatures in Dallas in July and August hit a whopping 96 degrees F. Your air-conditioner is the largest contributor to your energy bill in the summer. While your own house will rely on that on the hottest days, Sweeten presents plenty of other ways to keep your house cool and supplement the A/C.

All of these changes will help you prepare your home from Dallas’ extreme heat. Sweeten matches home renovation projects with vetted general contractors, offering advice, support, and financial protection—at no cost to the homeowner.

Install a whole-house fan to keep cool

One way to assist your air-conditioner or even replace its operation on less intense days is with a whole-house fan.

In your house, the lower areas below the attic are artificially conditioned to a set temperature, often in the low 70s F. As the day progresses, your unconditioned attic builds up heat. By the end of the day, it is at its hottest.

Even though your attic may be insulated, a tremendous amount of heat has built up. The lower areas’ air-conditioning is working overtime to fight against it.

A whole-house fan draws air through open windows and pushes it out through the roof. The attic is completely ventilated, as well. Many whole-house fans have an air exchange rate of up to six times the volume of the house.

Speak with your contractor about the possibility of modifying the existing ducts of your HVAC system to provide whole-house cooling.

Paint your home with lighter colors

Most of us learned in school that lighter colors absorb less heat than do dark colors. To a limited degree, the same idea applies to your home.

The U.S. Department of Energy has found that dark-colored homes absorb up to 70- to 90-percent of the radiant energy that strikes the house from the sun. Heat on the outside of the house can transfer to the inside, resulting in heat gain.

Does this mean that you should paint your house white? If you wish to, you should do so. But any type of lighter colored paint or siding color will considerably reduce heat absorption. These are creams and ivories, light tans, beiges, blues, and pastels such as peaches, lavenders, and greens. 

Choose cooler roofing materials

Roofs bear the brunt of the Dallas sun. Selecting the right type of roof can reduce heat. Up to one-third of the heat that builds up in a house comes through the roof.

One common misconception is that selecting a lighter-colored roof will do the trick. Not so: a study by the U.S. Department of Energy found that even white composite shingles absorbed 70-percent of the solar radiation. Essentially, the roof is blasted with so much solar radiation, that the selection of color alone will do little.

One lower-cost solution is to have a coating applied to the shingles. Containing glass fibers and aluminium particles, this coating ward off radiant energy to a degree that lighter colored shingles cannot.

More effective, though, is to choose a type of roof material that is less thermally reactive. Terra cotta and ceramic tiles, concrete tiles, and slab concrete are good choices.

Even metal roofs are good choices due to their built-in dead-air space. This space acts as a thermal barrier to block heat transference to the house below.

Choose a siding that beats the heat

The better insulated your home is against the heat, the cooler it will be inside. While in-wall and ceiling insulation are important, siding also will prepare your home from Dallas’ extreme heat.

Vinyl siding typically leaves a space between the siding and the house. Insulated vinyl siding fills that hollow space with a rigid foam plastic insulation. This insulation is permanently attached to the back of the siding. All insulated vinyl siding products must have an R-value of 2.0 or more. R-value is a unit of measurement for thermal resistance. Higher R-value numbers mean greater insulating efficiency.

Masonry siding products such as brick and veneer stone help protect your home from the heat. Fiber-cement siding contains a great quantity of mineral materials, too. 

Add continuous exterior insulation

You cannot have enough insulation when battling the heat. While walls have been insulated internally for decades, a newer form of insulation adds even more of that much-needed R-value.

By itself, continuous insulation falls mid-range in terms of R-values—8.5 is considered typical for 2-inch thick continuous insulation. By comparison, standard two-by-four wall systems usually receive R-13 insulation.

But the real benefit lies in its name: continuous. Continuous insulation severs those thermal bridges that draw hot air into the home. Wall studs or any materials that extend from the outside to the inside through the walls can act as thermal bridges.

It only takes one view through a thermal imaging camera while standing outside on a hot day. Before continuous insulation, telltale blue ribs indicate the stud thermal bridges. After continuous exterior insulation, those blue lines disappear and your cool air stays inside your house.

Buy the best windows for Dallas’ heat

Wall systems that are fully insulated are always the best way to prepare your home from Dallas’ extreme heat. But no one wants to live in a house with no windows. Instead, buy the best possible window for that wall opening:

  • Double-paned windows are standard, no matter where you live. For maximum heat protection, choose triple-paned windows.
  • Look for windows filled with Argon gas.
  • Choosing low-e (low emissivity) glass is considered a must in hot climates. Low-e is a coating that blocks much for the ultraviolet and infrared light from the sun. By controlling these two types of light, you control the passage of heat into the house.
  • Get your numbers straight. For hot climates, keep an eye on three numbers listed on the window’s sticker: U-Factor, SHGC (Solar Heat Gain Coefficient), and VT (Visible Transmittance). You will want a low U-Factor number, a low SHGC number, and a high VT number.

Install and maintain roof vents

A whole-house fan pulls hot air from the entire house, including the attic, and expels it. Roof vents expel only air from the attic.

Ventilated attics can be as much as 30 degrees F cooler than unventilated attics. Chances are good that your home already is ventilated, and most newer homes are. The question is whether those vents are adequate for your needs.

For homeowners, calculating the number and size of needed roof vents can be difficult. Factors such as the presence of a vapor barrier, roof slope, type of roof, insulation, and more come into play. A qualified professional such as a roofing contractor can help with calculations and with installing the roof vents.

If your home has a vaulted or cathedral style ceiling or a flat roof, you will have no attic. With these types of roofs, ventilation works differently: the open plenum is within the roof itself. 

More ways to keep your house cool in extreme heat

  • Install exterior awnings over windows that receive the brunt of the sun during the hottest part of the day
  • Install ceiling fans in each room. Note that ceiling fans rotate clockwise or counter-clockwise. During the summer, you will want the ceiling fan to turn counter-clockwise.
  • Have your yard landscaped to add trees and shrubbery on the sunny side of your house
  • Add thick thermal draperies to your windows

There are many ways to keep your house cool in extreme heat, from changes to the house siding and windows and the attic. Whether upgrading your whole house or adding some supportive cooling elements, taking action will endure your summers are comfortable for years to come.

A good place to start your remodel is by setting a realistic budget. Our home renovation cost guide for Dallas can help you.

Sweeten handpicks the best general contractors to match each project’s location, budget, scope, and style. Follow the blog, Sweeten Stories, for renovation ideas and inspiration and when you’re ready to renovate, start your renovation with Sweeten.

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