Now that our Texas summer has arrived in full force, lets explore attic assemblies that best fit our climate.
Have you ever felt the blast of hot air when your HVAC kicks on?
If your HVAC equipment and air ducts are located in your attic space, which most homes in central Texas are, you need to understand how the extreme heat build-up in attics affects the performance of your home.
In a typical vented and traditionally insulated attic you can expect to see temperatures 30-40 degrees hotter than the outside air temperature. That’s like placing an oven directly over the space you plan to keep cool. Having a traditionally insulated attic means the insulation is placed on the ceiling of the living space, leaving the attic space outside your insulated area.
This has a number of negative effects on the performance of your home.
- It increases the workload your HVAC equipment has to manage, driving up your monthly cooling cost and shortening the life span of your HVAC equipment.
- It creates an environment that will not be conducive for storing anything you don’t want to melt.
- If you have a composition shingle roof, it will also shorten the life span of your shingles.
- You will find it best to wake up in the middle of the night to change your media filters.
The concept of venting an attic in a hot humid climate is no longer the preferred method of construction for most builders. We now prefer to create a tight sealed envelope to keep all hot, humid air infiltration to an absolute minimum. Using spray foam insulation on the backside of your roof deck and in all exterior walls is the first step in achieving a tight envelope. Spraying the roof bays and creating a tight sealed envelope will create useable attic space that will be dramatically cooler than the outside temperature.
Of course the decrease in attic temperature will vary depending on the quality of your insulation installation and the degree to which all air infiltration is sealed completely.