When you’ve spent a summer’s day outside in New Orleans, Louisiana, you can’t wait to return to the cool sanctuary of your home. But without you knowing it, that sanctuary may be being breached by the hot, muggy air of the outdoors. Without a tight thermal envelope, outside air may be compromising your comfort, but most of the work for sealing it just takes a day off and a handy homeowner.
What is a Thermal Envelope?
Enough with the jargon. What exactly does "thermal envelope" mean? Well, a thermal envelope refers to everything in your home that separates indoor air from outdoor air. That includes your walls, ceilings, doors, windows, as well as your insulation. The thermal envelope contains air by keeping the HVAC-controlled air indoors and uncontrolled air outside. Specifically, the thermal envelope prevents heat transfer from the inside of the home to the outside during the winter and from the outside to the inside during the summer.
Your thermal envelope plays an important role in your comfort and energy efficiency. When properly maintained, the envelope helps your HVAC system do its job of maintaining a cozy and comfortable temperature in your home.
Why Seal Your Thermal Envelope?
Is paying attention to your thermal envelope really that important? It is if you want to guarantee comfort and save some money on your utility bills. Your thermal envelope can improve efficiency by keeping air where it belongs. When drafts form in parts of your envelope (such as between a door and the door frame), your controlled air escapes while outdoor air enters the home. In the summer, that extra heat will reduce comfort and force your HVAC system to work harder to lower the temperature. That, in turn, reduces energy efficiency and increases utility costs.
Sealing your thermal envelope makes sure that the different parts of the envelope contain air as they’re supposed to and it also means that you’ll reduce your utility costs. Plus, by helping your HVAC system run efficiently, you’ll also decrease the chances of expensive repairs while simultaneously extending the lifespan of the system.
How Can You Seal Your Thermal Envelope?
Ready to start sealing that thermal envelope? Before you get fixing anything, you need to find weak points in the envelope itself. You can identify leaks where light may shine through gaps (such as between a door and door frame or in the attic floor) and where dust and dirt have gathered near windows or doors. Even if you can’t see the breach, excess dirt can be blown in from outside through small breaks in the envelope.
Once you’ve found the leaks, it’s time to fix them. Lay fresh caulk around windows and place weatherstripping around doors. In unfinished areas – such as your garage or attic – look for gaps around where plumbing pipes meet the wood of your walls. If those holes aren’t tight, spray some expanding foam around the pipes. The same goes for electrical outlet boxes. If you have canned lighting showing in the floor of your attic and those cans aren’t tight against the floor, you may need to replace them to really seal that attic.
If your attic lacks insulation, it’s time to install some. When you buy insulation, pay attention to product’s R-value – this is a measure of the material’s resistance to heat attempting to travel through it. Attic insulation should be R-30 and wall insulation should be between R-13 and R-15. The higher the R-value, the more effective the insulation will be in trapping or resisting heat. If your attic is missing insulation, consider placing some with the proper R-value in the walls or floors. If you’re remodeling any rooms, you can also replace the insulation with one of a higher R-value for to increase efficiency.
Take control of comfort efficiency in your home by sealing your thermal envelope. All it takes is a weekend, some leak-hunting, a few simple tools, and a drive to improve your home. For an additional professional hand in improving your HVAC energy efficiency, call Bryans United Air Conditioning at 504-208-2071.
Image provided by Shutterstock