The shortest distance between cutting your energy bills year-round and learning where to do it is a home energy audit. These audits locate the exact source of the two most prevalent problems in many homes: air leakage and heat transfer in the building envelope.
Heat constantly moves toward cooler temperatures, and this phenomenon makes your home harder to cool and heat. Air infiltration occurs through leaks and protrusions in and out of your home. The only way to reduce the movement of heat is to have adequate insulation throughout.
What an Energy Audit Involves
An energy audit performed by licensed HVAC contractors is the most thorough evaluation you can have of your home’s energy efficiency. The auditing team will inspect your home for inefficient appliances and obvious issues that thwart energy efficiency, especially with your HVAC system.
The second step in a home energy audit involves a blower door test that measures the amount of air infiltration throughout the building’s shell. The blower door frame houses a powerful fan that pulls air outdoors. The auditors place it in an exterior door frame and turn it on after closing all the windows and vented fixtures in your home.
They watch the air pressure fall using the gauges on the blower door. Air pressure that falls quickly indicates your home has few air leaks. If it falls slowly, it means that you have many leaks throughout, normally associated with:
- Cracks around the window frames
- Worn weatherstripping around exterior doors
- Leaks in the foundation area of your home
- Problems with the sill or top plates for the framing
- Poorly fitting fireplace chimney dampers
- Holes associated with infrastructure (plumbing, cable, etc.) leaving or entering your home
- Recessed lights that enter the attic
- Loosely sealed vents exiting your home
While the blower door test is being performed, the auditing team will go through your home with thermographic devices that show where the temperature differences exist. Thermography assigns a color to temperatures, and the leaks will show up as the color associated with the outdoor temperature.
If you’re scheduling the home energy audit when temperatures are similar inside and out, you may need to thermal load your home so that enough of a temperature difference exists for the results of the blower door test to show accurately. The test results show best when there’s about a 20-degree difference between the indoors and out. The auditing team may ask you to set your temperature higher or lower to better see the thermal differences.
When an HVAC contractor performs the home energy audit, they will likely test the integrity of your ductwork with regard to air leakage and poor insulation. Air and thermal losses associated with ducts can increase your energy bills substantially since the air you’ve paid to condition escapes instead of being delivered to your rooms. Breaches in the ducts also pull in dirt and dust from the areas through which they run, and if enough collects, will slow the passage of air through them, raising energy costs.
The Results and Making Changes
Besides learning where you have air leaks, the thermographic cameras will point out areas with inadequate insulation, most commonly found in the attic and walls. Over time, insulation can compress or degrade, especially if it’s been exposed to moisture.
The energy audit will show you where you need to make improvements by air sealing and adding insulation. Caulk, expanding foam and weatherstripping do an effective job of sealing most leaks, and you can tighten up an ill-fitting fireplace damper with chimney balloons.
Adding attic insulation may be a do-it-yourself project, but you might need a professional contractor to increase the insulation in walls. An HVAC contractor can seal ducts using mastic and metal tape, as well as install special insulation to slow thermal losses in ducts.
Learn more about All American Heating & Cooling’s energy efficiency solutions, including how a home energy audit can work for you, or call us at 941-479-6060 to schedule an appointment.
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