With summer right around the corner, a maintenance check of your home’s air conditioning system is in order. All may be a-okay operationally, but did you know its efficiency is reliant upon something that happens behind the scenes? The unsung heroes behind what’s keeping you cool this summer are your home’s ventilation and insulation. Properly installed insulation coupled with strategically placed ventilation assure more than the efficiency of your heating and cooling systems. They are necessary for the overall health of both your home and its inhabitants.
For optimal efficiency, air circulation within a home should be exchanged once every three hours. This exchange occurs through the roof and by several means – with some processes better than others. Ideally, soffits, or a Smart Vent system in lieu of soffits, at the base or eaves of the roof allows for intake, while a ridge vent at the top of a roof facilitates the exhaust process. The process, however, is not directly proportional. “At worst, it should be a 50/50 split between air intake and exhaust. You never want the amount of ridge exhaust to exceed intake,” says Jake Domanski, a project consultant here at G. Fedale.
Homes lacking soffits may have a combination of gable vents at either end of the home and a ridge vent, or attic exhaust fans. While these options offer cross-draft airflow, they are not the most efficient. Due to their location – either mid-to-upper wall in an attic if gable vents, or at the peak of the attic as is the case with fans – they are more restrictive when it comes to overall airflow. “The whole idea is to pull air from the bottom of the attic up and out the roof,” Jake says, adding that attic fans are more typical for a hip roof, while a standard A-frame home is more apt to have a ridge vent. Insufficient ventilation can cause moisture issues, shorten the life of your roof, and ultimately impact the warranty of a new roof.
Insulation, equally essential for optimal efficiency, should be present in walls, knee walls, and attics. Density requirements vary depending on a given state’s building codes. In Delaware, attic insulation should have an R-value of 38. Given colder climates in parts north, that R-value is higher. Pennsylvania’s minimum for attic insulation is R-49. The coding map is everchanging, Jake says and, as a result, he often recommends an R-value of 49 as well. “The standards have become stricter because the benefit is not just to the homeowner, but to the environment and our energy use,” Jake says.
While ventilation may seem straightforward, the extent of insulation and its installation presents a more complex situation. Too much insulation without adequate ventilation creates a tight house. Proper installation is critical. Insulation should stop at the wall line, Jake says, as the perimeter of the roofline must be kept open either by way of soffits or Smart Vent to allow for that necessary airflow. And, since 40 percent of a home’s energy is lost because of inadequate insulation, it holds the golden ticket when it comes to return on investment.