Arkansas HVACR NewsMagazine March 2024

HVACR NewsMagazine March 2024

Tech News

have homes built on rolling real estate, or in areas advantageous to basement construction. Homes may incorporate partial basements or crawlspaces. Many are used as utility rooms, with water heaters and or heating and cooling systems, auxiliary storage, or unfinished space. The author has witnessed new homes as of 2020 in northwestern Arkansas with exterior walls below grade forming a crawl space beneath over half the square footage. The mechanical equipment was placed in this area and adjacent was the presence of ground water flowing from front to back of the home. Gone are the days leaving the space beneath a home unaddressed. Be cautious of finished spaces below grade without test data to support the finished claim. Humidity is similar to heat; in that it migrates for a balance. Elevated levels of moisture seek dryer space. On it is trek, it can pass through all types of construction materials. If moistures migration is slowed, damage can occur with all types of construction materials. Floors can warp or cup and loose the topcoat finish. Painted surface will fail to hold its finish. Graded areas beneath the

structure must be covered and ballasted with a heavy vapor barrier, existing ventilation grills must be sealed, and the end of the barrier should extend up continuously and attached at the plate level. All seams should be sealed with a durable tape. This is another reason to evaluate the structure if foam insulation is present at any level. If we overlook this point, damage can occur to areas anywhere below the foam. Humidity management demands an understanding of building science and an accurate Manual J to analyze the load. Manal S is necessary to select equipment that will successfully condition the space. This is especially important with Heat Pump application. Once you begin to research this aspect of newer heat pump application, the idea of stand-alone dehumidification becomes clear. This practice eliminates the need for equipment to have the capacity to dehumidify as a consequence to satisfying the sensible load. It is the contractor’s job to point out objectives and address the opportunities for stand-alone dehumidification where it is appropriate. Goals for 40% to 50% relative humidity should be on everyone’s mind.

Courtesy StegoCrawl